CN105488488A - Remote sensing recognition method and apparatus for black and odorous water body in city - Google Patents

Abstract

Embodiments of the invention disclose a remote sensing recognition method and apparatus for a black and odorous water body in a city. The method comprises: obtaining remote sensing data of a to-be-identified point of a water surface; based on the obtained remote sensing data, calculating a spectral tristimulus value of the to-be-identified point of the water surface; based on the spectral tristimulus value, calculating the saturation of the to-be-identified point of the water surface; and if the saturation is less than a preset threshold value, determining the to-be-identified point of the water surface to be the black and odorous water body. According to the remote sensing recognition method and apparatus for the black and odorous water body in the city, provided by the embodiments of the invention, the saturation is calculated based on the remote sensing data, and whether the water body is the black and odorous water body or not is identified based on the saturation, so that the difference between the black and odorous water body in the city and other water bodies is essentially revealed, the identification of the black and odorous water body in the city is realized, and a blank of the remote sensing recognition method for the black and odorous water body in the city is filled up.

Description

City black and odorous water remote sensing recognition method and device

Technical field

The present invention relates to remote sensing technology field, more particularly, relate to a kind of city black and odorous water remote sensing recognition method and device.

Background technology

In the process of city prosperity, industry, agricultural and sanitary wastewater make the river in completed region of the city no longer limpid, even black, and distribute stench, become city black and odorous water.Traditional research for black and odorous water is environment, ecological relevant research mainly, lays particular emphasis on biochemical genetic analysis and differentiation, and the research about remote sensing monitoring city black and odorous water is very rare.

Utilizing in remote sensing image identification black and odorous water, utilizing remote sensing images identification " lake is general " at present, lake is general can think a kind of special black and odorous water, but does not belong to typical city black and odorous water.

Inventor is realizing finding in process of the present invention, identifies the poor universality of the method that lake is general at present, can only identify lake pan class black and odorous water, and can not identify city black and odorous water.Therefore, how to identify that city black and odorous water becomes problem demanding prompt solution.

Summary of the invention

The object of this invention is to provide a kind of city black and odorous water remote sensing recognition method and device, to identify city black and odorous water.

For achieving the above object, the invention provides following technical scheme:

A kind of city black and odorous water remote sensing recognition method, comprising:

Obtain the remotely-sensed data of water surface point to be identified;

The spectral tristimulus value of described water surface point to be identified is calculated based on described remotely-sensed data;

The saturation degree of described water surface point to be identified is calculated based on described spectral tristimulus value;

If described saturation degree is less than predetermined threshold value, determine that described water surface point to be identified is black and odorous water.

Said method, preferably, the remotely-sensed data of described water surface point to be identified comprises: the tristimulus values of corresponding pixel to be identified with the described water surface in water surface remote sensing images;

The described spectral tristimulus value calculating described water surface point to be identified based on described remotely-sensed data comprises:

Described tristimulus values is converted to spectral tristimulus value by the transformational relation according to tristimulus values and tristimulus values.

Said method, preferably, the remotely-sensed data of described water surface point to be identified comprises: the actual measurement Remote Sensing Reflectance of each wave band of described water surface point to be identified;

The described spectral tristimulus value calculating described water surface point to be identified based on described remotely-sensed data comprises:

The actual measurement Remote Sensing Reflectance of each wave band described is converted to satellite band equivalent reflectivity;

The corresponding relation of foundation equivalent reflectivity and wave band, obtains the tristimulus values corresponding with trichromatic wave band of described water surface point to be identified;

Described tristimulus values is converted to spectral tristimulus value by the transformational relation according to tristimulus values and tristimulus values.

Said method, preferably, the described saturation degree calculating described water surface point to be identified based on described spectral tristimulus value comprises:

Described spectral tristimulus value is converted to the first chromaticity coordinate of described water surface point to be identified;

Calculate the second chromaticity coordinate of the predominant wavelength of described first chromaticity coordinate institute characterizing color;

Determine the first distance between the equal-energy white point in described first chromaticity coordinate and chromatic diagram, and the second distance between equal-energy white point in described second chromaticity coordinate and chromatic diagram;

Described first distance and the ratio of described second distance are defined as the saturation degree of described water surface point to be identified.

Said method, preferably, the second chromaticity coordinate that the predominant wavelength of the described first chromaticity coordinate institute characterizing color of described calculating is corresponding comprises:

Calculate with the equal-energy white point in chromatic diagram for starting point, the angle of preset coordinate axle in the vector being terminal with described first chromaticity coordinate and described chromatic diagram;

According to the corresponding relation of preset angle and dominant wavelength, determine the dominant wavelength corresponding with described angle;

According to the corresponding relation of preset dominant wavelength and chromaticity coordinate, determine the chromaticity coordinate corresponding with determined dominant wavelength.

A kind of city black and odorous water remote sensing recognition device, comprising:

Acquisition module, for obtaining the remotely-sensed data of water surface point to be identified;

First computing module, for calculating the spectral tristimulus value of described water surface point to be identified based on described remotely-sensed data;

Second computing module, for calculating the saturation degree of described water surface point to be identified based on described spectral tristimulus value;

Determination module, if be less than predetermined threshold value for described saturation degree, determines that described water surface point to be identified is black and odorous water.

Said apparatus, preferably, the remotely-sensed data of described water surface point to be identified comprises: the tristimulus values of corresponding pixel to be identified with the described water surface in water surface remote sensing images;

Described first computing module comprises:

First converting unit, for the transformational relation according to tristimulus values and tristimulus values, is converted to spectral tristimulus value by described tristimulus values.

Said apparatus, preferably, the remotely-sensed data of described water surface point to be identified comprises: the actual measurement Remote Sensing Reflectance of each wave band of described water surface point to be identified;

Described first computing module comprises:

Second converting unit, for being converted to satellite band equivalent reflectivity by the actual measurement Remote Sensing Reflectance of each wave band described;

Acquiring unit, for the corresponding relation according to equivalent reflectivity and wave band, obtains the tristimulus values corresponding with trichromatic wave band of described water surface point to be identified;

3rd converting unit, for being converted to spectral tristimulus value according to the transformational relation of tristimulus values and tristimulus values by described tristimulus values.

Said apparatus, preferably, described second computing module comprises:

4th converting unit, for being converted to the first chromaticity coordinate of described water surface point to be identified by described spectral tristimulus value;

Computing unit, for calculating the second chromaticity coordinate of the predominant wavelength of described first chromaticity coordinate institute characterizing color;

First determining unit, for determining the first distance between the equal-energy white point in described first chromaticity coordinate and chromatic diagram, and the second distance between equal-energy white point in described second chromaticity coordinate and chromatic diagram;

Second determining unit, for being defined as the saturation degree of described water surface point to be identified by described first distance and the ratio of described second distance.

Said apparatus, preferably, described computing unit comprises:

Computation subunit, for calculating with the equal-energy white point in chromatic diagram for starting point, the angle of preset coordinate axle in the vector being terminal with described first chromaticity coordinate and described chromatic diagram;

First determines subelement, for the corresponding relation according to preset angle and dominant wavelength, determines the dominant wavelength corresponding with described angle;

Second determines subelement, for the corresponding relation according to preset dominant wavelength and chromaticity coordinate, determines the chromaticity coordinate corresponding with determined dominant wavelength.

Known by above scheme, a kind of city black and odorous water remote sensing recognition method that the application provides and device, obtain the remotely-sensed data of water surface point to be identified; The spectral tristimulus value of water surface point to be identified is calculated based on obtained remotely-sensed data; The saturation degree of water surface point to be identified is calculated based on spectral tristimulus value; If saturation degree is less than predetermined threshold value, determine that water surface point to be identified is black and odorous water.Visible, the city black and odorous water remote sensing recognition method that the embodiment of the present invention provides and device, saturation degree is calculated based on remotely-sensed data, whether be that black and odorous water identifies based on saturation degree to water body, inherently disclose the different of black and odorous water and other water body in city, achieve the identification of city black and odorous water, fill up the blank of city black and odorous water remote sensing recognition method.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

A kind of realization flow figure of the city black and odorous water remote sensing recognition method that Fig. 1 provides for the embodiment of the present invention;

A kind of realization flow figure calculating the saturation degree of water surface point to be identified based on spectral tristimulus value that Fig. 2 provides for the embodiment of the present invention;

Fig. 3 is the schematic diagram of the CIE1931 chromatic diagram that International Commission on Illumination formulates;

A kind of realization flow figure of the second chromaticity coordinate that the predominant wavelength of the calculating first chromaticity coordinate institute characterizing color that Fig. 4 provides for the embodiment of the present invention is corresponding;

A kind of structural representation of the city black and odorous water remote sensing recognition device that Fig. 5 provides for the embodiment of the present invention;

A kind of structural representation of the first computing module that Fig. 6 provides for the embodiment of the present invention;

The another kind of structural representation of the first computing module that Fig. 7 provides for the embodiment of the present invention;

A kind of structural representation of the second computing module that Fig. 8 provides for the embodiment of the present invention;

A kind of structural representation of the computing unit that Fig. 9 provides for the embodiment of the present invention.

Term " first ", " second ", " the 3rd " " 4th " etc. (if existence) in instructions and claims and above-mentioned accompanying drawing are for distinguishing similar part, and need not be used for describing specific order or precedence.Should be appreciated that the data used like this can be exchanged in the appropriate case, so that the embodiment of the application described herein can be implemented with the order except illustrated here.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not paying the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

Refer to Fig. 1, a kind of realization flow figure of the city black and odorous water remote sensing recognition method that Fig. 1 provides for the embodiment of the present invention, can comprise:

Step S11: the remotely-sensed data obtaining water surface point to be identified;

Water surface point to be identified refers to any point in waters to be identified in completed region of the city, the remotely-sensed data of water surface point to be identified can be corresponding pixel to be identified with this in the remote sensing images in waters to be identified three primary colors (namely red, green and blue) value (as, trichromatic reflectivity), also can be the actual measurement Remote Sensing Reflectance of each wave band of this point to be identified.

Step S12: the spectral tristimulus value calculating water surface point to be identified based on obtained remotely-sensed data;

In order to carry out digitized representations accurately to color, and International Commission on Illumination (TheCommissionInternationaledeL ' E^clairage, CIE) develop a set of Standard Colors system CIE-XYZ color system.Have selected three desirable primary colors [X] in CIE-XYZ system, [Y], [Z] instead of three primary color red [R] in CIE-RGB system, green [G], blue [B], the tristimulus values XYZ making spectrum in colorimeter system entirely on the occasion of, and X, Z two primary colors only represent colourity, do not have brightness, luminance brightness only becomes ratio with tristimulus values Y.

Step S13: the saturation degree calculating water surface point to be identified based on spectral tristimulus value;

Step S14: if saturation degree is less than predetermined threshold value, determines that water surface point to be identified is black and odorous water.

Wherein, predetermined threshold value can be determined according to the experience of measured data.Such as, by Shenyang black and odorous water field survey, determine that the predetermined threshold value corresponding with this region is 0.1.Certainly, after having changed new survey region, this threshold value may change to some extent.

The city black and odorous water remote sensing recognition method that the embodiment of the present invention provides, obtains the remotely-sensed data of water surface point to be identified; The spectral tristimulus value of water surface point to be identified is calculated based on obtained remotely-sensed data; The saturation degree of water surface point to be identified is calculated based on spectral tristimulus value; If saturation degree is less than predetermined threshold value, determine that water surface point to be identified is black and odorous water.Visible, the city black and odorous water remote sensing recognition method that the embodiment of the present invention provides, saturation degree is calculated based on remotely-sensed data, whether be that black and odorous water identifies based on saturation degree to water body, inherently disclose the different of city black and odorous water and other water body, achieve the identification of city black and odorous water, fill up the blank of city black and odorous water remote sensing recognition method.

Optionally, if the remotely-sensed data of water surface point to be identified is the tristimulus values of corresponding pixel to be identified with the water surface in water surface remote sensing images, then the implementation calculating the spectral tristimulus value of water surface point to be identified based on remotely-sensed data can be:

Tristimulus values is converted to spectral tristimulus value by the transformational relation according to tristimulus values and tristimulus values.

The relation formula of CIE-RGB and the CIE-XYZ of CIE definition is as follows:

X＝2.7689R+1.7517G+1.1302B

Y＝1.0000R+4.5907G+0.0601B(1)

Z＝0.0000R+0.0565G+5.5934B

In the embodiment of the present invention, according to formula (1), tristimulus values can be converted to spectral tristimulus value.

Optionally, if the remotely-sensed data of water surface point to be identified is the actual measurement Remote Sensing Reflectance of each wave band of water surface point to be identified; The implementation then calculating the spectral tristimulus value of water surface point to be identified based on remotely-sensed data can be:

The actual measurement Remote Sensing Reflectance of each wave band is converted to satellite band equivalent reflectivity;

Optionally, can be changed actual measurement Remote Sensing Reflectance by following formula:

$R_{eq}=\frac{\∫R_{rs}\left(\mathrm{\λ}\right)f_{SRF}\left(\mathrm{\λ}\right)d\mathrm{\λ}}{\∫f_{SRF}\left(\mathrm{\λ}\right)d\mathrm{\λ}}---\left(2\right)$

Wherein, R _eqfor satellite band equivalent measurement reflectivity, R _rs(λ) be actual measurement Remote Sensing Reflectance, f _sRF(λ) be satellite band spectral response functions.

The corresponding relation of foundation equivalent reflectivity and wave band, obtains the tristimulus values corresponding with trichromatic wave band of described water surface point to be identified; The tristimulus values corresponding with trichromatic wave band is the equivalent reflectivity corresponding with trichromatic wave band.

The reflectivity that different wave bands is corresponding different.Therefore, according to trichromatic wavelength, and the corresponding relation of wavelength and reflectivity, trichromatic reflectivity can be determined, in the embodiment of the present invention, using trichromatic reflectivity as tristimulus values.

Trichromatic grayvalue transition is spectral tristimulus value by the transformational relation according to tristimulus values and tristimulus values.

In the embodiment of the present invention, according to formula (1), tristimulus values can be converted to spectral tristimulus value.

Optionally, what the embodiment of the present invention provided calculates a kind of realization flow figure of the saturation degree of water surface point to be identified as shown in Figure 2 based on spectral tristimulus value, can comprise:

Step S21: the first chromaticity coordinate spectral tristimulus value being converted to water surface point to be identified;

Tristimulus values in CIE-XYZ system is very useful to define color, but not easily its result visual.For this reason, CIE defined two-dimensional chromaticity figure in 1931, was used for depicting color on X-Y scheme, but color wherein and brightness have nothing to do, and on chromatic diagram, two-dimensional coordinate x and y calculates from tristimulus values XYZ the chromaticity coordinate got, and computing formula is as follows:

$\begin{array}{c}x=\frac{X}{X+Y+Z}\\ y=\frac{Y}{X+Y+Z}\\ z=\frac{Z}{X+Y+Z}\end{array}---\left(3\right)$

Due to x+y+z=1, with x, y two values just can determine a color, therefore all colours in visible-range can be represented with CIE-xy chromatic diagram (Fig. 3), often kind of all corresponding chromaticity coordinate (x of color, y), all drop in the scope of horseshoe-shaped spectrum locus encirclement.In figure, S is called equal-energy white luminous point, and its chromaticity coordinate is (0.3333,0.3333), represents three kinds of primary colors mixed in equal amounts; C point is a color chromaticity coordinates point, and coordinate is (x, y), and the extended line of SC hands over spectrum locus (i.e. monochromatic track) in D point, and the wavelength of D point spectrum colour is exactly the predominant wavelength of C point color.Dominant wavelength is the important indicator of color quantizing, and visible light colors represents with 1 nanometer intervals by it from 380nm to 700nm, can represent a kind of tone of color with concrete wavelength form.

Step S22: the second chromaticity coordinate calculating the predominant wavelength of the first chromaticity coordinate institute characterizing color;

If the first chromaticity coordinate is C point coordinate in Fig. 3, then the second chromaticity coordinate of the predominant wavelength of the first chromaticity coordinate institute characterizing color is D point coordinate.

Step S23: determine the first distance between the equal-energy white point in the first chromaticity coordinate and chromatic diagram, and the second distance between equal-energy white point in the second chromaticity coordinate and chromatic diagram;

Step S24: the saturation degree the first distance and the ratio of second distance being defined as water surface point to be identified.

Figure 3 shows that example, the ratio SC/SD of the saturation degree of C point to be C point to distance SC and the D of S point the put distance SD of S point.

Optionally, a kind of realization flow figure of the second chromaticity coordinate that the predominant wavelength of the calculating first chromaticity coordinate institute characterizing color that the embodiment of the present invention provides is corresponding as shown in Figure 4, can comprise:

Step S41: calculate with the equal-energy white point in chromatic diagram for starting point, the angle of preset coordinate axle in the vector being terminal with the first chromaticity coordinate and chromatic diagram;

For ease of describing, as shown in Figure 3, a new rectangular coordinate system o'x'y' is set up in chromatic diagram, wherein, coordinate origin o' is arranged in the equal-energy white point S of chromatic diagram, x' axle is with chromatic diagram y-axis is parallel and direction is consistent, and y' axle is with x-axis in chromatic diagram is parallel and direction is consistent, and chromatic diagram is divided into four quadrants by x' axle meet at o' point vertical with y' axle.

The chromaticity coordinate (x, y) of each nano wave length of chromatic diagram object-line (i.e. spectrum locus) is converted to the coordinate (x', y') under new coordinate system, conversion formula is:

x'＝y-0.3333

y'＝x-0.3333

(4)

In o'x'y' coordinate system, suppose that vector (x', y') and x' positive axis angle are α, then angle α computing formula is: α=ARCTAN2 (y', x')=ARCTAN2 (x-0.3333, y-0.3333) (4)

Wherein, ARCTAN2 function representation bivariate arctan function, the codomain of bivariate tan is (-180 °, 180 °), i.e. vector (x', y') bear axle from x' and be rotated counterclockwise the process bearing axle through x' positive axis again to x', arctan function changes to-180 ° from-180 °.

Because the x' axle in o'x'y' coordinate system is parallel with the y-axis in chromatic diagram, therefore, vector (x', y') and x' positive axis angle equal the angle of the y-axis in vector (x', y') and chromatic diagram.

After coordinate conversion, ARCTAN2 function can make α angle increase progressively along with dominant wavelength, namely corresponding from 380nm to 700nm α contends greatly cumulative, like this, the α angle look-up table of an incremental order corresponding from 380nm to 700nm can be set up, i.e. the mapping table of angle and dominant wavelength.

In the embodiment of the present invention, also wave spectrum chromaticity coordinate each in the spectrum locus of CIE-xy chromatic diagram is set up the look-up table of a corresponding spectral chromaticity coordinates of wavelength from 380nm to 700nm, i.e. the mapping table of dominant wavelength and chromaticity coordinate.

Step S42: according to the corresponding relation of preset angle and dominant wavelength, determine the dominant wavelength corresponding with determined angle;

Concrete, if there is not determined angle value in the corresponding relation of preset angle and dominant wavelength, then the dominant wavelength selecting the angle nearest with determined angle corresponding is the dominant wavelength corresponding with determined angle.Such as, suppose that determined angle α is 6 degree, and in the corresponding relation of preset angle and dominant wavelength, what 558nm was corresponding is 5.51 degree.What 559nm was corresponding is 7.01 degree, and 6 degree from 5.51 degree more close to, therefore determine that the dominant wavelength corresponding with determined angle is 558nm.

Step S43: according to the corresponding relation of preset dominant wavelength and chromaticity coordinate, determine the chromaticity coordinate corresponding with determined dominant wavelength.

Corresponding with embodiment of the method, the embodiment of the present invention also provides a kind of city black and odorous water remote sensing recognition device, and a kind of structural representation of the city black and odorous water remote sensing recognition device that the embodiment of the present invention provides as shown in Figure 5, can comprise:

Acquisition module 51, the first computing module 52, second computing module 53 and determination module 54; Wherein,

Acquisition module 51 is for obtaining the remotely-sensed data of water surface point to be identified;

Water surface point to be identified refers to any point in waters to be identified, the remotely-sensed data of water surface point to be identified can be three primary colors (namely red, the green and blue) value of corresponding pixel to be identified with this in the remote sensing images in waters to be identified, also can be the actual measurement Remote Sensing Reflectance of each wave band of this point to be identified.

First computing module 52 is for calculating the spectral tristimulus value of water surface point to be identified based on remotely-sensed data;

In order to carry out digitized representations accurately to color, and International Commission on Illumination (TheCommissionInternationaledeL ' E^clairage, CIE) develop a set of Standard Colors system CIE-XYZ color system.Have selected three desirable primary colors [X] in CIE-XYZ system, [Y], [Z] instead of three primary color red [R] in CIE-RGB system, green [G], blue [B], the tristimulus values XYZ making spectrum in colorimeter system entirely on the occasion of, and X, Z two primary colors only represent colourity, do not have brightness, luminance brightness only becomes ratio with tristimulus values Y.

Second computing module 53 is for calculating the saturation degree of water surface point to be identified based on spectral tristimulus value;

If determination module 54 is less than predetermined threshold value for saturation degree, determine that water surface point to be identified is black and odorous water.

Wherein, predetermined threshold value can be determined according to the experience of measured data.Such as, by Shenyang black and odorous water field survey, determine that the predetermined threshold value corresponding with this region is 0.1.Certainly, after having changed new survey region, this threshold value may change to some extent.

The city black and odorous water remote sensing recognition device that the embodiment of the present invention provides, obtains the remotely-sensed data of water surface point to be identified; The spectral tristimulus value of water surface point to be identified is calculated based on obtained remotely-sensed data; The saturation degree of water surface point to be identified is calculated based on spectral tristimulus value; If saturation degree is less than predetermined threshold value, determine that water surface point to be identified is black and odorous water.Visible, the city black and odorous water remote sensing recognition device that the embodiment of the present invention provides, saturation degree is calculated based on remotely-sensed data, whether be that black and odorous water identifies based on saturation degree to water body, inherently disclose the different of black and odorous water and other water body in city, achieve the identification of city black and odorous water, fill up the blank of city black and odorous water remote sensing recognition method.

Optionally, a kind of structural representation of the first computing module 52 that the embodiment of the present invention provides as shown in Figure 6, can comprise:

First converting unit 61, if the remotely-sensed data for water surface point to be identified is the tristimulus values of corresponding pixel to be identified with the water surface in water surface remote sensing images, according to the transformational relation of tristimulus values (being specially gray-scale value) with tristimulus values, tristimulus values is converted to spectral tristimulus value.

According to formula (1), tristimulus values can be converted to spectral tristimulus value.

Optionally, the another kind of structural representation of the first computing module 52 that the embodiment of the present invention provides as shown in Figure 7, can comprise:

Second modular converter 71, if the actual measurement Remote Sensing Reflectance for the remotely-sensed data of water surface point to be identified being each wave band of water surface point to be identified, is converted to satellite band equivalent reflectivity by the actual measurement Remote Sensing Reflectance of each wave band;

According to formula (2), the actual measurement Remote Sensing Reflectance of each wave band can be converted to satellite band equivalent reflectivity.

Acquisition module 72, for the corresponding relation according to equivalent reflectivity and wave band, obtains the tristimulus values corresponding with trichromatic wave band of described water surface point to be identified; The tristimulus values corresponding with trichromatic wave band is the equivalent reflectivity corresponding with trichromatic wave band.

The reflectivity that different wave bands is corresponding different.Therefore, according to trichromatic wavelength, and the corresponding relation of wavelength and reflectivity, trichromatic reflectivity can be determined, in the embodiment of the present invention, using trichromatic reflectivity as tristimulus values.

Trichromatic grayvalue transition is spectral tristimulus value for the transformational relation according to tristimulus values and tristimulus values by the 3rd modular converter 73.

According to formula (1), tristimulus values can be converted to spectral tristimulus value.

Optionally, a kind of structural representation of the second computing module 53 that the embodiment of the present invention provides as shown in Figure 8, can comprise:

4th converting unit 81, computing unit 82, the first determining unit 83 and the second determining unit 84; Wherein,

4th converting unit 81 is for being converted to the first chromaticity coordinate of water surface point to be identified by spectral tristimulus value;

Tristimulus values in CIE-XYZ system is very useful to define color, but not easily its result visual.For this reason, CIE defined two-dimensional chromaticity figure in 1931, was used for depicting color on X-Y scheme, but color wherein and brightness have nothing to do, and on chromatic diagram, two-dimensional coordinate x and y calculates from tristimulus values XYZ the chromaticity coordinate got, and computing formula is as follows:

$\begin{array}{c}x=\frac{X}{X+Y+Z}\\ y=\frac{Y}{X+Y+Z}\\ z=\frac{Z}{X+Y+Z}\end{array}---\left(3\right)$

Due to x+y+z=1, with x, y two values just can determine a color, therefore all colours in visible-range can be represented with CIE-xy chromatic diagram (Fig. 3), often kind of all corresponding chromaticity coordinate (x of color, y), all drop in the scope of horseshoe-shaped spectrum locus encirclement.In figure, S is called equal-energy white luminous point, and its chromaticity coordinate is (0.3333,0.3333), represents three kinds of primary colors mixed in equal amounts; C point is a color chromaticity coordinates point, and coordinate is (x, y), and the extended line of SC hands over spectrum locus (i.e. monochromatic track) in D point, and the wavelength of D point spectrum colour is exactly the predominant wavelength of C point color.Dominant wavelength is the important indicator of color quantizing, and visible light colors represents with 1 nanometer intervals by it from 380nm to 700nm, can represent a kind of tone of color with concrete wavelength form.

Computing unit 82 is for calculating the second chromaticity coordinate of the predominant wavelength of the first chromaticity coordinate institute characterizing color;

If the first chromaticity coordinate is C point coordinate in Fig. 3, then the second chromaticity coordinate of the predominant wavelength of the first chromaticity coordinate institute characterizing color is D point coordinate.

First determining unit 83 is for determining the first distance between the equal-energy white point in the first chromaticity coordinate and chromatic diagram, and the second distance between equal-energy white point in the second chromaticity coordinate and chromatic diagram;

Second determining unit 84 is for being defined as the saturation degree of water surface point to be identified by the first distance and the ratio of second distance.

Figure 3 shows that example, the ratio SC/SD of the saturation degree of C point to be C point to distance SC and the D of S point the put distance SD of S point.

Optionally, a kind of structural representation of the computing unit 82 that the embodiment of the present invention provides as shown in Figure 9, can comprise:

Computation subunit 91, first determines that subelement 93 determined by subelement 92 and second; Wherein,

Computation subunit 91 for calculating with the equal-energy white point in chromatic diagram for starting point, the angle of preset coordinate axle in the vector being terminal with the first chromaticity coordinate and chromatic diagram;

For ease of describing, as shown in Figure 3, a new rectangular coordinate system o'x'y' is set up in chromatic diagram, wherein, coordinate origin o' is arranged in the equal-energy white point S of chromatic diagram, x' axle is with chromatic diagram y-axis is parallel and direction is consistent, and y' axle is with x-axis in chromatic diagram is parallel and direction is consistent, and chromatic diagram is divided into four quadrants by x' axle meet at o' point vertical with y' axle.

The chromaticity coordinate (x, y) of each nano wave length of chromatic diagram object-line (i.e. spectrum locus) is converted to the coordinate (x', y') under new coordinate system, conversion formula is:

x'＝y-0.3333

y'＝x-0.3333

(4)

In o'x'y' coordinate system, suppose that vector (x', y') and x' positive axis angle are α, then angle α computing formula is: α=ARCTAN2 (y', x')=ARCTAN2 (x-0.3333, y-0.3333) (4)

Wherein, ARCTAN2 function representation bivariate arctan function, the codomain of bivariate tan is (-180 °, 180 °), i.e. vector (x', y') bear axle from x' and be rotated counterclockwise the process bearing axle through x' positive axis again to x', arctan function changes to-180 ° from-180 °.

Because the x' axle in o'x'y' coordinate system is parallel with the y-axis in chromatic diagram, therefore, vector (x', y') and x' positive axis angle equal the angle of the y-axis in vector (x', y') and chromatic diagram.

After coordinate conversion, ARCTAN2 function can make α angle increase progressively along with dominant wavelength, namely corresponding from 380nm to 700nm α contends greatly cumulative, like this, the α angle look-up table of an incremental order corresponding from 380nm to 700nm can be set up, i.e. the mapping table of angle and dominant wavelength.

In the embodiment of the present invention, also wave spectrum chromaticity coordinate each in the spectrum locus of CIE-xy chromatic diagram is set up the look-up table of a corresponding spectral chromaticity coordinates of wavelength from 380nm to 700nm, i.e. the mapping table of dominant wavelength and chromaticity coordinate.

First determines that subelement 92 is for the corresponding relation according to preset angle and dominant wavelength, determines the dominant wavelength corresponding with angle;

Concrete, if there is not determined angle value in the corresponding relation of preset angle and dominant wavelength, then the dominant wavelength selecting the angle nearest with determined angle corresponding is the dominant wavelength corresponding with determined angle.Such as, suppose that determined angle α is 6 degree, and in the corresponding relation of preset angle and dominant wavelength, what 558nm was corresponding is 5.51 degree.What 559nm was corresponding is 7.01 degree, and 6 degree from 5.51 degree more close to, therefore determine that the dominant wavelength corresponding with determined angle is 558nm.

Second determines that subelement 93 is for the corresponding relation according to preset dominant wavelength and chromaticity coordinate, determines the chromaticity coordinate corresponding with determined dominant wavelength.

Those of ordinary skill in the art can recognize, in conjunction with unit and the algorithm steps of each example of embodiment disclosed herein description, can realize with the combination of electronic hardware or computer software and electronic hardware.These functions perform with hardware or software mode actually, depend on application-specific and the design constraint of technical scheme.Professional and technical personnel can use distinct methods to realize described function to each specifically should being used for, but this realization should not thought and exceeds scope of the present invention.

Those skilled in the art can be well understood to, for convenience and simplicity of description, the specific works process of the system of foregoing description (if existence), device and unit, with reference to the corresponding process in preceding method embodiment, can not repeat them here.

In several embodiments that the application provides, should be understood that, disclosed system (if existence), apparatus and method, can realize by another way.Such as, device embodiment described above is only schematic, such as, the division of described unit, be only a kind of logic function to divide, actual can have other dividing mode when realizing, such as multiple unit or assembly can in conjunction with or another system can be integrated into, or some features can be ignored, or do not perform.Another point, shown or discussed coupling each other or direct-coupling or communication connection can be by some interfaces, and the indirect coupling of device or unit or communication connection can be electrical, machinery or other form.

The described unit illustrated as separating component or can may not be and physically separates, and the parts as unit display can be or may not be physical location, namely can be positioned at a place, or also can be distributed in multiple network element.Some or all of unit wherein can be selected according to the actual needs to realize the object of the present embodiment scheme.

In addition, each functional unit in each embodiment of the present invention can be integrated in a processing unit, also can be that the independent physics of unit exists, also can two or more unit in a unit integrated.

If described function using the form of SFU software functional unit realize and as independently production marketing or use time, can be stored in a computer read/write memory medium.Based on such understanding, the part of the part that technical scheme of the present invention contributes to prior art in essence in other words or this technical scheme can embody with the form of software product, this computer software product is stored in a storage medium, comprising some instructions in order to make a computer equipment (can be personal computer, server, or the network equipment etc.) perform all or part of step of method described in each embodiment of the present invention.And aforesaid storage medium comprises: USB flash disk, portable hard drive, ROM (read-only memory) (ROM, Read-OnlyMemory), random access memory (RAM, RandomAccessMemory), magnetic disc or CD etc. various can be program code stored medium.

To the above-mentioned explanation of the disclosed embodiments, professional and technical personnel in the field are realized or uses the present invention.To be apparent for those skilled in the art to the multiple amendment of these embodiments, General Principle as defined herein can without departing from the spirit or scope of the present invention, realize in other embodiments.Therefore, the present invention can not be restricted to these embodiments shown in this article, but will meet the widest scope consistent with principle disclosed herein and features of novelty.

Claims (10)

1. a city black and odorous water remote sensing recognition method, is characterized in that, comprising:

Obtain the remotely-sensed data of water surface point to be identified;

The spectral tristimulus value of described water surface point to be identified is calculated based on described remotely-sensed data;

The saturation degree of described water surface point to be identified is calculated based on described spectral tristimulus value;

If described saturation degree is less than predetermined threshold value, determine that described water surface point to be identified is black and odorous water.

2. method according to claim 1, is characterized in that, the remotely-sensed data of described water surface point to be identified comprises: the tristimulus values of corresponding pixel to be identified with the described water surface in water surface remote sensing images;

The described spectral tristimulus value calculating described water surface point to be identified based on described remotely-sensed data comprises:

Described tristimulus values is converted to spectral tristimulus value by the transformational relation according to tristimulus values and tristimulus values.

3. method according to claim 1, is characterized in that, the remotely-sensed data of described water surface point to be identified comprises: the actual measurement Remote Sensing Reflectance of each wave band of described water surface point to be identified;

The described spectral tristimulus value calculating described water surface point to be identified based on described remotely-sensed data comprises:

The actual measurement Remote Sensing Reflectance of each wave band described is converted to satellite band equivalent reflectivity;

The corresponding relation of foundation equivalent reflectivity and wave band, obtains the tristimulus values corresponding with trichromatic wave band of described water surface point to be identified;

Described tristimulus values is converted to spectral tristimulus value by the transformational relation according to tristimulus values and tristimulus values.

4. method according to claim 1, is characterized in that, the described saturation degree calculating described water surface point to be identified based on described spectral tristimulus value comprises:

Described spectral tristimulus value is converted to the first chromaticity coordinate of described water surface point to be identified;

Calculate the second chromaticity coordinate of the predominant wavelength of described first chromaticity coordinate institute characterizing color;

Determine the first distance between the equal-energy white point in described first chromaticity coordinate and chromatic diagram, and the second distance between equal-energy white point in described second chromaticity coordinate and chromatic diagram;

Described first distance and the ratio of described second distance are defined as the saturation degree of described water surface point to be identified.

5. method according to claim 4, is characterized in that, the second chromaticity coordinate that the predominant wavelength of the described first chromaticity coordinate institute characterizing color of described calculating is corresponding comprises:

Calculate with the equal-energy white point in chromatic diagram for starting point, the angle of preset coordinate axle in the vector being terminal with described first chromaticity coordinate and described chromatic diagram;

According to the corresponding relation of preset angle and dominant wavelength, determine the dominant wavelength corresponding with described angle;

According to the corresponding relation of preset dominant wavelength and chromaticity coordinate, determine the chromaticity coordinate corresponding with determined dominant wavelength.

6. a city black and odorous water remote sensing recognition device, is characterized in that, comprising:

Acquisition module, for obtaining the remotely-sensed data of water surface point to be identified;

First computing module, for calculating the spectral tristimulus value of described water surface point to be identified based on described remotely-sensed data;

Second computing module, for calculating the saturation degree of described water surface point to be identified based on described spectral tristimulus value;

Determination module, if be less than predetermined threshold value for described saturation degree, determines that described water surface point to be identified is black and odorous water.

7. device according to claim 6, is characterized in that, the remotely-sensed data of described water surface point to be identified comprises: the tristimulus values of corresponding pixel to be identified with the described water surface in water surface remote sensing images;

Described first computing module comprises:

First converting unit, for the transformational relation according to tristimulus values and tristimulus values, is converted to spectral tristimulus value by described tristimulus values.

8. device according to claim 6, is characterized in that, the remotely-sensed data of described water surface point to be identified comprises: the actual measurement Remote Sensing Reflectance of each wave band of described water surface point to be identified;

Described first computing module comprises:

Second converting unit, for being converted to satellite band equivalent reflectivity by the actual measurement Remote Sensing Reflectance of each wave band described;

Acquiring unit, for the corresponding relation according to equivalent reflectivity and wave band, obtains the tristimulus values corresponding with trichromatic wave band of described water surface point to be identified;

3rd converting unit, for being converted to spectral tristimulus value according to the transformational relation of tristimulus values and tristimulus values by described tristimulus values.

9. device according to claim 6, is characterized in that, described second computing module comprises:

4th converting unit, for being converted to the first chromaticity coordinate of described water surface point to be identified by described spectral tristimulus value;

Computing unit, for calculating the second chromaticity coordinate of the predominant wavelength of described first chromaticity coordinate institute characterizing color;

First determining unit, for determining the first distance between the equal-energy white point in described first chromaticity coordinate and chromatic diagram, and the second distance between equal-energy white point in described second chromaticity coordinate and chromatic diagram;

Second determining unit, for being defined as the saturation degree of described water surface point to be identified by described first distance and the ratio of described second distance.

10. device according to claim 9, is characterized in that, described computing unit comprises:

Computation subunit, for calculating with the equal-energy white point in chromatic diagram for starting point, the angle of preset coordinate axle in the vector being terminal with described first chromaticity coordinate and described chromatic diagram;

First determines subelement, for the corresponding relation according to preset angle and dominant wavelength, determines the dominant wavelength corresponding with described angle;

Second determines subelement, for the corresponding relation according to preset dominant wavelength and chromaticity coordinate, determines the chromaticity coordinate corresponding with determined dominant wavelength.