CN103413136B - A kind of detection method of infrared image mesohigh line - Google Patents

Abstract

The present invention relates to the detection method of a kind of infrared image mesohigh line, first the gradient of infrared image is calculated, carry out region growth, obtain the candidate region of high-voltage line, ridge detection method based on image second order derivative is used to obtain high-voltage line pixel in candidate region, high-voltage line pixel is attached and screens according to Freeman chain code, the high-voltage line finally detected.Compared with prior art, the present invention is not to the linear character using Hough transform to extract high-voltage line, but the classical lines detection methods such as region growth, ridge detection and Freeman chain code that fully utilize are to realize the detection of high-voltage line, the present invention can quickly detect the high-voltage line in infrared image, location high-voltage line can be arrived to sub-pixel precision, positioning precision is high, can effectively remove the impact of background noise in infrared image, foreign material, and robustness is good.

Description

A kind of detection method of infrared image mesohigh line

Technical field

The invention belongs to infrared image processing technical field, be specifically related to the detection side of a kind of infrared image mesohigh line Method.

Background technology

In the last few years, the using value of helicopter improves constantly, and function and range constantly expand.In the face of more and more multiple Miscellaneous environment, nap of the earth flight has become various countries' aircraft conventional technique.And during helicopter super low altitude flight, the wire such as high-voltage line barrier Thing is hindered but to be difficult to detect.It is reported, the reason that helicopter has an accident almost half be that collision high-pressure line barrier causes. As can be seen here, the detection technique of research high-voltage line has critically important realistic meaning.

High-voltage line has the temperature characteristic apparently higher than surrounding, has brightness clearly special in infrared image Levy.Therefore, utilizing infrared imaging device can reach to detect the purpose of high-voltage line, initially, foreign military force i.e. utilizes infrared imaging Instrument is as high-voltage line detecting devices, but is not equipped with respective image processing system, but directly uses crew's naked eyes to see Examine mode.Owing to human eye is limited to the observation ability of obstruction, operating distance is the nearest, it is impossible to provide for helicopter pilot The enough response time.

Chinese Patent Application No. 201210376272.2, describes one and " automatically identifies aerial high-voltage from infrared image The method of line ", core concept is to utilize random Hough transformation (RHT) method to realize detection to high-voltage line pixel, the method without Method avoids Hough transform to calculate complexity, the shortcoming that parameter is many, processes the infrared image that background is complicated, easily can cause substantial amounts of Flase drop.

Summary of the invention

Solve the technical problem that

In place of the deficiencies in the prior art, the present invention proposes the detection method of a kind of infrared image mesohigh line.

Technical scheme

The detection method of a kind of infrared image mesohigh line, it is characterised in that step is as follows:

Step 1: calculate gradient magnitude and the direction of infrared image；Direction according to gradient carries out region growth, obtains height Line ball candidate region；

Step 2: in high-voltage line candidate region, uses ridge detection method based on image second order derivative, obtains high pressure Line pixel；

Step 3: high-voltage line pixel be attached and screen according to Freeman chain code, finally being detected High-voltage line.

Described step 1 carries out region and increases that to obtain the step of high-voltage line candidate region as follows:

Step a: use the gradient of Sobel operator 3 × 3 formwork calculation image each pixel of I, gradient magnitude and deflection For: Wherein G_i,G_jHorizontal and vertical component for pixel gradient G；

Step b: according to the size of each pixel gradient, the pixel p choosing Grad maximum carries out region as starting point Increase, if starting pixel gradient direction angle is θ_pIf, neighborhood territory pixel gradient angle θ of pixel p_pnWith θ_pAbsolute difference little In 2 π/k(k=16), then this pixel is joined in the R of high-voltage line candidate region, the deflection in region is updated to simultaneouslyWhen repeating this process until not having new pixel to increase in region, this region R increases Growth process terminates, and then starts next starting point, until infrared image does not has as the pixel of starting point, and to answer Ensureing that all of pixel is at most accessed once, the pixel accessed can not be accessed again, will eventually get a series of High-voltage line candidate region { R₁,R₂,...R_m}。

Described step 2 uses ridge detection method based on image second order derivative, obtains the step of high-voltage line pixel such as Under:

Step a: to each pixel in infrared image I (x, y) carries out Gaussian convolution computing, obtain corresponding single order, Second order directional is:

I_x=g_σ(y)g'_σ(x)*I(x,y)I_y=g'_σ(y)g_σ(x)*I(x,y)

I_xx=g_σ(y)g''_σ(x)*I(x,y)I_xy=g'_σ(y)g'_σ(x)*I(x,y)I_yy=g''_σ(y)g_σ(x)*I(x,y)

Wherein, $g_{\mathrm{\σ}}\left(x\right)=\frac{1}{\sqrt{2\mathrm{\π}}\mathrm{\σ}}{e}^{-\frac{x^2}{{2\mathrm{\σ}}^2}},$ $g_{\mathrm{\σ}}^{\′}\left(x\right)=\frac{-x}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^3}{e}^{-\frac{x^2}{{2\mathrm{\σ}}^2}},$ $g_{\mathrm{\σ}}^{\′\′}\left(x\right)=\frac{x^2-{\mathrm{\σ}}^2}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^5}{e}^{-\frac{x^2}{{2\mathrm{\σ}}^2}}$

$g_{\mathrm{\σ}}\left(y\right)=\frac{1}{\sqrt{2\mathrm{\π}}\mathrm{\σ}}{e}^{-\frac{y^2}{{2\mathrm{\σ}}^2}},$ $g_{\mathrm{\σ}}^{\′}\left(y\right)=\frac{-x}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^3}{e}^{-\frac{y^2}{{2\mathrm{\σ}}^2}},$ $g_{\mathrm{\σ}}^{\′\′}\left(y\right)=\frac{x^2-{\mathrm{\σ}}^2}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^5}{e}^{-\frac{y^2}{{2\mathrm{\σ}}^2}}$

Step b: calculate each pixel in infrared image high-voltage line candidate region (x, y) corresponding Hessian matrix $H(x,y)=\left[\begin{array}{cc}{I}_{\mathrm{xx}}& I_{\mathrm{xy}}\\ I_{\mathrm{xy}}& I_{\mathrm{yy}}\end{array}\right]$ Eigenvalue, obtain maximum eigenvalue characteristic of correspondence vector (n_x,n_y).Along (n_x,n_y) direction Calculate the location of pixels (p making first directional derivative be zero_x,p_y):

$(p_x,p_y)=(-\frac{I_x{n}_x^2+I_x{n}_x{n}_y}{I_{\mathrm{xx}}{n}_x^2+2I_{\mathrm{xy}}{n}_x{n}_y+I_{\mathrm{yy}}{n}_y^2},-\frac{I_y{n}_y^2+I_y{n}_x{n}_y}{I_{\mathrm{xx}}{n}_x^2+2I_{\mathrm{xy}}{n}_x{n}_y+I_{\mathrm{yy}}{n}_y^2})$

If (p_x,p_y) ∈ ([-0.5,0.5], [-0.5,0.5]) and (x y) waits at same high-voltage line with pixel In favored area, then this pixel is high-voltage line pixel.

The high-voltage line pixel of described step 3 is attached method: choose the high-voltage line picture that Second order directional is maximum Vegetarian refreshments p_startFor the starting point of high-voltage line, neighborhood is found next high-voltage line pixel p around_nextConnect into high-voltage line, This pixel should make d+ β obtain minima, and wherein d represents the distance between the two high-voltage line pixel, and β represents the two High-voltage line pixel (n_x,n_y) differential seat angle in direction.High-voltage line is connected into according to this rule recurrence.

The Freeman chain code screening of described step 3 is: if representing the chain of horizontal direction in high-voltage line Freeman chain code Code accounts for the ratio of chain code sum and is less than 0.6, then remove this high-voltage line, otherwise retain this high-voltage line.Through screening, finally examined The high-voltage line surveyed.

Beneficial effect

The detection method of a kind of infrared image mesohigh line that the present invention proposes, first calculates the gradient of infrared image, enters Row region increases, and obtains the candidate region of high-voltage line, uses ridge detection side based on image second order derivative in candidate region Method obtains high-voltage line pixel, is attached high-voltage line pixel and screens according to Freeman chain code, finally being examined The high-voltage line surveyed.

Compared with prior art, employing Hough transform is not extracted the linear character of high-voltage line by the present invention, but The classical lines detection methods such as region growth, ridge detection and Freeman chain code that fully utilize are to realize the inspection of high-voltage line Surveying, the present invention can quickly detect the high-voltage line in infrared image, can arrive location high-voltage line to sub-pixel precision, positioning precision Height, can effectively remove the impact of background noise in infrared image, foreign material, and robustness is good.

Accompanying drawing explanation

Fig. 1 is flow chart of the present invention；

Fig. 2 is infrared image；

Fig. 3 is the high-voltage line candidate region result figure after Fig. 2 carries out region growth；

Fig. 4 is the result figure of high-voltage line detection.

Detailed description of the invention

In conjunction with embodiment, accompanying drawing, the invention will be further described:

Embodiment of the present invention step is as follows:

Step 1: calculate the gradient of infrared image, carries out region growth and obtains high-voltage line candidate region, particularly as follows: initially with The gradient of Sobel operator 3 × 3 formwork calculation infrared image each pixel of I, gradient magnitude and deflection be: Wherein G_i,G_jHorizontal and vertical component for pixel gradient G；Then big according to each pixel gradient Little, the pixel p choosing Grad maximum carries out region growth as starting point, if starting pixel gradient direction angle is θ_p, as Really neighborhood territory pixel gradient angle θ of pixel p_pnWith θ_pAbsolute difference less than 2 π/k(k=16), then this pixel is joined high pressure In the R of line candidate region, the deflection in region is updated to simultaneouslyRepeat this process straight When increasing in region to not having new pixel, this region R propagation process terminates, and then starts next starting point, until red Outer image do not have can be as the pixel of starting point till, and should ensure that all of pixel is at most accessed once, accessed Pixel can not be accessed again.Will eventually get a series of high-voltage line candidate region { R₁,R₂,...R_m}。

Step 2: in high-voltage line candidate region, uses ridge detection method based on image second order derivative, obtains high pressure Line pixel, particularly as follows: first to each pixel in infrared image I, (x, y) carries out Gaussian convolution computing, obtains corresponding Single order, Second order directional be:

I_x=g_σ(y)g'_σ(x)*I(x,y)I_y=g'_σ(y)g_σ(x)*I(x,y)

I_xx=g_σ(y)g''_σ(x)*I(x,y)I_xy=g'_σ(y)g'_σ(x)*I(x,y)I_yy=g''_σ(y)g_σ(x)*I(x,y)

Wherein, $g_{\mathrm{\σ}}\left(x\right)=\frac{1}{\sqrt{2\mathrm{\π}}\mathrm{\σ}}{e}^{-\frac{x^2}{{2\mathrm{\σ}}^2}},$ $g_{\mathrm{\σ}}^{\′}\left(x\right)=\frac{-x}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^3}{e}^{-\frac{x^2}{{2\mathrm{\σ}}^2}},$ $g_{\mathrm{\σ}}^{\′\′}\left(x\right)=\frac{x^2-{\mathrm{\σ}}^2}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^5}{e}^{-\frac{x^2}{{2\mathrm{\σ}}^2}}$

$g_{\mathrm{\σ}}\left(y\right)=\frac{1}{\sqrt{2\mathrm{\π}}\mathrm{\σ}}{e}^{-\frac{y^2}{{2\mathrm{\σ}}^2}},$ $g_{\mathrm{\σ}}^{\′}\left(y\right)=\frac{-x}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^3}{e}^{-\frac{y^2}{{2\mathrm{\σ}}^2}},$ $g_{\mathrm{\σ}}^{\′\′}\left(y\right)=\frac{x^2-{\mathrm{\σ}}^2}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^5}{e}^{-\frac{y^2}{{2\mathrm{\σ}}^2}}$

Then each pixel in infrared image high-voltage line candidate region (x, y) corresponding Hessian matrix are calculated $H(x,y)=\left[\begin{array}{cc}{I}_{\mathrm{xx}}& I_{\mathrm{xy}}\\ I_{\mathrm{xy}}& I_{\mathrm{yy}}\end{array}\right]$ Eigenvalue, obtain maximum eigenvalue characteristic of correspondence vector (n_x,n_y).Along (n_x,n_y) direction Calculate the location of pixels (p making first directional derivative be zero_x,p_y):

$(p_x,p_y)=(-\frac{I_x{n}_x^2+I_x{n}_x{n}_y}{I_{\mathrm{xx}}{n}_x^2+2I_{\mathrm{xy}}{n}_x{n}_y+I_{\mathrm{yy}}{n}_y^2},-\frac{I_y{n}_y^2+I_y{n}_x{n}_y}{I_{\mathrm{xx}}{n}_x^2+2I_{\mathrm{xy}}{n}_x{n}_y+I_{\mathrm{yy}}{n}_y^2}),$ If (p_x,p_y)∈([-0.5,0.5],[- 0.5,0.5]) and (x, y) in same high-voltage line candidate region, then this pixel is high-voltage line pixel with pixel.

Step 3: high-voltage line pixel is attached and screens according to Freeman chain code, it is achieved the essence of high-voltage line First really detection and localization, particularly as follows: choose the high-voltage line pixel p that Second order directional is maximum_startFor the starting point of high-voltage line, Neighborhood is found next high-voltage line pixel p around_nextConnecting into high-voltage line, this pixel should make d+ β obtain minimum Value, wherein d represents the distance between the two high-voltage line pixel, and β represents the two high-voltage line pixel (n_x,n_y) direction Differential seat angle.Connect into high-voltage line according to this rule recurrence, during connecting, the high-voltage line connected is carried out simultaneously Freeman chain code encodes.Then according to high-voltage line Freeman chain code, high-voltage line is screened, if high-voltage line Freeman chain Represent the chain code of horizontal direction in Ma and account for the ratio of chain code sum less than 0.6, then remove this high-voltage line, otherwise retain this high pressure Line.Through screening, the high-voltage line finally detected.

Specific embodiment:

Hardware environment for implementing is: Intel Duo 2 double-core 2.93G computer, 2.0GB internal memory, 512M video card, fortune The software environment of row is: Microsoft Visual Studio2008, Windows XP.We use Microsoft Visual Studio2008 software achieves the method that the present invention proposes.Infrared image size is 582*458.

1, the gradient of the infrared image in calculating Fig. 2, carries out region growth and obtains high-voltage line candidate region, particularly as follows: first First using the gradient of Sobel operator 3 × 3 formwork calculation infrared image each pixel of I, gradient magnitude and deflection be: Wherein G_i,G_jHorizontal and vertical component for pixel gradient G；Then according to each The size of individual pixel gradient, the pixel p choosing Grad maximum carries out region growth as starting point, if starting pixel gradient Deflection is θ_pIf, neighborhood territory pixel gradient angle θ of pixel p_pnWith θ_pAbsolute difference less than 2 π/k(k=16), then should Pixel joins in the R of high-voltage line candidate region, is updated to by the deflection in region simultaneously When repeating this process until not having new pixel to increase in region, this region R propagation process terminates, and then starts the next one Starting point, until infrared image does not has as the pixel of starting point, and to should ensure that all of pixel is the most interviewed Asking once, the pixel accessed can not be accessed again.Will eventually get a series of high-voltage line candidate region { R₁,R₂, ...R_m, as shown in Figure 3.

2, in high-voltage line candidate region, use ridge detection method based on image second order derivative, obtain high-voltage line picture Vegetarian refreshments, particularly as follows: first to each pixel in the infrared image in Fig. 1, (x y) carries out Gaussian convolution computing, obtains phase Single order, the Second order directional answered be:

I_x=g_σ(y)g'_σ(x)*I(x,y)I_y=g'_σ(y)g_σ(x)*I(x,y)

I_xx=g_σ(y)g''_σ(x)*I(x,y)I_xy=g'_σ(y)g'_σ(x)*I(x,y)I_yy=g''_σ(y)g_σ(x)*I(x,y)

Wherein, $g_{\mathrm{\σ}}\left(x\right)=\frac{1}{\sqrt{2\mathrm{\π}}\mathrm{\σ}}{e}^{-\frac{x^2}{{2\mathrm{\σ}}^2}},$ $g_{\mathrm{\σ}}^{\′}\left(x\right)=\frac{-x}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^3}{e}^{-\frac{x^2}{{2\mathrm{\σ}}^2}},$ $g_{\mathrm{\σ}}^{\′\′}\left(x\right)=\frac{x^2-{\mathrm{\σ}}^2}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^5}{e}^{-\frac{x^2}{{2\mathrm{\σ}}^2}}$

$g_{\mathrm{\σ}}\left(y\right)=\frac{1}{\sqrt{2\mathrm{\π}}\mathrm{\σ}}{e}^{-\frac{y^2}{{2\mathrm{\σ}}^2}},$ $g_{\mathrm{\σ}}^{\′}\left(y\right)=\frac{-x}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^3}{e}^{-\frac{y^2}{{2\mathrm{\σ}}^2}},$ $g_{\mathrm{\σ}}^{\′\′}\left(y\right)=\frac{x^2-{\mathrm{\σ}}^2}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^5}{e}^{-\frac{y^2}{{2\mathrm{\σ}}^2}}$

Then each pixel in infrared image high-voltage line candidate region (x, y) corresponding Hessian matrix are calculated $H(x,y)=\left[\begin{array}{cc}{I}_{\mathrm{xx}}& I_{\mathrm{xy}}\\ I_{\mathrm{xy}}& I_{\mathrm{yy}}\end{array}\right]$ Eigenvalue, obtain maximum eigenvalue characteristic of correspondence vector (n_x,n_y).Along (n_x,n_y) direction Calculate the location of pixels (p making first directional derivative be zero_x,p_y):

$(p_x,p_y)=(-\frac{I_x{n}_x^2+I_x{n}_x{n}_y}{I_{\mathrm{xx}}{n}_x^2+2I_{\mathrm{xy}}{n}_x{n}_y+I_{\mathrm{yy}}{n}_y^2},-\frac{I_y{n}_y^2+I_y{n}_x{n}_y}{I_{\mathrm{xx}}{n}_x^2+2I_{\mathrm{xy}}{n}_x{n}_y+I_{\mathrm{yy}}{n}_y^2}),$ If (p_x,p_y)∈([-0.5,0.5],[- 0.5,0.5]) and (x, y) in same high-voltage line candidate region, then this pixel is high-voltage line pixel with pixel.

3, high-voltage line pixel it is attached and screens according to Freeman chain code, it is achieved accurately determining of high-voltage line First position detection, particularly as follows: choose the high-voltage line pixel p that Second order directional is maximum_startFor the starting point of high-voltage line, in week Enclose and neighborhood is found next high-voltage line pixel p_nextConnecting into high-voltage line, this pixel should make d+ β obtain minima, its Middle d represents the distance between the two high-voltage line pixel, and β represents the two high-voltage line pixel (n_x,n_y) angle in direction Difference.Connect into high-voltage line according to this rule recurrence, during connecting, the high-voltage line connected is carried out Freeman chain simultaneously Code coding.Then according to high-voltage line Freeman chain code, high-voltage line is screened, if high-voltage line Freeman chain code represents The chain code of horizontal direction accounts for the ratio of chain code sum and is less than 0.6, then remove this high-voltage line, otherwise retain this high-voltage line.Through this mistake After journey screening, obtain final high-voltage line testing result, as shown in Figure 4.

Claims (4)

1. the detection method of an infrared image mesohigh line, it is characterised in that step is as follows:

Step 1: calculate gradient magnitude and the direction of infrared image；Direction according to gradient carries out region growth, obtains high-voltage line Candidate region；

Step 2: in high-voltage line candidate region, uses ridge detection method based on image second order derivative, obtains high-voltage line picture Vegetarian refreshments；

Step 3: high-voltage line pixel is attached and screens according to Freeman chain code, the high pressure finally detected Line；

Described step 2 uses ridge detection method based on image second order derivative, and the step obtaining high-voltage line pixel is as follows:

Step a: (x y) carries out Gaussian convolution computing, obtains corresponding single order, second order to each pixel in infrared image I Directional derivative is:

I_x=g_σ(y)g’_σ(x) * I (x, y) I_y=g '_σ(y)g_σ(x) * I (x, y)

I_xx=g_σ(y)g″_σ(x)*I(x,y) I_xy=g '_σ(y)g’_σ(x)*I(x,y) I_yy=g "_σ(y)g_σ(x)*I(x,y)

Wherein, $g_{\mathrm{\σ}}\left(x\right)=\frac{1}{\sqrt{2\mathrm{\π}}\mathrm{\σ}}{e}^{-\frac{x^2}{2{\mathrm{\σ}}^2}},g_{\mathrm{\σ}}^{,}\left(x\right)=\frac{-x}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^3}{e}^{-\frac{x^2}{2{\mathrm{\σ}}^2}},g_{\mathrm{\σ}}^{\′\′}\left(x\right)=\frac{x^2-{\mathrm{\σ}}^2}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^5}{e}^{-\frac{x^2}{2{\mathrm{\σ}}^2}}$

$g_{\mathrm{\σ}}\left(y\right)=\frac{1}{\sqrt{2\mathrm{\π}}\mathrm{\σ}}{e}^{-\frac{y^2}{2{\mathrm{\σ}}^2}},g_{\mathrm{\σ}}^{,}\left(y\right)=\frac{-x}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^3}{e}^{-\frac{y^2}{2{\mathrm{\σ}}^2}},g_{\mathrm{\σ}}^{\′\′}\left(y\right)=\frac{x^2-{\mathrm{\σ}}^2}{\sqrt{2\mathrm{\π}}{\mathrm{\σ}}^5}{e}^{-\frac{y^2}{2{\mathrm{\σ}}^2}}$

Step b: calculate each pixel in infrared image high-voltage line candidate region (x, y) corresponding Hessian matrix $H(x,y)=\left[\begin{array}{cc}{I}_{xx}& I_{xy}\\ I_{xy}& I_{yy}\end{array}\right]$ Eigenvalue, obtain maximum eigenvalue characteristic of correspondence vector (n_x,n_y)；Along (n_x,n_y) telegoniometer Calculate the location of pixels (p making first directional derivative be zero_x,p_y):

$(p_x,p_y)=(-\frac{I_x{n}_x^2+I_x{n}_x{n}_y}{I_{xx}{n}_x^2+2I_{xy}{n}_x{n}_y+I_{yy}{n}_y^2},-\frac{I_y{n}_y^2+I_y{n}_x{n}_y}{I_{xx}{n}_x^2+2I_{xy}{n}_x{n}_y+I_{yy}{n}_y^2})$

If (p_x,p_y) ∈ ([-0.5,0.5], [-0.5,0.5]) and (x, y) at same high-voltage line candidate regions with pixel In territory, then this pixel is high-voltage line pixel.

The detection method of infrared image mesohigh line the most according to claim 1, it is characterised in that: described step 1 carries out district The step that territory growth obtains high-voltage line candidate region is as follows:

Step a: using the gradient of Sobel operator 3 × 3 formwork calculation image each pixel of I, gradient magnitude and deflection be:Wherein G_i,G_jHorizontal and vertical component for pixel gradient G；

Step b: according to the size of each pixel gradient, the pixel p choosing Grad maximum carries out region growth as starting point, If starting pixel gradient direction angle is θ_pIf, neighborhood territory pixel gradient angle θ of pixel p_pnWith θ_pAbsolute difference less than 2 π/ K, k=16, then join this pixel in the R of high-voltage line candidate region, be updated to by the deflection in region simultaneouslyWhen repeating this process until not having new pixel to increase in region, this region R increases Growth process terminates, and then starts next starting point, until infrared image does not has as the pixel of starting point, and to answer Ensureing that all of pixel is at most accessed once, the pixel accessed can not be accessed again, will eventually get a series of High-voltage line candidate region { R₁,R₂,...R_m}。

The detection method of infrared image mesohigh line the most according to claim 1, it is characterised in that: the high pressure of described step 3 Line pixel is attached method: choose the high-voltage line pixel p that Second order directional is maximum_startInitiateing for high-voltage line Point, finds next high-voltage line pixel p around in neighborhood_nextConnecting into high-voltage line, this pixel should make d+ β obtain Little value, wherein d represents the distance between the two high-voltage line pixel, and β represents the two high-voltage line pixel (n_x,n_y) direction Differential seat angle, according to this rule recurrence connect into high-voltage line.

The detection method of infrared image mesohigh line the most according to claim 1, it is characterised in that: described step 3 The screening of Freeman chain code is: if the ratio that the chain code representing horizontal direction in high-voltage line Freeman chain code accounts for chain code sum is little In 0.6, then remove this high-voltage line, otherwise retain this high-voltage line, through screening, the high-voltage line finally detected.