CN202940888U - Full-automatic focusing device for infrared imaging equipment - Google Patents

Abstract

The utility model discloses a full-automatic focusing device for infrared imaging equipment. The device comprises an automatic focusing system for driving a focusing motor. The automatic focusing system is provided with an automatic focusing switch and a full-automatic focusing switch. The automatic focusing system comprises an FIFO buffer for buffering digital image signals, a DSP microprocessor for processing data and a communication control module in drive connection with the focusing motor, wherein the FIFO buffer, the DSP microprocessor and the communication control module are connected in sequence. The DSP microprocessor is in bidirectional communication connection with the communication control module. Focusing precision is improved by a self-designed image quality judgment method, the focusing capacity for weak targets is improved, focusing failure is greatly avoided, proper focusing time is shortened by an improved motor driven algorithm, and focusing stability is improved. By adding an intelligent mode recognition method, 'full-automatic focusing' is realized, namely, human intervention is omitted in the whole process, image characteristics of a current scene are automatically judged, and the focusing process is started.

Description

A kind of full-automatic focusing mechanism for infrared imaging device

Technical field

The utility model relates to a kind of full-automatic focusing mechanism for infrared imaging device.

Background technology

Automatically focusing is an important technology of contemporary optics imaging system, the user needs constantly to adjust lens focus to obtain imaging effect clearly with manual mode when observing different target before it occurs, due to the power of human eye identification capability, can't be adjusted to the best toward contact simultaneously.The appearance of Autofocus Technology has made up this defective, and fast, accurately drive motors is to best focusing position with automated manner for he, allows the user can facilitate, fast observation and identify target.

Current Autofocus Technology has become the standard configuration of the products such as camera, video camera, mobile phone, but in the infrared thermal imaging industry, due to its higher technical threshold, a large amount of application, not yet appear in the characteristics of the weak contrast of infrared image self, Poor information, few contour feature in addition; But, as a kind of industrial trend, listed in scientific research plan by many companies in the industry for the Autofocus Technology of infrared imaging, even as the companies such as industry bellwether's Gao De, large vertical, Ai Rui, POP all existing Related product occur, but all be in the stage of fumbling at focusing precision, focusing speed and three key performances of stability; Simultaneously, the technology that current line is studied in the industry belongs to " semi-automatic focusing " more, namely needs the user to carry out manually opened, just can carry out the processing of focusing automatically.

The utility model content

The purpose of this utility model is to provide a kind of full-automatic focusing mechanism for infrared imaging device, with solve focusing method in prior art focusing precision, focusing speed and stable aspect deficiency.

in order to realize above purpose, the technical scheme of the full-automatic focusing mechanism for infrared imaging device provided by the utility model is as follows: a kind of full-automatic focusing mechanism for infrared imaging device, this device comprises for the automatic focusing system that drives the focusing motor, described automatic focusing system is provided with automatically to focal switch with automatically to focal switch, described automatic focusing system comprises the FIFO buffer that is used for the buffer memory data image signal that connects successively, DSP microprocessor and the communication control module that is connected being connected with the focusing motor-driven for the treatment of data, described DSP microprocessor is connected with the communication control module both-way communication.

Described automatic focusing system also comprises A/D converter, and the output of described A/D converter is connected with the signal input part of FIFO buffer.

The utility model is used for the full-automatic focusing mechanism of infrared imaging device and method and has improved the focusing precision with the image quality judging method of autonomous Design, and improved focusing ability for weak target (being the low target of contrast), greatly avoided the generation of focusing failure scenarios, reduced by improvement motor-driven algorithm the required time that puts in place of focusing simultaneously, improved the stability of focusing; And on this basis, by adding the intelligent mode recognition methods, realized " full-automatic focusing ", be that whole process need not human intervention, automatic decision current scene characteristics of image also starts focus process, thereby make product not only can be used for the fields such as common infrared viewing, measurement, warning, also can conveniently be applied to IMAQ, record and analysis under unattended operation, the industries such as this security protection warning in the commercial market, forest fire protection, industrial thermometric, all there is application prospect preferably the aspects such as the plateau monitoring in military market, island warning, unmanned plane cruising.

Description of drawings

Fig. 1 is the theory diagram of the full-automatic focusing mechanism of the utility model;

Fig. 2 is the hardware elementary diagram of the utility model automatic focusing system;

Fig. 3 is the flow chart of the full-automatic focusing method of the utility model.

Embodiment

The utility model be used for infrared imaging device full-automatic focusing mechanism theory diagram as shown in Figure 1, as seen from the figure, the automatic focusing of the method is divided into two kinds of patterns: the first " focusing automatically " pattern, this pattern is opened when artificial judgment need to be focused, and each only operation flow process of once focusing of opening puts in place to focusing and stops; It two is " full-automatic focusing " patterns, real-time adaptive judgement current scene feature and automatically start the focusing flow process after opening, and whole process need not manual intervention.

Wherein, the focusing flow process that two kinds of patterns are all used is as described below: automatic focusing system is by the numeral in thermal imager Real-time Obtaining video flowing or analog image (disposal ability that possesses simultaneously two class interfaces), determine by analysis drive motors state (forward, reverse and stop), and drive motors is to change lens focus, until judge that current being as the criterion stops motor during burnt position, focuses complete.

automatic focusing mechanism of the present utility model comprises for the automatic focusing system that drives the focusing motor, automatic focusing system is provided with automatically to focal switch with automatically to focal switch, described automatic focusing system comprises the FIFO buffer that is used for the buffer memory data image signal that connects successively, DSP microprocessor and the communication control module that is connected being connected with the focusing motor-driven for the treatment of data, described DSP microprocessor is connected with the communication control module both-way communication, automatic focusing system also comprises AD converter, the output of A/D converter is connected with the signal input part of FIFO buffer, as shown in Figure 2.A/D converter is sent into buffer after being responsible for transferring the analog video stream that thermal imager is exported to digital signal, directly enters buffer if thermal imager possesses the output digital video condition, does not need A/D converter; The FIFO buffer is responsible for receiving digital signals, delivers to the DSP microprocessor after the whole frame of buffer memory; The DSP microprocessor is core processing unit, it receives the video data from buffer, process and analyze rear definite motor-driven state according to the pattern of current selection, state information is issued communication control module, and it receives " focusing automatically " and " full-automatic focusing " the mode switch order from communication control module simultaneously; Communication Control receives one side according to carrying out motor-driven from the motor drive signal of microprocessor, receives on the one hand outside mode switch order, and issues microprocessor.

Be illustrated in figure 3 as the flow chart that the utility model is used for the full-automatic focusing method of infrared imaging device, in focus process, motor back and forth mobile at most three times until stop, concrete focus process is referring to following process:

(1) start focusing, make it be in initial state: to drive motors nearby, in process, image is carried out feature extraction, and carry out the movement tendency judgement according to extracting feature, obtain three kinds of judged results: when occurring difference in process and reach 4 times greater than 200 number of times continuously, think and the current climbing phase that is in change the state three condition over to; 20 sub-eigenvalues are added up, when wherein be in＜5～20 number less than wherein be in＜-5～-20 the time, think that focusing anisotropy, image just are being tending towards fuzzy, change the state two-state over to; When moving step length surpasses maximum step-length and limits, think to arrive the burnt journey rightmost side, change state two over to;

(2) state two: drive motors continues at a distance, in process, image is carried out feature extraction, and carry out the movement tendency judgement according to extracting feature, obtain two kinds of judged results: when occurring difference in process and reach 4 times greater than 200 number of times continuously, think and the current climbing phase that is in change the state three condition over to; When moving step length surpasses maximum step-length and limits, think to arrive the leftmost side, but image focus unsuccessfully without obvious focus target, stop motor, and stop automatic focusing;

(3) state three: in process, image is carried out feature extraction, and carries out the movement tendency judgement according to extracting feature, if any continuous 2 differences＜-50～50 between, think and just crossed overall summit this moment, get the hang of four;

(4) state four: drive motors stops motor after the predetermined step-length of opposite direction motion of laststate motion, and stops automatic focusing.

After opening " full-automatic focusing " pattern, carry out in real time the state judgement, after requiring, the satisfied focusing of its result enters automatic focusing process flow process as above, stop automatically as follows to defocused concrete treatment step:

(1) keeping track of history state: preserve at that time image and characteristic parameter when the last time when focusing stops automatically;

(2) feature extraction: the operating thermal imager image of Real-time Collection, the computed image characteristic parameter, its formula is as follows:

$V=\frac{\sqrt{\mathrm{\Σ}{(i(x+1,y)-i(x,y))}^2}}{n}|i(x+1)-i\left(x\right)|>T$

Wherein, i is the gray value of certain location of pixels on image, if and only if its with the absolute value of the difference of gray value following closely during greater than threshold value T, this value just can add in calculating, n is calculated number of pixels sum, this function is used for edge sharpness (the being definition) situation of Description Image, is worth greatlyr, and the key diagram picture is more clear.

(3) feature judgement: image and history image that characteristic extraction step is obtained mate according to similarity principle, obtain its Similarity Parameter; The more current characteristic parameter that obtains and history feature parameter obtain its difference,, start focusing, otherwise enter feature extraction next time during all over predetermined threshold value at Similarity Parameter and characteristic parameter.

Claims (2)

1. full-automatic focusing mechanism that is used for infrared imaging device, it is characterized in that: this device comprises for the automatic focusing system that drives the focusing motor, described automatic focusing system is provided with automatically to focal switch with automatically to focal switch, described automatic focusing system comprises successively the FIFO buffer that is used for the buffer memory data image signal that connects, for the treatment of the DSP microprocessor of data be connected the communication control module that is connected with the motor-driven of focusing, described DSP microprocessor is connected with the communication control module both-way communication.

2. the full-automatic focusing mechanism for infrared imaging device according to claim 1, it is characterized in that: described automatic focusing system also comprises A/D converter, the output of described A/D converter is connected with the signal input part of FIFO buffer.

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