WO2012122788A1

WO2012122788A1 - Method for obtaining image correction coefficient, and method and system for correcting non-uniform image

Info

Publication number: WO2012122788A1
Application number: PCT/CN2011/080268
Authority: WO
Inventors: 姜正中
Original assignee: 浙江兆晟科技有限公司
Priority date: 2011-03-14
Filing date: 2011-09-28
Publication date: 2012-09-20
Also published as: CN102176742A; CN102176742B

Abstract

The present invention relates to a method for obtaining an image correction coefficient, and a method and system for correcting a non-uniform image. At least two groups of sensor units in a sensor array are used; a plurality of background images of the sensor array at different working temperatures are collected; pixels of a pre-corrected image outputted by the sensor array are correspondingly grouped according to the grouping of the sensor units in the sensor array; each pixel value of the pre-corrected image is obtained by group; the average value of pixel values in each group is calculated; in the grouping of the pre-corrected image, a correction coefficient for the current background is calculated under the condition that the sum of squares of the differences of the average values of each two groups of pixel values of the corrected image is minimal. According to the method for obtaining an image correction coefficient and the method and system for correcting a non-uniform image in the present invention, in comparison with the conventional prior art, the stopper need not be set as zero. At the same time, the calculation of the differences of adjacent pixels need not be emphasized, the requirement on the position is not high, and the calculation method is simple and convenient.

Description

Method for acquiring image correction coefficient, method and system for non-uniform image correction

The present invention relates to an image acquisition coefficient acquisition method, a non-uniform image correction method and system, and more particularly to an image acquisition coefficient acquisition method, a non-uniform image correction method, and a system in infrared imaging. Background technique

With the development of infrared technology, infrared imaging has become an important technology of imaging systems. The prior art usually uses sensor arrays for infrared imaging. Therefore, the infrared focal plane sensor array imaging system is the core component of the infrared imaging system. At present, infrared imaging systems are widely used in civil fields such as night vision, marine rescue, astronomy, industrial heat detection and medicine. However, due to manufacturing materials, processes, and working conditions, infrared focal plane sensor array imaging generally has non-uniformity problems, which seriously affects image quality. In the prior art, for the technique of solving a non-uniform image, a blank is usually used to obtain a background image under current work, so that it is necessary to temporarily intervene in the output image and interrupt the observation process. At the same time, during the use of the flap, the flap is out of order due to movement or vibration of the machine, so that it cannot be observed. In addition, the use of the blank also increases power consumption, increases the size of the instrument, and brings great inconvenience to the use.

With the development of computer technology, the correction trend for non-uniform images is corrected by computer technology. The key to the computer calibration technique lies in the acquisition of the correction parameters. The acquisition of the correction parameters mainly depends on the acquisition of the correction coefficients, and the correction of the correction parameters is used to achieve the correction of the non-uniform image. British patent

(GB 2445254B) discloses a non-uniform image correction method, the technical key of which is to obtain a correction coefficient by using a condition that satisfies the minimum square sum of the difference between the output results of adjacent sensor units, and then obtain a correction parameter by correcting the coefficient. This method requires a high number of images to be collected, and at the same time, strict requirements are placed on the position of the sensor unit. Therefore, the method implementation is complicated. Summary of the invention

The technical problem to be solved by the present invention is to provide an acquisition method of a non-uniform image correction coefficient, an image correction method and a system, and overcome the technical problem that the non-uniform image correction process in the prior art has high requirements on the system and the method is complicated.

The technical solution of the present invention is: providing a method for acquiring a non-uniform image correction coefficient, the figure The sensor array includes a plurality of sensor units, the one sensor unit outputs a pixel value, and the sensor units in the sensor array are at least two groups, and the plurality of sensor arrays are collected under different operating temperature conditions. a background image, the background image is grouped according to a grouping manner of the sensor units in the sensor array, and the method for acquiring the image correction coefficient includes the following steps:

Grouping the pre-corrected images: grouping pixels of the pre-corrected image output by the sensor array according to grouping of sensor units in the sensor array;

Calculating a correction coefficient of the current background: acquiring, by the group, each pixel value of the pre-corrected image, calculating an average value of the pixel values in the groups, and in the grouping of the pre-corrected image, satisfying each two sets of pixel values of the corrected image Under the condition that the sum of the squares of the differences of the average values is the smallest, the correction coefficient of the current background is calculated.

A further technical solution of the invention is: dividing the grouping of sensor units in the sensor array into at least two groups.

A further technical solution of the present invention is: grouping the sensor units in the sensor array into: according to the pixel value of the uniform radiation image output by the sensor unit in the sensor array, sequentially in the sensor array according to the pixel value size The sensor units are equally divided into groups.

A further technical solution of the present invention is to collect a background image of the sensor array under different temperature conditions, and different temperature conditions of the plurality of uniform radiation images cover an operating temperature range of the sensor array.

A further technical solution of the present invention is: in the grouping of the sensor units in the sensor array, the number of sensor units in the sensor array is q, the number of the packets is P, and the grouping satisfies: q/p 100.

A further technical solution of the present invention is: in the step of calculating the image correction coefficient, calculating an average value of the pixel values in the respective groups as an average value of calculating effective pixel values in the respective groups.

The technical solution of the present invention is: providing a non-uniform image correction method, the image is output by a sensor array, the sensor array includes a plurality of sensor units, the one sensor unit outputs a pixel value, and the sensor array is operated at different operating temperatures. a plurality of background images under conditions, wherein different temperature conditions of the plurality of background images cover an operating temperature range of the sensor array, and the background images are grouped according to a grouping manner of sensor units in the sensor array to obtain the a gain correction constant of the sensor array, the non-uniform image correction method comprising the following steps:

Obtain the current background image: Obtain the correction coefficient of the current background, and calculate the background image of the current working state of the sensor array according to the acquired background image and the correction coefficient of the current background. Obtain image correction result: Obtain image correction result according to non-uniformity two-point correction formula.

According to a further technical solution of the present invention, different temperature conditions of the plurality of background images uniformly cover an operating temperature range of the sensor array.

The technical solution of the present invention is: constructing a non-uniform image correction system, comprising a sensor array for outputting an image and an image correction unit, the sensor array comprising a plurality of sensor units, the one sensor unit outputting a pixel value, the image The correction unit includes an image acquisition module that acquires an image, a background calculation module that calculates a current background image, a correction coefficient calculation module that calculates a current background image correction coefficient, a gain correction constant calculation module that calculates a gain correction constant, and an image that acquires an image correction result. Obtaining a module, the image acquisition module collecting a plurality of background images under different working temperature conditions output by the sensor array, wherein different temperature conditions of the plurality of background images cover an operating temperature range of the sensor array, and the background image is The grouping manner of the sensor units in the sensor array is grouped; the correction coefficient calculation module calculates a correction coefficient of the current background image, and the background calculation module is based on the acquired background image and the correction system of the current background image. The background image is calculated in the current operating state of the sensor array; said gain correction module calculates the gain correction constant sensor array normal number; the correction image acquisition module acquires an image in accordance with a result of the two-point non-uniformity correction formula.

The technical effects of the present invention are: providing an image correction coefficient acquisition method, a non-uniform image correction method, and a system, by using at least two groups of sensor units in the sensor array, collecting a plurality of sensor arrays under different operating temperature conditions a background image, according to the grouping of the sensor units in the sensor array, the pixels of the pre-corrected image output by the sensor array are grouped correspondingly, and each pixel value of the pre-corrected image is acquired in groups, and the groups are calculated. The average value of the pixel values in the group of pre-corrected images is calculated under the condition that the sum of the squares of the differences between the average values of the two sets of pixel values of the corrected image is the smallest, and the correction coefficient of the current background is calculated. In the non-uniform image correction method, by acquiring the correction coefficient of the current background, calculating the background image of the current working state of the sensor array according to the collected background image and the correction coefficient of the current background, and acquiring the image according to the non-uniformity two-point correction formula Correct the result. The method for acquiring an image correction coefficient, the method for correcting the image of the non-uniform image, and the system of the present invention do not require a zero pad compared to the conventional prior art. At the same time, there is no need to emphasize the use of calculating the difference between adjacent pixels, the position requirements are not high, and the calculation method is simple. DRAWINGS

FIG. 1 is a flow chart of obtaining a correction coefficient according to the present invention.

2 is a flow chart of a corrected image of the present invention.

3 is a schematic structural view of a calibration system of the present invention. detailed description

The technical solutions of the present invention are further described below in conjunction with specific embodiments.

As shown in FIG. 1, a specific embodiment of the present invention is: Providing a method for acquiring an image correction coefficient, the image is output by a sensor array, the sensor array includes a plurality of sensor units, and the one sensor unit outputs one pixel. Values, the sensor units in the sensor array are at least two groups. Collecting a plurality of background images of the sensor array under different operating temperature conditions, wherein the background image refers to a uniform radiation image acquired under a certain working temperature condition, and the background image is grouped according to the sensor unit in the sensor array. Grouping. In a specific implementation process, different temperature conditions of the plurality of uniform radiation images cover an operating temperature range of the sensor array. The method for acquiring the image correction coefficient includes the following steps:

Step loo: group the pre-corrected images, gp: group the pixels of the pre-corrected image output by the sensor array according to the grouping of the sensor units in the sensor array.

Step 200: Calculate a correction coefficient of the current background, gP: acquire each pixel value of the pre-corrected image by group, calculate an average value of pixel values in each group, and satisfy the corrected image in the grouping of the pre-corrected image. Under the condition that the sum of the squares of the differences between the average values of the two sets of pixel values is the smallest, the correction coefficient of the current background is calculated.

The specific implementation process of the present invention is as follows: If the sensor array includes s sensor units, it is divided into g groups, where g takes an integer greater than 2. The pre-corrected images are grouped according to the grouping of the sensor units in the sensor array, gp, and the pre-corrected images are correspondingly divided into groups g, wherein g takes an integer greater than 2. The average value of the set of pixel values is calculated, and the image correction coefficient is calculated under the condition that the square of the difference between the average value of one set of pixel values and the average value of the other set of pixel values is the smallest.

The following specific examples are performed: if the pre-corrected image is divided into groups g, where g is an integer greater than 2, the average value of each group of pixel values is a _Vgi , where i is an integer from 1 to g.

Since: offset (x, y ) =k ₁ XF ₁ (x, y) +k ₂ XF ₂ (x, y) +--+k _n XF _n (x, y) +C

( 1 ) Where offset (x, y) represents the pixel value of the pixel whose current background image coordinate is (x, y), K ₂ , ... K _n , C are correction coefficients, F x, y) , F ₂ (x, y ), ···, F _n (x, y) are the pixel values of the pixels whose background image coordinates are (X, y) at different operating temperatures.

The output sensor array response value can be divided into two parts: O^offsetij+imgijXLij, where represents the output sensor array response value, offset represents the background of the sensor unit, im _gij represents the image signal output by the corrected sensor unit, representing the array elements Sensitivity.

Converted from O^offsetij+imgijXLij to: imgu =(0^ - offset^)/ , let Gain^l/ , get: imgij = (Oij - off setij) XGair j,

That is, IMG (x, y) = [0 (x, y) - offset (x, y) ] XGain (x, y) (2) The sum of all pixel values of the corrected image: s draw IMG

(3) where mIMG represents the sum of all pixel values of the Ζι group of the corrected image, _XZij represents the X coordinate of the jth pixel of the first group, y represents the y coordinate of the jth pixel of the first group, and Ci represents the ∑1 group The number of pixels.

The average pixel value of the corrected image: m^IMG _Z; =TMmIMG _Z; /d (4) where, ^1^10 _2; the first group of average pixels of the corrected image.

The sum of the squares of the differences between the average values of each set of pixel values of the corrected image:

Where, it represents the i-th group, which represents the j-th group, i≠j. Under the condition that s minimum is satisfied, Id, K ₂ , ... K _n , Co are calculated according to formulas (1), (2), (3), (4), (5). In the calculation process, the minimum two are used. The correction coefficients ^, K ₂ , ... K _n , C are obtained by any one of a multiplication method, a neural network method, and a simulated annealing method.

In the formula (5), let D _IMe =(m^IMG -m^IMG ) ² , and define D _IMe as follows: Find the corresponding group of each, F ₂ , ..., F _n « -avgF f , let f, t=l,

..., n, avg^. represents the mean of the pixel values in the Z" group of F _t , and _avg F represents the mean of the pixel values in the group of ^, where i ≠ j. Find the minimum value D _rain and the maximum value D _{raax of} D _t . If D _{IM (} ; > D _raax , let D _IMe =D _raax; if D _IMe <D _rain , then let D _IMe =D _rain . The small image information solves the interference of Id, K ₂ , ... K _n , C, resulting in better correction coefficients Id, K ₂ , ... K _n , Co The following is divided into two groups, one pixel per group as an example, and the least square method is used to obtain the correction coefficient.

The process of K ₂ , ... K _n , C:

Let the coordinates of one set of pixels be (xl, yl) and the coordinates of the other set of pixels be (x2, y2). According to formulas (1), (2), (3), (4), (5), then the formula The S in (5) is simplified into the following form:

S= [ (0 ( _Xl , _yi ) -K! XF! ( _Xl , _yi ) - K ₂ XF ₂ ( _Xl , ...... - K _n XF _n (x _Yl ) _C) X

Gain(x yj- (0 (x ₂ , y ₂ ) X Fi (x ₂ , y ₂ ) - K ₂ XF ₂ (x ₂ , y ₂ ) _ - K _n XF _n (x ₂ , y ₂ )_C)

XGain (x ₂ , y ₂ ) ] ²

Let: Δ0= 0(χι, yi) XGain(x yj- 0(x ₂ , y ₂ ) XGain(x ₂ , y ₂ ),

Fi ( i, yi) X Gain (xy - Fi (x ₂ , y ₂ ) X Gain (x ₂ , y ₂ ),

AF _n = F _n (x yj X Gain (xy - F _n (x ₂ , y ₂ ) X Gain (x ₂ , y ₂ ),

AC=CX (Gain (x yj - Gain (x ₂ , y ₂ ) )

贝ij: S= (AO-KiXAFi- K ₂ XAF ₂ -... - K _n XAF _n -AC) ² (6)

First, find the partial derivatives of Id, K ₂ , ... Κ _η , C in equation (6), and let the partial derivative be zero, and get the following system of equations:

△0XAF Factory Ki X AFi - K ₂ XAF ₂ XAF!- - K _n X AF _n X AFi-AC X AF^O

A0XAF ₂ - Ki X AFi X AF ₂ - K ₂ XAF ₂ ² - - K _n X AF _n X AF ₂ -AC X AF ₂ =0

A0XAF _n - KiXAFiXAFn - K ₂ XAF ₂ XAF _n - - K _n XAF _n ² -ACXAF _n =0

AO-KiXAFi- K ₂ XAF ₂ -... - K _n XAF _n -AC=0

Solve the above equations and get K ₂ , ... K _n , C.

By analogy, K ₂ , ... K _n , C are obtained in the case of a plurality of sets of multiple pixels.

In a specific embodiment, the grouping of the sensor units in the sensor array is equally divided into at least two groups, and the specific grouping manner of the sensor units in the sensor array is: according to the sensors in the sensor array The unit outputs the pixel value size of the uniform radiation image, and sequentially divides the sensor units in the sensor array into groups according to the pixel value size. Since the non-uniformity image is caused by the difference between the pixel value of a part of the pixels and the pixel value of the other part of the pixels, if the sorting is performed according to the pixel value size of the pixels, if there is non-uniformity, the mean between the groups There must be a difference, and the non-uniformity between the groups can be minimized under the condition that the sum of the squares of the differences between the average values of the two sets of pixel values of the corrected image is minimized, and the obtained correction coefficient is more good. Ben Ming In a specific embodiment, in the group of sensor units in the sensor array, the number of sensor units in the sensor array is q, the number of packets is P, and the grouping satisfies: q/p 100. In the process of grouping the sensor arrays, a better effect is that a certain number of packets must be reached, and the number of packets is too large, and the calculation amount is large. Therefore, in the case of balancing various aspects, the grouping is satisfied: q/p 100.

In a preferred embodiment of the invention, the average of the pixel values in the respective groups is calculated to calculate an average of the effective pixel values in the respective groups. The criterion for determining the effective pixel value is: first calculating the pixel value mean value avg of the group of pixels, and then calculating the pixel value mean square difference δ of the group of pixels, and setting the pixel value of the group of pixels to gray, if | gray-avg | < 2δ , then the pixel is a valid pixel.

As shown in FIG. 2, the present invention provides a non-uniform image correction method, the image is output by a sensor array, the sensor array includes a plurality of sensor units, and the one sensor unit outputs a pixel value, and the sensor array is differently operated. a plurality of background images under temperature conditions, different temperature conditions of the plurality of background images covering an operating temperature range of the sensor array, the background images being grouped according to a grouping manner of sensor units in the sensor array, acquiring The gain correction constant of the sensor array, the non-uniform image correction method includes the following steps:

Step 10: Obtain the current background image, gp: Obtain the correction coefficient of the current background, and calculate the background image of the current working state of the sensor array according to the acquired background image and the correction coefficient of the current background. The specific method of obtaining the image correction coefficient is calculated by the above image correction coefficient acquisition method, and will not be described in detail.

In a specific embodiment of the invention, the current background pixel value of coordinates (x, y):

Offset (x,y ) ^ XF! (x, y ) +K ₂ XF ₂ (x, y ) +K ₃ XF ₃ (x, y ) +... +K _n XF _n (x,y) +C, Since Id, K ₂ , ... K _n , C are obtained by the acquisition method of the non-uniform image correction coefficient, (x, y), F ₂ (x, y), F ₃ (x, y) ... F _n (x, y ) is obtained by acquiring the background image, thereby obtaining the current background image minus x, y), and by calculating the offset (x, y) of each pixel of the image, the offset of all the pixels of the image can be calculated.

Wherein, F ₂ , F ₃ ...... F _n are background images, by acquiring a background image, SP: collecting a plurality of uniform radiation images under different temperature conditions output by the sensor array, and covering different temperature conditions of the plurality of uniform radiation images The operating temperature range of the sensor array. In a specific embodiment of the present invention, if the plurality of uniform radiation images under different temperature conditions output by the sensor array are F ₂ , F _{3 ,} ... F _n , then the background image is F ₂ , F _{3 ,} ... F _n . In a specific embodiment of the invention, the temperature points at which the plurality of uniform radiation images are located are evenly distributed within the operating temperature range of the sensor array. Step 20: Acquire image correction result, gp: Obtain image correction result according to non-uniformity two-point correction formula.

The specific implementation process is as follows: According to the non-uniformity two-point correction formula: IMG (X, y) = [0 (x, y) - offset (x, y) ] XGain (x, y), where offset (x, y ) indicates the background pixel value of the current coordinate (x, y), Gain (x, y) indicates the gain correction constant of the sensor unit coordinate (x, y), and IMG (X, y) indicates the coordinate after correction (x , y) pixel value, 0 (x, y) represents the pre-corrected pixel value of coordinates (x, y). The correction value of all the pixels in the image is obtained by the formula, that is, the corrected image is obtained.

Among them, the acquisition of Gain (x, y) is based on the image acquisition gain correction constant of the uniform radiator under two different radiation intensities under the same ambient temperature condition. In a specific embodiment of the present invention, if the images of the uniform radiators BlackH and BlackL at two different radiation intensities under the same ambient temperature condition, the image gain correction constant Gain(i, j) is:

^ ^ BlackH (/, ;) ^ ^ BlackLii, j)

BlackH ( , j) BlackL(j, j) where: (i, j) represents the coordinates of the image pixel, w represents the number of lines of the image, and h represents the number of columns of the image.

Gain(i, j) is the gain correction constant of the (i, j) sensor unit in the sensor array. By calculating the gain correction constant of each sensor unit in the sensor array, the sensor array gain is normal. number.

The non-uniform image correction method of the invention obtains the correction coefficient of the current background, calculates the background image of the current working state of the sensor array according to the acquired background image and the correction coefficient of the current background, and acquires the image according to the non-uniformity two-point correction formula. Correct the result. The non-uniform image correction method of the present invention does not require a zero pad compared to the conventional prior art. At the same time, it is not necessary to emphasize the difference between the calculation of adjacent pixels, the position requirement is not high, and the calculation method is simple.

The technical solution of the present invention is: constructing a non-uniform image correction system, comprising a sensor array 2 for outputting an image and an image correction unit 1, the sensor array 2 comprising a plurality of sensor units, the one sensor unit outputting a pixel value, The image correction unit 1 includes an image acquisition module 11 that acquires an image, a background calculation module 13 that calculates a current background image, a correction coefficient calculation module 12 that calculates a current background image correction coefficient, and a gain correction constant calculation module that calculates a gain correction constant. 14 and an image acquisition module 15 that acquires an image correction result, and the image acquisition module 11 collects a sensor array a plurality of background images outputted under different operating temperature conditions of the column, different temperature conditions of the plurality of background images covering an operating temperature range of the sensor array, the background image being grouped by sensor units in the sensor array Performing grouping; the correction coefficient calculation module 12 calculates a correction coefficient of the current background image, and the background calculation module 13 calculates a background image in a current working state of the sensor array according to the acquired background image and the correction coefficient of the current background image; The gain correction constant module 14 calculates a gain correction constant of the sensor array; the image acquisition module 15 acquires an image correction result according to a non-uniformity two-point correction formula.

The specific working process of the present invention is as follows: the image acquisition module 11 collects a plurality of background images under different working temperature conditions of the sensor array, and different temperature conditions of the plurality of background images cover an operating temperature range of the sensor array. The correction coefficient calculation module 12 acquires the correction coefficient of the current background, and the specific acquisition method is calculated by the above image correction coefficient acquisition method, and will not be described in detail herein.

The background calculation module 13 calculates the background image of the current working state of the sensor array based on the acquired background image and the correction coefficient of the current background. The specific process is as follows: The current background of the coordinates (x, y) Pixel value:

Offset (x,y) = _l X¥ _l (x,y) +K ₂ XF ₂ (x, y) +K ₃ XF ₃ (x, y) + K _n X

F _n (x, y) + C, since Id, K ₂ , ... K _n , C are obtained by the acquisition method of the non-uniform image correction coefficient, (x, y), F ₂ (x, y), F ₃ (x, y) ...... F _n (x, y) is obtained by acquiring the background image, from which the current background image offset (x, y) can be obtained by calculating the offset (x, y) of each pixel of the image. , that is, the offset of all pixels of the image can be calculated.

Wherein, F ₂ , F _{3 ,} ... F _n are background images, the image acquisition module 11 collects a background image, gp: collects multiple uniform radiation images under different temperature conditions output by the sensor array, and the plurality of uniform radiations Different temperature conditions of the image cover the operating temperature range of the sensor array. In a specific embodiment of the present invention, if the plurality of uniform radiation images under different temperature conditions output by the sensor array are F ₂ , F _{3 ,} ... F _n , then the background image is F ₂ , F _{3 ,} ... F _n . In a specific embodiment of the invention, the temperature points at which the plurality of uniform radiation images are located are evenly distributed within the operating temperature range of the sensor array.

The image acquisition module 15 acquires an image correction result according to the non-uniformity two-point correction formula. The specific implementation process is as follows: According to the non-uniformity two-point correction formula: IMG (X, y) = [0 (x, y) - offset (x, y) ] XGain (x, y), where offset (x, y ) indicates the background pixel whose current coordinate is (x, y) The value, Gain ( x, y ), represents the gain correction constant of the sensor unit coordinate (x, y ), IMG ( x , y ) represents the pixel value of the (x, y) coordinate after correction, 0 ( X , y ) Represents a pre-corrected pixel value with coordinates (x, y). The correction value of all the pixels in the image is obtained by the formula, that is, the corrected image is obtained.

Among them, the acquisition of Gain (x, y) is based on the image acquisition gain correction constant of the uniform radiator under two different radiation intensities under the same ambient temperature condition. The gain correction constant calculation module 14 calculates the gain correction constant of the sensor array 2, the specific process is as follows: if the images of the uniform radiators BlackH and BlackL at two different radiation intensities under the same ambient temperature condition, the image gain is normal. Gain

( i, j ) is:

^ ^ BlackH (/, ;) ^ ^ BlackLii, j)

Gain (i, j) is the gain correction constant of the (i, j) sensor unit in the sensor array 2, and the sensor array 2 is obtained by calculating the gain correction constant of each sensor unit in the sensor array 2. Gain correction constant.

The technical effect of the present invention is: providing a non-uniform image correction system, by acquiring a correction coefficient of the current background, calculating a background image of the current working state of the sensor array according to the collected background image and the correction coefficient of the current background, and then according to the non- The uniformity two-point correction formula obtains the image correction result. The non-uniform image correction method of the present invention does not require a zero pad compared to the conventional prior art. At the same time, there is no need to emphasize the use of calculating the difference between adjacent pixels, the position requirements are not high, and the calculation method is simple.

The above is a further detailed description of the present invention in connection with the specific preferred embodiments. It is not intended that the specific embodiments of the invention are limited to the description. It will be apparent to those skilled in the art that the present invention may be practiced without departing from the spirit and scope of the invention.

Claims

Rights request

A method for acquiring an image correction coefficient, wherein the image is output by a sensor array, the sensor array includes a plurality of sensor units, the one sensor unit outputs a pixel value, and the sensor in the sensor array The unit has at least two groups, and collects a plurality of background images under different operating temperature conditions of the sensor array, wherein the background image is grouped according to a grouping manner of the sensor units in the sensor array, and the method for acquiring the image correction coefficient includes the following steps. :

The method of acquiring image correction coefficients according to claim 1, characterized in that the grouping of the sensor units in the sensor array is equally divided into at least two groups.

The method for acquiring an image correction coefficient according to claim 1 or 2, wherein the grouping of the sensor units in the sensor array is: outputting a pixel value of a uniform radiation image according to a sensor unit in the sensor array The size, in turn, divides the sensor units in the sensor array into groups according to the pixel value.

The method for acquiring an image correction coefficient according to claim 1, wherein a background image of the sensor array under different temperature conditions is acquired, and different temperature conditions of the plurality of uniform radiation images cover an operating temperature range of the sensor array .

The method for acquiring an image correction coefficient according to claim 3, wherein, in the grouping of the sensor units in the sensor array, the number of sensor units in the sensor array is q, and the number of the packets is p, The grouping satisfies: q/p 100.

The method for acquiring an image correction coefficient according to claim 1, wherein in the step of calculating an image correction coefficient, calculating an average value of pixel values in each group is calculating an effective pixel value in each group average value.

7. A non-uniform image correction method, wherein the image is output by a sensor array, the sensor array comprises a plurality of sensor units, and the one sensor unit outputs a pixel value, and the sensor array is collected under different operating temperature conditions. Multiple background images, the multiple background images are not The operating temperature range of the sensor array is covered by the same temperature condition, and the background image is grouped according to the grouping manner of the sensor units in the sensor array to obtain a gain correction constant of the sensor array, and the non-uniform image correction method Including the following steps:

Get the current background image: Obtain the correction coefficient of the current background, and calculate the background image of the current working state of the sensor array according to the acquired background image and the correction coefficient of the current background.

Obtain image correction result: Obtain image correction result according to non-uniformity two-point correction formula.

The non-uniform image correcting method according to claim 7, wherein different temperature conditions of the plurality of background images uniformly cover an operating temperature range of the sensor array.

A non-uniform image correction system, comprising: a sensor array for outputting an image and an image correction unit, the sensor array comprising a plurality of sensor units, the one sensor unit outputting a pixel value, the image correction unit The image acquisition module includes an image acquisition module, a background calculation module for calculating a current background image, a correction coefficient calculation module for calculating a current background image correction coefficient, a gain correction constant calculation module for calculating a gain correction constant, and an image acquisition module for acquiring an image correction result. The image acquisition module collects multiple background images under different operating temperature conditions output by the sensor array, and different temperature conditions of the plurality of background images cover an operating temperature range of the sensor array, and the background image is pressed by the sensor The grouping manner of the sensor units in the array is grouped; the correction coefficient calculation module calculates a correction coefficient of the current background image, and the background calculation module calculates the transmission according to the collected background image and the correction coefficient of the current background image. Background of the current operating state of the image array; module calculates the gain correction constant the gain correction constant sensor array; image acquisition module acquires the image correction results based on two-point non-uniformity correction formula.

10. The non-uniform image correction system of claim 9, wherein different temperature conditions of the plurality of background images uniformly cover an operating temperature range of the sensor array.