Disclosure of Invention
The invention provides a residual image testing method and a residual image testing device of an image sensor, which are used for solving the defect that some image sensors in the prior art do not have corresponding residual image testing methods or do not have corresponding testing environments to carry out residual image testing, and realizing the residual image testing of the image sensor which can be developed under the common environment.
The invention provides a residual image testing method of an image sensor, which comprises the following steps:
obtaining a first image and a second image by using an image sensor to be tested; wherein the second image is adjacent to and behind the first image;
determining a first pixel position of at least one cosmic ray instance point on the first image, and acquiring a first response value at the first pixel position on the second image; wherein the cosmic ray instance points are information of cosmic ray particles on the image;
and obtaining the residual image of the image sensor to be tested according to the first response value.
According to the method for testing the residual image of the image sensor, the first response value at the first pixel position on the second image is obtained, specifically, the second response value at the first pixel position on the second image is obtainedResponse value DN of1And compares the response value DN1Is determined as the first response value.
According to the afterimage testing method of the image sensor provided by the invention, the afterimage of the image sensor to be tested is obtained according to the first response value, and the method specifically comprises the following steps:
for all response values DN1Taking an average value to obtain a first average response value DN1ave;
According to the gain of the image sensor to be tested, the first average response value DN1aveAnd converting the residual image into a corresponding electronic number to obtain the residual image of the image sensor to be tested.
According to the afterimage testing method of the image sensor provided by the invention, after the afterimage of the image sensor to be tested is obtained according to the first response value, the method further comprises the following steps:
and acquiring the residual image percentage of the image sensor to be tested according to the residual image.
According to the afterimage testing method of the image sensor provided by the invention, the afterimage percentage of the image sensor to be tested is obtained according to the afterimage, and the method specifically comprises the following steps:
obtaining a response value DN of the first image at the first pixel position2The response value DN2As a second response value;
for all response values DN2Taking an average value to obtain a second average response value DN2ave;
According to the gain of the image sensor to be tested, the second average response value DN2aveConverting into corresponding electronic number, and averaging the first average response value DN1aveThe corresponding number of electrons divided by the second average response value DN2aveAnd obtaining the residual image percentage according to the corresponding number of electrons.
According to the afterimage testing method of the image sensor provided by the invention, a first image and a second image are obtained by using the image sensor to be tested, and the method specifically comprises the following steps:
placing the image sensor to be tested in a common experimental environment, wherein the surface of the image sensor needs to be shielded, or placing the image sensor in a completely black environment;
and continuously exposing the image sensor to be tested within preset time to obtain a first image and a second image of the image sensor to be tested.
According to the afterimage testing method of the image sensor provided by the invention, the afterimage testing method of the image sensor comprises the following steps:
obtaining a first image and an nth image by using an image sensor to be tested; wherein the nth image is the (n-1) th image after the first image, and n-2 images are sequentially arranged between the nth image and the first image;
determining a first pixel position of at least one cosmic ray case point on the first image, and acquiring response values at the first pixel position on all images from the nth image to the (n-1) th image; wherein the cosmic ray instance points are information of cosmic ray particles on the image;
and obtaining the residual image of the image sensor to be tested according to the response value.
The present invention also provides an afterimage testing apparatus of an image sensor, including:
the first acquisition module is used for acquiring a first image and a second image by using an image sensor to be tested; wherein the second image is adjacent to and behind the first image;
a second obtaining module, configured to determine a first pixel position of at least one cosmic ray instance point on the first image, and obtain a first response value at the first pixel position on the second image; wherein the cosmic ray instance points are information of cosmic ray particles on the image;
and the third acquisition module is used for acquiring the residual image of the image sensor to be tested according to the first response value.
The invention also provides an electronic device, which comprises a memory, a processor and a computer program stored on the memory and capable of running on the processor, wherein the processor executes the program to realize the steps of the afterimage testing method of the image sensor.
The present invention also provides a non-transitory computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the steps of the method for image retention testing of an image sensor as described in any one of the above.
The invention provides a residual image testing method and a device of an image sensor, which can effectively test the residual image performance of various image sensors by continuously acquiring images of the image sensor to be tested in a common environment (even in a space orbit environment), analyzing the pixel position (position information) of a cosmic ray case point in one image of the image sensor to be tested and the DN (image information) value of the same pixel position on the next image of the image to obtain the residual image of the image sensor to be tested, and obtaining the final residual image of the image sensor to be tested by statistical analysis of a large number of cases. The residual image testing method and the residual image testing device of the image sensor are simple and easy to operate, have strong environmental adaptability, can accurately obtain the residual image of the image sensor, are suitable for development units and testing users of the image sensor, and can be applied to the residual image testing method and the residual image testing device of the image sensor for residual image measurement of industrial products and scientific research products.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the prior art, some image sensors do not have corresponding afterimage testing methods or do not have corresponding testing environments to perform afterimage testing, for example, the surfaces of some image sensors need to be coated with films and shielded from light to prevent pollution, and the afterimage testing cannot be performed by using a method of strong visible light irradiation.
The invention aims to provide a residual image testing method and a residual image testing device of an image sensor, which can be applied to various types of image sensors in a common environment, even a space orbit environment.
The afterimage testing method of the image sensor of the present invention is described below with reference to fig. 1, 14 and 15, and includes the steps of:
s100, obtaining a first image in an exposure state and a second image in the exposure state by using an image sensor to be tested, wherein the first image and the second image are obtained after the image sensor is subjected to dark exposure, and the second image is adjacent to the first image and behind the first image. In step S100, the images of the image sensor after continuous exposure are acquired under a normal environment, such as a normal experimental environment, which refers to a normal laboratory environment, in which the image sensor needs to be shielded from light or placed in a black box or the like under a full black condition.
S200, determining a first pixel position of at least one cosmic ray case point on the first image, and acquiring a first response value at the first pixel position on the second image. The cosmic ray instance point is information of a cosmic ray particle on an image, and the information comprises a track, energy and the like. In particular, the second image may be acquired at the first pixel positionIn response to the value DN1And sends the response value DN1Is determined as the first response value.
In this embodiment, the first response value and the subsequent response value refer to a DN value, where the DN value (Digital Number) is a remote sensing image pixel brightness value used for recording a gray level value of a ground feature, and the DN value is a unitless integer value, and the size of the DN value is related to the Number of photons or electrons recorded by the image sensor. The first pixel position is coordinate information of the cosmic ray case point in the first image, and the coordinate information comprises row coordinate information and column coordinate information, namely, horizontal and vertical coordinate information under a rectangular plane coordinate system.
For example, if a cosmic ray case point responds to the original image with coordinates (X, Y), the DN value of the response of the point with coordinates (X, Y) in the image to be tested is obtained, and this DN value is then used as the first response value.
Cosmic ray particles are high-energy particles that travel near the speed of light in the universe and include particles such as protons, helium nuclei, electrons, neutrons, and the like. The vast majority of which are protons. Cosmic ray particles are ubiquitous in the earth environment, and can exist stably in a laboratory environment due to high energy and strong penetrating power. The count rate of cosmic ray particles at low altitude is about 1/cm/min. The image sensor is sensitive to visible light photons, and can effectively record information such as tracks and energy of charged particles such as electrons and protons. When the charged particles pass through a medium of the image sensor, energy deposition signals are generated through ionization, so that structures such as bright spots and bright lines are finally presented on the image sensor, the imaging effect is similar to that of visible light photons, and the charged particles are difficult to distinguish.
The first image is an exposed image or a plurality of consecutive images, and the second image is an unexposed image or a plurality of consecutive images.
In step S200, the method for testing residual images of an image sensor according to the present invention uses cosmic ray particles for testing, that is, the method can use cosmic ray particles for testing in an uncharged particle testing environment, so that the overall testing method is simple and easy to operate.
In this embodiment, in order to avoid the influence of the statistical error, the larger the data size is, the better the data size is, for example, more than 10000 cosmic ray case points are selected for statistical analysis, so that the average value and the number of electrons obtained in the subsequent step S300 are more accurate, and the number of the adopted cosmic ray case points can be adjusted correspondingly according to the experiment and the test requirements.
S300, obtaining the residual image of the image sensor to be tested according to the first response value.
In summary, the method for testing the afterimage of the image sensor of the present invention continuously obtains the image of the image sensor to be tested in a common environment, even in a space orbit environment, obtains the afterimage of the image sensor to be tested by analyzing the pixel position of the cosmic ray case point in one image of the image sensor to be tested and the DN value at the same pixel position on the next image of the image, and obtains the final afterimage of the image sensor to be tested by statistical analysis of a large number of cases. The residual image testing method of the image sensor is simple and easy to operate, has strong environmental adaptability, can accurately obtain the residual image of the image sensor, is suitable for development units and testing users of the image sensor, and can be applied to the residual image testing method of the image sensor to carry out residual image measurement on industrial products and scientific research products.
In this embodiment, in order to avoid the influence of the statistical error in step S220, it is better that the data amount is larger, for example, 10000 or more cosmic ray case points are selected for statistical analysis, so that the average value and the number of electrons obtained in the subsequent step S300 are more accurate.
The method for testing the residual image of the image sensor according to the present invention is described below with reference to fig. 2, where step S300 specifically includes the following steps:
s310, DN to all response values1Taking an average value to obtain a first average response value DN1ave;
S320, according to the gain of the image sensor to be tested, dividing the first average response value DN1aveConversion into a corresponding number of electrons, in particular a first average response value DN1aveAnd multiplying the gain to obtain a corresponding electronic number to obtain the residual image of the image sensor to be tested.
The method for testing the afterimage of the image sensor according to the present invention is described below with reference to fig. 3, and the following steps are included after step S300:
s400, according to the afterimage, acquiring the afterimage percentage of the image sensor to be tested, wherein the afterimage percentage refers to the afterimage percentage of the second image relative to the first image, and the performance of the image sensor can be visually displayed through the numerical value of the afterimage percentage.
The method for testing the residual image of the image sensor according to the present invention is described below with reference to fig. 4, where step S400 specifically includes the following steps:
s410, acquiring a response value DN of a first pixel position on the first image2Will respond to the value DN2As a second response value.
S420, DN to all response values2Taking an average value to obtain a second average response value DN2ave;
S430, according to the gain of the image sensor to be tested, calculating a second average response value DN2aveConversion into a corresponding number of electrons, in particular a second average response value DN2aveMultiplying the gain by the gain to obtain a corresponding number of electrons, and averaging the first average response value DN1aveThe corresponding number of electrons divided by the second average response value DN2aveAnd obtaining the residual image percentage according to the corresponding number of electrons.
Referring to table 1, 23733 cosmic ray case points are selected from table 1 for statistical analysis, and information of the first 7 cosmic ray case points is displayed.
Table 1 first pixel positions of partial cosmic ray instance points in fig. 14, second response values, and first pixel positions of these cosmic ray instance points are the first response values in fig. 15
| Serial number | Column coordinate | Line coordinate | Second response value | First response value |
| 1 | 2470 | 2400 | 420.8 | 5.4 |
| 2 | 2436 | 2089 | 546.7 | -2.7 |
| 3 | 2436 | 2090 | 557.4 | -5.4 |
| 4 | 2286 | 2193 | 289.4 | -2.7 |
| 5 | 2285 | 2194 | 519.9 | 0 |
| 6 | 2286 | 2194 | 184.9 | -2.7 |
| 7 | 1245 | 767 | 833.5 | 0 |
The method for testing the residual image of the image sensor according to the present invention is described below with reference to fig. 5, where step S100 specifically includes the following steps:
s110, placing the image sensor to be tested in a common experimental environment, wherein it can be understood that the reading circuit of the image sensor to be tested can also be placed in the common experimental environment, the surface of the image sensor needs to be shielded in the common experimental environment, or the image sensor is placed in a black box or other completely black environments, and the reading circuit does not need to be used.
S120, continuously exposing the image sensor to be tested within a preset time, turning off an exposure power supply after the preset time is reached, ending exposure of the image sensor to be tested, and obtaining and storing a first image and a second image of the image sensor to be tested, wherein the first image and the second image are both in an exposure state.
The afterimage testing apparatus of the image sensor of the present invention is described below with reference to fig. 6, which is different from the method of the above embodiment, and the afterimage testing method includes the following steps:
s101, obtaining a first image and an nth image by using an image sensor to be tested, wherein the nth image is an n-1 th image behind the first image, and n-2 images are sequentially arranged between the nth image and the first image.
S201, determining a first pixel position of at least one cosmic ray case point on the first image, and acquiring response values at the first pixel position on all images from the nth image to the (n-1) th image, wherein the cosmic ray case point is information of cosmic ray particles on the images.
S301, obtaining the residual image of the image sensor to be tested according to the response value.
In this embodiment, the second image may be one or more images, and if the second image is a plurality of images, the images in the exposure state are sequentially acquired. In the conventional afterimage test, only afterimages of the first image relative to the first image, which are arranged in sequence in the second image after the test, are required, but it is understood that, in the afterimage test method of the image sensor of the present invention, afterimages of other images in the second image relative to the first image may also be acquired.
The following describes the afterimage testing device of the image sensor provided by the present invention, and the afterimage testing device of the image sensor described below and the afterimage testing method of the image sensor described above can be referred to in correspondence with each other.
The afterimage test apparatus of the image sensor of the present invention is described below with reference to fig. 7, 14 and 15, and includes:
the first obtainingmodule 100 is configured to obtain, by using an image sensor to be tested, a first image in an exposure state and a second image in the exposure state, where the first image and the second image are both obtained by performing dark exposure post-processing on the image sensor, and the second image is adjacent to and behind the first image. It should be noted that, the first acquiringmodule 100 acquires images after continuous exposure of the image sensor in a common environment, for example, a common experimental environment, where the image sensor needs to be shielded from light or placed in a black box under a completely black condition.
Second acquisitionA module 200 is configured to determine a first pixel position of at least one cosmic ray instance point on a first image, and obtain a first response value at the first pixel position on a second image. The cosmic ray instance point is information of a cosmic ray particle on an image, and the information comprises a track, energy and the like. In particular, it may be that a response value DN of the second image at the first pixel position is obtained1And sends the response value DN1Is determined as the first response value.
In this embodiment, the first response value and the subsequent response value refer to a DN value (Digital Number), where the DN value is a remote sensing image pixel brightness value used for recording a gray level value of a ground feature, and the DN value is a unitless integer value, and the size of the DN value is equal to the photon Number or the electron Number recorded by the image sensor. The first pixel position is coordinate information of the cosmic ray case point in the first image, and the coordinate information comprises row coordinate information and column coordinate information, namely, horizontal and vertical coordinate information under a rectangular plane coordinate system.
For example, if a cosmic ray case point responds to the original image with coordinates (X, Y), the DN value of the response of the point with coordinates (X, Y) in the image to be tested is obtained, and this DN value is then used as the first response value.
Cosmic ray particles are high-energy particles that travel near the speed of light in the universe and include particles such as protons, helium nuclei, electrons, neutrons, and the like. The vast majority of which are protons. Cosmic ray particles are ubiquitous in the earth environment, and can exist stably in a laboratory environment due to high energy and strong penetrating power. The count rate of cosmic ray particles at low altitude is about 1/cm/min. The image sensor is sensitive to visible light photons, and can effectively record information such as tracks and energy of charged particles such as electrons and protons. When the charged particles pass through a medium of the image sensor, energy deposition signals are generated through ionization, so that structures such as bright spots and bright lines are finally presented on the image sensor, the imaging effect is similar to that of visible light photons, and the charged particles are difficult to distinguish.
The first image is an image or a plurality of continuous images, and the second image is an image or a plurality of continuous images.
In the second obtainingmodule 200, the afterimage testing method of the image sensor of the present invention uses cosmic ray particles for testing, that is, the testing method can use cosmic ray particles for testing in an uncharged particle testing environment, so that the overall testing method is simple and easy to operate.
In this embodiment, in order to avoid the influence of the statistical error, the larger the data size is, the better the data size is, for example, more than 10000 cosmic ray case points are selected for statistical analysis, so that the average value and the number of electrons obtained by the subsequent third obtainingmodule 300 are more accurate, and the number of the adopted cosmic ray case points can be correspondingly adjusted according to the experiment and the test requirements.
And a third obtainingmodule 300, configured to obtain an afterimage of the image sensor to be tested according to the first response value.
In summary, the method for testing the afterimage of the image sensor of the present invention continuously obtains the image of the image sensor to be tested in a common environment, even in a space orbit environment, obtains the afterimage of the image sensor to be tested by analyzing the pixel position of the cosmic ray case point in one image of the image sensor to be tested and the DN value at the same pixel position on the next image of the image, and obtains the final afterimage of the image sensor to be tested by statistical analysis of a large number of cases. The residual image testing method of the image sensor is simple and easy to operate, has strong environmental adaptability, can accurately obtain the residual image of the image sensor, is suitable for development units and testing users of the image sensor, and can be applied to the residual image testing method of the image sensor to carry out residual image measurement on industrial products and scientific research products.
The following describes the afterimage testing method of the image sensor according to the present invention with reference to fig. 8, where the third obtainingmodule 300 specifically includes:
a second obtainingunit 310 forFor all response values DN1Taking an average value to obtain a first average response value DN1ave;
Aconversion unit 320 for converting the first average response value DN according to the gain of the image sensor to be tested1aveConversion into a corresponding number of electrons, in particular a first average response value DN1aveAnd multiplying the gain to obtain corresponding electrons to obtain the residual image of the image sensor to be tested.
The afterimage test apparatus of the image sensor of the present invention is described below with reference to fig. 9, and the test apparatus further includes:
theperformance determining module 400 is configured to obtain an afterimage percentage of the image sensor to be tested according to the afterimage, where the afterimage percentage refers to an afterimage percentage of the second image relative to the first image, and the performance of the image sensor can be visually displayed through a value of the afterimage percentage.
In the following, the image sticking test apparatus of the image sensor according to the present invention is described with reference to fig. 10, and theperformance determining module 400 specifically includes:
a third obtainingunit 410 for obtaining a response value DN of the first pixel position1Will respond to the value DN1As a second response value.
A fourth obtainingunit 420 for obtaining DN for all response values2Taking an average value to obtain a second average response value DN2ave;
Aperformance determining unit 430 for determining the second average response value DN according to the gain of the image sensor to be tested2aveConversion into a corresponding number of electrons, in particular a second average response value DN2aveMultiplying the gain by the first average response value DN to obtain the corresponding electronic number2aveThe corresponding number of electrons divided by the second average response value DN2aveAnd obtaining the residual image percentage according to the corresponding number of electrons.
In the following, referring to fig. 11, the residual image testing apparatus of the image sensor of the present invention is described, wherein the first obtainingmodule 100 specifically includes:
theenvironment simulation unit 110 is configured to place the image sensor to be tested in a common experiment environment in which the surface of the image sensor needs to be shielded from light, or place the image sensor in a black box or other completely black environments.
Thecontinuous exposure unit 120 is configured to perform continuous exposure on the image sensor to be tested within a preset time, turn off an exposure power supply after a preset time is reached, end exposure on the image sensor to be tested, obtain and store a first image and a second image of the image sensor to be tested, where the first image and the second image are both in an exposure state.
An afterimage testing apparatus of an image sensor of the present invention, which is different from the method of the above embodiment, is described below with reference to fig. 12, and includes:
the fourth obtainingmodule 101 is configured to obtain an image and an nth image by using the image sensor to be tested, where the nth image is an n-1 th image after the first image, and n-2 images sequentially arranged between the nth image and the first image.
A fifth obtainingmodule 201, configured to determine a first pixel position of at least one cosmic ray instance point on the first image, and obtain response values at the first pixel position on all images from the nth image to the n-1 st image, where the cosmic ray instance point is information of cosmic ray particles on the images.
A sixth obtainingmodule 301, configured to obtain an afterimage of the image sensor to be tested according to the response value.
In this embodiment, the second image may be one or more images, and if the second image is more than one image, the unexposed images are acquired in sequence. In the conventional afterimage test, only afterimages of the first image relative to the first image, which are arranged in sequence in the second image after the test, are required, but it is understood that, in the afterimage test method of the image sensor of the present invention, afterimages of other images in the second image relative to the first image may also be acquired.
Fig. 13 illustrates a physical structure diagram of an electronic device, and as shown in fig. 13, the electronic device may include: a processor (processor)810, acommunication Interface 820, amemory 830 and acommunication bus 840, wherein theprocessor 810, thecommunication Interface 820 and thememory 830 communicate with each other via thecommunication bus 840. Theprocessor 810 may invoke logic instructions in thememory 830 to perform an afterimage testing method of an image sensor, the afterimage testing method comprising the steps of:
s100, obtaining a first image and a second image by using an image sensor to be tested, wherein the second image is adjacent to and behind the first image.
S200, determining a first pixel position of at least one cosmic ray case point on the first image, and acquiring a first response value at the first pixel position on the second image. The cosmic ray case points are information of cosmic ray particles on the image.
S300, obtaining the residual image of the image sensor to be tested according to the first response value.
In addition, the logic instructions in thememory 830 may be implemented in software functional units and stored in a computer readable storage medium when the logic instructions are sold or used as independent products. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
In another aspect, the present invention also provides a computer program product comprising a computer program stored on a non-transitory computer readable storage medium, the computer program comprising program instructions which, when executed by a computer, enable the computer to perform the image retention test method of an image sensor provided by the above methods, the image retention test method comprising the steps of:
s100, obtaining a first image and a second image by using an image sensor to be tested, wherein the second image is adjacent to and behind the first image.
S200, determining a first pixel position of at least one cosmic ray case point on the first image, and acquiring a first response value at the first pixel position on the second image. The cosmic ray case points are information of cosmic ray particles on the image.
S300, obtaining the residual image of the image sensor to be tested according to the first response value.
In yet another aspect, the present invention also provides a non-transitory computer readable storage medium having stored thereon a computer program, which when executed by a processor is implemented to execute the image retention test method of the image sensor provided in each of the above, the image retention test method comprising the steps of:
s100, obtaining a first image and a second image by using an image sensor to be tested, wherein the second image is adjacent to and behind the first image.
S200, determining a first pixel position of at least one cosmic ray case point on the first image, and acquiring a first response value at the first pixel position on the second image. The cosmic ray case points are information of cosmic ray particles on the image.
S300, obtaining the residual image of the image sensor to be tested according to the first response value.
The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.