KR-20260065476-A - Method, and System for Evaluating Pixel Defects by Compensating for Luminance Variations

KR20260065476AKR 20260065476 AKR20260065476 AKR 20260065476AKR-20260065476-A

Abstract

The present invention relates to an apparatus for determining pixel defects in a camera that includes an image sensor and outputs image data based on a signal output from the image sensor, the apparatus comprising: a receiver for receiving image data output from the camera; and a processor for processing image data applied to the receiver; wherein the processor is configured to divide the image data into at least one region based on the brightness distribution of the image data, and is configured to extract defective pixels based on a criterion for each divided region.

Inventors

박진영
우정우
이정훈

Assignees

엘지이노텍 주식회사

Dates

Publication Date: 20260508
Application Date: 20250429
Priority Date: 20241101

Claims (10)

A device for determining pixel defects of an image sensor for a camera that includes an image sensor and outputs image data based on a signal output from the image sensor, A receiver for receiving image data output from the above camera; and A processor for processing image data applied to the receiver; comprising The above processor is: The image data is configured to be divided into at least one region based on the brightness distribution of the image data, and Configured to extract defective pixels based on the criteria for each of the aforementioned separated regions, A device for determining pixel defects.
In Article 1, The above processor is, Each of the above at least one region is configured to distinguish regions such that the brightness difference between pixels included within the region is similar, and Among the pixels included within the above-described regions, configured to extract pixels presumed to be defective based on the brightness deviation of the pixels relative to the criteria for each of the above-described regions. A device for determining pixel defects.
In Article 1, The above processor is, It is configured to classify types of pixel defects from the extracted defect pixels, and The types of pixel defects mentioned above are, At least one of a cold pixel, a hot pixel, a dead pixel, or a noise pixel, A device for determining pixel defects.
In Article 1, The above processor is, Configured to generate a report containing information about the aforementioned extracted defect pixels, A device for determining pixel defects.
In Article 1, The above processor is, Configured to set the operating conditions of the above image sensor as default conditions, A device for determining pixel defects.
In Article 1, The above processor is, A method configured to extract defective pixels based on criteria for each of the aforementioned separated regions by utilizing at least one algorithm among K-Means Clustering, Adaptive Thresholding, Region Growing, Gaussian Mixture Models (GMM), Edge Detection, and Histogram-Based Segmentation algorithms, A device for determining pixel defects.
In Article 4, The above processor is, Configured to generate a report in at least one of table format, map image format, and CSV format, A device for determining pixel defects.
A method in which a pixel defect determination device determines a pixel defect of an image sensor in a camera that includes an image sensor and outputs image data based on a signal output from the image sensor, A receiving step in which the receiving unit of the pixel defect determination device receives image data output from the camera; and A processing step in which the processor of the pixel defect determination device processes image data authorized to the receiver; is included, The above processing steps are: A division step in which the processor divides the image data into at least one region based on the brightness distribution of the image data; and An extraction step in which the processor extracts defective pixels based on criteria for each of the aforementioned separated regions; comprising Method for determining pixel defects.
In Article 8, The above classification step is, The method further includes the step of the processor dividing regions such that each of the at least one region has a similar brightness deviation between pixels included within the region. The above extraction step is, The method further comprises the step of configuring the processor to extract pixels presumed to be defective among the pixels included within the aforementioned separated regions, based on the brightness deviation of the pixels relative to the criteria for each of the aforementioned separated regions. Method for determining pixel defects.
In Article 9, It further includes a classification step in which the processor classifies the type of pixel defect from the extracted defect pixels; and The above classification step is, The method further comprises the step of classifying the pixel defect into at least one of a cold pixel, a hot pixel, a dead pixel, and a noise pixel by the processor. Method for determining pixel defects.

Description

Method, and System for Evaluating Pixel Defects by Compensating for Luminance Variations The present invention relates to a quality evaluation technology for an image sensor. Specifically, it relates to a technology for detecting pixel defects in an image sensor. When conventional image sensors are placed under a uniform light source, the difference in light intensity between the center and periphery of the image results in an uneven brightness distribution, which distorts defect detection criteria. Furthermore, static criteria, such as the overall brightness average or a predetermined threshold, do not account for light intensity deviations; consequently, errors occur where normal pixels are misidentified or defects are missed. Additionally, static criteria lack adaptability to changes in the image sensor's test environment. Moreover, for image sensors with a wide field of view, it is difficult to provide uniform illumination across the entire angle of view. Finally, it is difficult to distinguish whether pixels detected as defective are due to image brightness deviations or actual pixel defects. FIG. 1a is a diagram illustrating the configuration of a system for inspecting pixel defects of an image sensor according to one embodiment of the present invention. FIG. 1b is a diagram illustrating image data output from a pixel defect inspection target device according to one embodiment of the present invention. FIG. 2a is a drawing for explaining pixel defects according to an embodiment of the present invention. FIG. 2b is a conceptual diagram for explaining the shadow phenomenon of image data according to one embodiment of the present invention. FIG. 3 is a drawing for explaining a lighting device according to an embodiment of the present invention. FIG. 4 is a diagram illustrating the step of inspecting pixel defects of an image sensor according to one embodiment of the present invention. FIG. 5 is a diagram illustrating a pixel defect evaluation area separated from image data having a shading phenomenon according to an embodiment of the present invention. FIG. 6 is a diagram illustrating a defective pixel information report, which is the result of a pixel defect inspection device according to one embodiment of the present invention. Specific details of the embodiments are included in the detailed description and drawings. The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components. FIG. 1a is a diagram illustrating the configuration of a system for inspecting pixel defects of an image sensor according to an embodiment of the present invention. FIG. 1b is a diagram illustrating image data output from a pixel defect inspection target device according to an embodiment of the present invention. Referring to FIG. 1a, a system (10) for inspecting pixel defects of an image sensor may include a pixel defect inspection target device (100), a lighting device (200), and a pixel defect inspection device (300). Additionally, the pixel defect inspection target device (100) may include an image sensor (110) and an optical system (120). According to one embodiment of the present invention, a pixel defect inspection device (300) may include a receiving unit (310), a processor (320), and a storage unit (330). Specifically, the receiving unit (310) may receive data output from a pixel defect inspection target device (100). Specifically, the data output from the pixel defect inspection target device (100) may include image data or brightness code data of the image data. According to one embodiment of the present invention, the processor (320) can determine whether there is a defect in at least one pixel included in the image sensor (110) based on data output from the pixel defect inspection target device (100). A specific method for determining whether there is a pixel defect is described in detail below in the description of the step (S10) of inspecting pixel defects in the image sensor. According to one embodiment of the present invention, the storage unit (330) may store data authorized by the receiving unit (310) or result data regarding whether there is a pixel defect determined by the processor (320). According to one embodiment of the present invention, the pixel defect inspection target device (100) may be a device that is inspected in a system (10) for inspecting pixel defects. In this case, the pixel defect inspec