Image sensor operation method and image sensor

Abstract

A method for operating an image sensor, the image sensor being provided with a 4-row x 4-column pixel group including 4 sub-pixel groups, each sub-pixel group including 4 pixels of 2 rows x 2 columns, the method comprising: selecting and reading out a first pixel from among the 4 pixels in a first row of the pixel group; in a second row of the pixel group, selecting and reading out a second pixel from a sub-pixel group other than the sub-pixel group including the first pixel; in a third row of the pixel group, selecting and reading out a third pixel from a column other than a column including the first pixel and a column including the second pixel; and in a fourth row of the pixel group, selecting and reading out a fourth pixel from a column other than a column including the first pixel, a column including the second pixel, and a column including the third pixel.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Korean Patent Application No. 10-2021-0121577, filed on September 13, 2021, which is hereby incorporated by reference in its entirety. Technical Field

[0003] Various embodiments of the present invention relate to image sensors. Background Art

[0004] In a complementary metal oxide semiconductor (CMOS) image sensor (CIS), speed and power are in a trade-off relationship. Therefore, current CMOS image sensors mainly adopt a column parallel structure, which has an optimal trade-off relationship between speed and power. Because the column parallel structure makes it difficult to integrate an analog-to-digital converter (ADC) in a narrow pixel width, a simple single-slope analog-to-digital converter (ADC) is mainly used. Summary of the invention

[0005] Embodiments of the present invention are directed to an image sensor that randomly selects and senses a portion of pixels.

[0006] According to an embodiment of the present invention, a method for operating an image sensor is provided, wherein the image sensor is provided with a 4-row x 4-column pixel group, the 4-row x 4-column pixel group includes 4 sub-pixel groups, each sub-pixel group includes 4 pixels of 2 rows x 2 columns, the method including: selecting and reading out a first pixel from the 4 pixels in the first row of the pixel group; in the second row of the pixel group, selecting and reading out a second pixel from the sub-pixel group other than the sub-pixel group including the first pixel; in the third row of the pixel group, selecting and reading out a third pixel from the column other than the column including the first pixel and the column including the second pixel; and in the fourth row of the pixel group, selecting and reading out a fourth pixel from the column other than the column including the first pixel, the column including the second pixel, and the column including the third pixel.

[0007] According to another embodiment of the present invention, a method for operating an image sensor is provided, the image sensor being provided with an 8-row x 8-column pixel group, the 8-row x 8-column pixel group including 8 sub-pixel groups, each sub-pixel group including 8 pixels of 4 rows x 2 columns, the method comprising: selecting and reading out a first pixel from among the 8 pixels in a first row of the pixel group; in a second row of the pixel group, selecting and reading out a second pixel from a sub-pixel group other than the sub-pixel group including the first pixel; in a third row of the pixel group, selecting and reading out a third pixel from a sub-pixel group other than the sub-pixel group including the first pixel and the sub-pixel group including the second pixel; and in a fourth row of the pixel group, selecting and reading out a fourth pixel from a sub-pixel group other than the sub-pixel group including the first pixel, the sub-pixel group including the second pixel, and the sub-pixel group including the third pixel.

[0008] According to another embodiment of the present invention, a method for operating an image sensor is provided with an 8-row x 8-column pixel group, the 8-row x 8-column pixel group includes 8 sub-pixel groups, each sub-pixel group includes 8 pixels of 2 rows x 4 columns, the method includes: selecting and reading out a first pixel from the 8 pixels in a first row of the pixel group; in a second row of the pixel group, selecting and reading out a second pixel from a sub-pixel group other than the sub-pixel group including the first pixel; in a third row of the pixel group, selecting and reading out a third pixel from a column other than a column including the first pixel and a column including the second pixel; and in a fourth row of the pixel group, selecting and reading out a fourth pixel from a column other than a column including the sub-pixel group including the third pixel, a column including the first pixel, and a column including the second pixel.

[0009] According to another embodiment of the present invention, a method for operating an image sensor, the image sensor is provided with an N-row×N-column pixel group, the N-row×N-column pixel group includes N sub-pixel groups, each sub-pixel group includes N adjacent pixels, wherein N is an integer equal to or greater than 4, the method comprising: selecting and reading out a first pixel from among the N pixels in a first row of the pixel group; in a second row of the pixel group, selecting and reading out a second pixel from a sub-pixel group other than the sub-pixel group including the first pixel; selecting and reading out a third pixel from among the N pixels in a third row of the pixel group; , the third pixel is not a pixel included in the sub-pixel group including the first pixel, a pixel included in the sub-pixel group including the second pixel, a pixel in the column including the first pixel, and a pixel in the column including the second pixel; and in the fourth row of the pixel group, a fourth pixel is selected and read out, and the fourth pixel is not a pixel included in the sub-pixel group including the first pixel, a pixel included in the sub-pixel group including the second pixel, a pixel included in the sub-pixel group including the third pixel, a pixel in the column including the first pixel, a pixel in the column including the second pixel, and a pixel in the column including the third pixel.

[0010] According to yet another embodiment of the present invention, an image sensor includes: a pixel array including N rows x N columns of pixel groups, each pixel group including N sub-pixel groups, each sub-pixel group including N adjacent pixels, where N is an integer equal to or greater than 4; a row decoder suitable for selecting pixels of the pixel array for each row and suitable for controlling operations; a readout circuit suitable for performing analog-to-digital conversion on pixel signals output by pixels in the row selected by the row decoder in the pixel array; and a compression controller suitable for controlling the readout circuit to read out a portion of the columns of the pixel array rather than all of the columns during a compression sensing operation.

[0011] According to another embodiment of the present invention, a method for operating an image sensor includes: dividing a pixel array into groups each having NxN pixels, each group being divided into N subgroups, each subgroup having N pixels, where N is 4 or greater; and performing a compressed sensing operation on the pixel array row by row by reading out a maximum of a single pixel from each row in each group and a maximum of a single pixel from each column and a maximum of a single pixel in each subgroup. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a block diagram illustrating an image sensor according to an embodiment of the present invention.

[0013] Figure 2 and Figure 3 A rule for selecting pixels to be read out from among pixels of a pixel array when an image sensor performs a compressive sensing operation according to an embodiment of the present invention is shown.

[0014] Figure 4 An operation of selecting pixels during a compressive sensing operation of an image sensor according to a first embodiment of the present invention is shown.

[0015] Figure 5 and Figure 6 An operation of selecting pixels during a compressive sensing operation of an image sensor according to a second embodiment of the present invention is shown.

[0016] Figure 7 and Figure 8 An operation of selecting pixels during a compressive sensing operation of an image sensor according to a third embodiment of the present invention is shown.

[0017] Fig. 9 Pixels selected from a pixel group in consideration of a rule related to a color filter according to an embodiment of the present invention are shown. DETAILED DESCRIPTION

[0018] The various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. However, the present invention can be embodied in different forms, and the present invention should not be understood to be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be detailed and complete, and the scope of the present invention will be fully conveyed to those skilled in the art. Throughout this disclosure, throughout the various figures and embodiments of the present invention, the same reference numerals refer to the same parts.

[0019] Figure 1 is a block diagram illustrating an image sensor 100 according to an embodiment of the present invention.

[0020] refer to Figure 1 , the image sensor 100 may include a pixel array 110 , a row decoder 120 , a readout circuit 130 , a compression controller 140 , and an image processor 150 .

[0021] The pixel array 110 may include a plurality of pixels formed into an array including a plurality of rows and a plurality of columns. The pixels may output pixel signals based on the sensed light.

[0022] The row decoder 120 may select pixels of the pixel array 110 for each row and control the operation. Under the control of the row decoder 120, pixels of one row at a time may output pixel signals to the readout circuit 130.

[0023] The readout circuit 130 may perform analog-to-digital conversion to convert a pixel signal, which is an analog signal output from the pixel array 110, into a digital signal. The result of converting the pixel signal into a digital signal may be output as an image. The readout circuit 130 may perform analog-to-digital conversion on the pixel signals of the pixels of all columns of the selected row at a time.

[0024] During a normal sensing operation of the image sensor 100, the pixels of the pixel array 110 may be read out on a row unit basis. Pixel signals may be output from all pixels in a first row of the pixel array 110, and the pixel signals of all pixels in the first row may be analog-to-digital converted by the readout circuit 130. Subsequently, pixel signals may be output from all pixels in a second row of the pixel array 110, and the pixel signals of all pixels in the second row may be analog-to-digital converted by the readout circuit 130. Similarly, in other rows, likewise, the pixel signals of all pixels may be transmitted to the readout circuit 130 on a row unit basis, and all pixel signals in the corresponding rows may be analog-to-digital converted by the readout circuit 130.

[0025] The compression controller 140 may control the compressive sensing operation of the image sensor 100. Here, the compressive sensing operation may refer to an operation of reading out some pixels (e.g., 1 / 4 or 1 / 8 of all pixels) of the pixel array 110 instead of reading out all pixels. The compressive sensing operation may be performed by the compression controller 140 controlling the readout circuit 130. The compressive sensing operation will be described in detail below.

[0026] The image processor 150 may process the image IMG output from the readout circuit 130 to generate a processed image IMG_PROCESSED. The image processor 150 may perform various operations to improve image quality. Specifically, the image processor 150 may generate a high-resolution image IMG_PROCESSED by processing a low-resolution image IMG generated during a compressed sensing operation. Although the image processor 150 is shown herein to be included in the image sensor 100, the image processor 150 may exist outside the image sensor 100.

[0027] Figure 2 and Figure 3 A rule for selecting pixels to be read out among pixels of the pixel array 110 when the image sensor 100 performs a compressive sensing operation according to an embodiment of the present invention is shown.

[0028] The rules for selecting pixels to be read out from pixel array 110 during a compressed sensing operation are as shown below (1) to (3).

[0029] (1) When a compressed sensing operation is performed at a compression rate of 1 / N, the pixel array may be divided into N (row) x N (column) pixel groups. That is, each pixel group may be an array of NxN pixels. A pixel group may be divided into N sub-pixel groups, each sub-pixel group containing N pixels.

[0030] Figure 2 A pixel group 200 is shown when the compression rate is 1 / 4. Figure 2 , the pixel group 200 may include 16 pixels arranged in 4 (rows) x 4 (columns). In addition, it can be seen that one pixel group 200 is divided into four sub-pixel groups 211 to 214, each of which includes four pixels. The pixel array 110 may include a plurality of sub-pixel groups such as Figure 2 For example, when the pixel array 110 is formed by 1024 (rows) x 1024 (columns), the pixel array 110 may include 655536 pixels. Figure 2 The pixel group 200 shown in (655536=1024*1024 / 16).

[0031] Figure 3FIG. 3 shows a pixel group 300 when the compression rate is 1 / 8 according to an embodiment of the present invention. Figure 3 , a pixel group may include 64 pixels arranged in 8 (rows) x 8 (columns). In addition, it can be seen that a pixel group 300 is divided into 8 sub-pixel groups 311 to 318, each sub-pixel group includes 8 pixels. The pixel array 110 may include a plurality of sub-pixel groups such as Figure 3 For example, when the pixel array 110 is formed by 1024 (rows) x 1024 (columns), the pixel array 110 may include 16384 pixels. Figure 3 The pixel group 300 shown in (16384=1024*1024 / 64).

[0032] (2) In one pixel group, no more than two pixels are selected in one row, and no more than two pixels are selected in one column.

[0033] exist Figure 2 The selected pixels in the pixel group 200 are marked with circles, and it can be seen that, in the pixel group 200, only one pixel is selected in a row, and only one pixel is selected in a column.

[0034] exist Figure 3 In the pixel group 300, similarly, the selected pixels are also marked with circles, and it can be seen that in the pixel group 300, only one pixel is selected in a row and only one pixel is selected in a column.

[0035] It can be seen that in Figure 2 and Figure 3 In both, 2 or more pixels are not selected in a row, and 2 or more pixels are not selected in a column.

[0036] (3) Do not select more than two pixels in one sub-pixel group.

[0037] refer to Figure 2 and Figure 3 , it can be seen that only one pixel is selected in each of the sub-pixel groups 211 to 214 and 311 to 318.

[0038] Below, the process of selecting pixels based on the rules of (1) to (3) can be described.

[0039] Figure 4 An operation of selecting pixels during a compressive sensing operation of the image sensor 100 according to the first embodiment of the present invention is shown. Here, an operation performed when the image sensor 100 performs a compressive sensing operation at a compression rate of 1 / 4 will be described.

[0040] exist Figure 4In (a-1), the selectable pixels in the first row of the pixel group 200 are marked with slashes. In the first row, one pixel among the four pixels can be selected. The compression controller 140 can control the readout circuit 130 to randomly select one pixel among the four pixels in the first row during the readout operation of the first row of the pixel group 200 and read out the selected pixel.

[0041] exist Figure 4 In (a-2) of FIG. 2 , the pixels selected from the first row of the pixel group 200 are circled. It can be seen that the pixels in the third column are selected as a result of random selection among the four pixels marked with diagonal lines in (a-1).

[0042] exist Figure 4 In (b-1), the selectable pixels in the second row of the pixel group 200 are marked with slashes. In the second row, one pixel among the pixels of another sub-pixel group 211 (not the sub-pixel group 212 to which the pixel selected in the first row belongs) may be selected. The compression controller 140 may control the readout circuit 130 to randomly select one of the two selectable pixels and read out the selected pixel.

[0043] exist Figure 4 In (b-2) of FIG. 2 , the pixels selected from the second row of the pixel group 200 are circled. It can be seen that the pixel in the first column is selected as a result of random selection among the two pixels marked with diagonal lines in (b-1).

[0044] exist Figure 4 In (c-1), the selectable pixels in the third row of the pixel group 200 are marked with slashes. In the third row, among the four columns, two columns other than the same column as the column of the pixel selected in the first row and the same column as the column of the pixel selected in the second row can be selected. The compression controller 140 can control the readout circuit 130 to randomly select one of the two selectable pixels and read out the selected pixel.

[0045] exist Figure 4 In (c-2) of FIG. 2 , the pixels selected from the third row of the pixel group 200 are circled. It can be seen that the pixel in the fourth column is selected as a result of random selection among the two pixels marked with diagonal lines shown in (c-1).

[0046] exist Figure 4 In (d-1), the selectable pixels in the fourth row of the pixel group are marked with slashes. Because a column different from the pixels selected in the previous row is selectable, it can be seen that only the second column is selectable. The compression controller 140 can control the readout circuit 130 to select the pixels of the selectable second column and read out the selected pixels.

[0047] exist Figure 4 In (d-2), the selected pixels in the fourth row of the pixel group are marked with circles.

[0048] When passing Figure 4 When selecting and reading out pixels by the process of , only one column can be read out in one row in the pixel group 200. Therefore, the amount of current consumed by the readout circuit 130 for analog-to-digital conversion of each row can be uniformly reduced to 1 / 4. In addition, because a pixel is selected from each of the sub-pixel groups 211 to 214, the image processor 150 can use the selected pixel as a representative pixel of the corresponding sub-pixel group to facilitate image processing.

[0049] Figure 5 and Figure 6 An operation of selecting pixels during a compressive sensing operation of the image sensor 100 according to the second embodiment of the present invention is shown. Here, an operation will be described in which the image sensor 100 performs a compressive sensing operation at a compression rate of 1 / 8 and a subpixel group is formed of 4 (rows) x 2 (columns).

[0050] exist Figure 5 In (a-1), selectable pixels in the first row of the pixel group 300 are marked with slashes. In the first row, one pixel among the eight pixels can be selected. The compression controller 140 can control the readout circuit 130 to randomly select one pixel among the eight pixels in the first row during the readout operation of the first row of the pixel group 300 and read out the selected pixel.

[0051] exist Figure 5 In (a-2) of FIG. 3 , the pixels selected from the first row of the pixel group 300 are circled. It can be seen that the pixels in the sixth column are selected as a result of random selection among the eight pixels marked with diagonal lines shown in (a-1).

[0052] exist Figure 5 In (b-1), the selectable pixels in the second row of the pixel group 300 are marked with slashes. In the second row, one pixel among the pixels of the sub-pixel groups 311, 312, and 314 (rather than the sub-pixel group 313 to which the pixel selected in the first row belongs) can be selected. The compression controller 140 can control the readout circuit 130 to randomly select one pixel among the 6 pixels shown in (b-1) and read out the selected pixel.

[0053] exist Figure 5 In (b-2) of FIG. 3 , the pixels selected in the second row of the pixel group 300 are circled. It can be seen that the pixels in the fourth column are selected as a result of random selection among the six pixels marked with diagonal lines shown in (b-1).

[0054] exist Figure 5 In (c-1), the selectable pixels in the third row of the pixel group 300 are marked with slashes. In the third row, one pixel among the pixels of the subpixel groups 311 and 314 (rather than the subpixel group 313 to which the pixel selected in the first row belongs and the subpixel group 312 to which the pixel selected in the second row belongs) may be selected. The compression controller 140 may control the readout circuit 130 to randomly select one pixel among the four pixels shown in (c-1) and read out the selected pixel.

[0055] exist Figure 5 In (c-2) of FIG. 3 , the pixels selected from the third row of the pixel group 300 are circled. It can be seen that the pixel in the seventh column is selected as a result of random selection among the four pixels marked with diagonal lines shown in (c-1).

[0056] exist Figure 5 In (d-1), the selectable pixels in the fourth row of the pixel group 300 are marked with diagonal lines. In the fourth row, one pixel among the pixels of the subpixel group 311 (rather than the subpixel group 313 to which the pixel selected in the first row belongs, the subpixel group 312 to which the pixel selected in the second row belongs, and the subpixel group 314 to which the pixel selected in the third row belongs) may be selected. The compression controller 140 may control the readout circuit 130 to randomly select one pixel among the two pixels marked with diagonal lines in (d-1) and read out the selected pixel.

[0057] exist Figure 5 In (d-2) of FIG. 3 , the pixels selected in the fourth row of the pixel group 300 are circled. It can be seen that the pixel in the first column is selected as a result of random selection among the two pixels marked with diagonal lines shown in (d-1).

[0058] exist Figure 6 In (e-1), selectable pixels in the fifth row of the pixel group 300 are marked with slashes. In the fifth row, one of the columns other than the columns to which the pixels selected in the first to fourth rows belong may be selected. The compression controller 140 may control the readout circuit 130 to randomly select a pixel of one of the four columns shown in (e-1) and read out the selected pixel.

[0059] exist Figure 6 In (e-2) of FIG. 3 , the pixels selected in the fifth row of the pixel group 300 are circled. It can be seen that the pixels in the third column are selected as a result of random selection among the four pixels marked with diagonal lines in (e-1).

[0060] exist Figure 6 In (f-1), selectable pixels in the sixth row of the pixel group 300 are marked with slashes. In the sixth row, one of the columns other than the column of the subpixel group 316 to which the pixel selected in the fifth row belongs and the columns to which the pixels selected in the first to fourth rows belong may be selected. The compression controller 140 may control the readout circuit 130 to randomly select a pixel of one of the three columns marked with slashes in (f-1) and read out the selected pixel.

[0061] exist Figure 6 In (f-2) of FIG. 3 , the pixels selected in the sixth row of the pixel group 300 are circled. It can be seen that the pixels in the second column are selected as a result of random selection among the three pixels marked with diagonal lines in (f-1).

[0062] exist Figure 6 In (g-1), selectable pixels in the seventh row of the pixel group 300 are marked with diagonal lines. In the seventh row, one of the columns other than the columns of the sub-pixel groups 315 and 316 to which the pixels selected in the fifth row and the pixels selected in the sixth row belong and the columns to which the pixels selected in the first to fourth rows belong may be selected. The compression controller 140 may control the readout circuit 130 to randomly select a pixel of one of the two columns marked with diagonal lines in (g-1) and read out the selected pixel.

[0063] exist Figure 6 In (g-2) of FIG. 3 , the pixels selected in the seventh row of the pixel group 300 are circled. It can be seen that the pixel in the eighth column is selected as a result of random selection among the two pixels marked with diagonal lines in (g-1).

[0064] exist Figure 6 In (h-1), the selectable pixels in the eighth row of the pixel group 300 are marked with slashes. In the eighth row, since a column different from the column of the pixel selected in the previous row can be selected, it can be seen that only the fifth column is selectable. The compression controller 140 can control the readout circuit 130 to select the pixel of the selectable fifth column and read out the selected pixel.

[0065] exist Figure 6 In (h-2) of FIG. 3 , the pixels selected in the eighth row of the pixel group 300 are marked with circles.

[0066] When passing Figure 5 and Figure 6When selecting and reading out pixels by the process of , only one column can be read out from one row in the pixel group 300. Therefore, the amount of current consumed by the readout circuit 130 for analog-to-digital conversion for each row can be uniformly reduced to 1 / 8. In addition, since one pixel is selected from each of the sub-pixel groups 311 to 318, the image processor 150 can easily process an image by using the selected pixel as a representative pixel of the corresponding sub-pixel group.

[0067] Figure 7 and Figure 8 An operation of selecting pixels during a compressive sensing operation of the image sensor 100 according to the third embodiment of the present invention is shown. Here, an operation will be described in which the image sensor 100 performs a compressive sensing operation at a compression rate of 1 / 8, so that a pixel group is formed of 8 (rows) x 8 (columns), and each pixel group includes 8 sub-pixel groups, each of which is formed of 2 (rows) x 4 (columns).

[0068] exist Figure 7 In (a-1), the selectable pixels in the first row of the pixel group are marked with slashes. In the first row, one pixel among the eight pixels can be selected. The compression controller 140 can control the readout circuit 130 to randomly select one pixel among the eight pixels in the first row during the readout operation of the first row of the pixel group and read out the selected pixel.

[0069] exist Figure 7 In (a-2) of FIG. 1 , the pixels selected from the first row of the pixel group are marked with circles. It can be seen that the pixels in the fourth column are selected as a result of random selection among the eight pixels marked with diagonal lines in (a-1).

[0070] exist Figure 7 In (b-1), the selectable pixels in the second row of the pixel group are marked with diagonal lines. In the second row, one pixel among the pixels of the subpixel group 712 other than the subpixel group 711 to which the pixel selected in the first row belongs can be selected. The compression controller 140 can control the readout circuit 130 to randomly select one pixel among the four pixels marked with diagonal lines in (b-1) and read out the selected pixel.

[0071] exist Figure 7 In (b-2) of FIG. 1 , the pixels selected in the second row of the pixel group are marked with circles. It can be seen that the pixel in the sixth column is selected as a result of random selection among the four pixels marked with diagonal lines in (b-1).

[0072] exist Figure 7In (c-1), selectable pixels in the third row of the pixel group are marked with slashes. In the third row, one of the columns other than the columns to which the pixels selected in the first and second rows belong may be selected. The compression controller 140 may control the readout circuit 130 to randomly select one of the six pixels marked with slashes in (c-1) and read out the selected pixel.

[0073] exist Figure 7 In (c-2) of FIG. 1 , the pixels selected in the third row of the pixel group are marked with circles. It can be seen that the pixels in the fifth column are selected as a result of random selection among the six pixels marked with diagonal lines in (c-1).

[0074] exist Figure 7 In (d-1), the selectable pixels in the fourth row of the pixel group are marked with slashes. In the fourth row, one column can be selected except the column of the subpixel group 714 to which the pixel selected in the third row belongs and the column to which the pixels selected in the first row and the second row belong. The compression controller 140 can control the readout circuit 130 to randomly select one pixel among the three pixels marked with slashes in (d-1) and read out the selected pixel.

[0075] exist Figure 7 In (d-2) of FIG. 1 , the pixels selected in the fourth row of the pixel group are circled. It can be seen that the pixels in the first column are selected as a result of random selection among the three pixels marked with diagonal lines in (d-1).

[0076] exist Figure 8 In (e-1), selectable pixels in the fifth row of the pixel group are marked with slashes. In the fifth row, one of the columns other than the columns to which the pixels selected in the first to fourth columns belong may be selected. The compression controller 140 may control the readout circuit 130 to randomly select one of the four pixels marked with slashes in (e-1) and read out the selected pixel.

[0077] exist Figure 8 In (e-2) of FIG. 1 , the pixels selected in the fifth row of the pixel group are marked with circles. It can be seen that the pixels in the second column are selected as a result of random selection among the four pixels marked with diagonal lines in (e-1).

[0078] exist Figure 8In (f-1), the selectable pixels in the sixth row of the pixel group are marked with slashes. In the sixth row, one of the columns other than the column of the subpixel group 715 to which the pixel selected in the fifth row belongs and the columns to which the pixels selected in the first to fourth rows belong may be selected. The compression controller 140 may control the readout circuit 130 to randomly select one of the two pixels marked with slashes in (f-1) and read out the selected pixel.

[0079] exist Figure 8 In (f-2) of FIG. 1 , the pixel selected in the sixth row of the pixel group is marked with a circle. It can be seen that the pixel in the eighth column is selected as a result of random selection among the two pixels marked with diagonal lines in (f-1).

[0080] exist Figure 8 In (g-1), the selectable pixels in the seventh row of the pixel group are marked with slashes. In the seventh row, one of the columns other than the columns to which the pixels selected in the first to sixth columns belong may be selected. The compression controller 140 may control the readout circuit 130 to randomly select one of the two pixels marked with slashes in (g-1) and read out the selected pixel.

[0081] exist Figure 8 In (g-2) of FIG. 1 , the pixel selected in the seventh row of the pixel group is marked with a circle. It can be seen that the pixel in the seventh column is selected as a result of random selection among the two pixels marked with diagonal lines in (g-1).

[0082] exist Figure 8 In (h-1), the selectable pixels in the eighth row of the pixel group are marked with slashes. In the eighth row, one of the columns other than the columns to which the pixels selected in the first to seventh rows belong may be selected. The compression controller 140 may control the readout circuit 130 to select a pixel in the selectable fourth column and read out the selected pixel.

[0083] exist Figure 8 In (h-2), the selected pixels in the eighth row of the pixel group are marked with circles.

[0084] exist Figure 4 , a process of selecting pixels to be read out when the value of N is 4 in the case where the compression rate of the compressive sensing operation is 1 / N is described, and Figures 5 to 8, a process of selecting pixels to be read out when the value of N is 8 is described. Even when the value of N is different from this, the same rule as described above can be applied. That is, when selecting pixels to be read out from the Kth row within the pixel group (where K is an integer equal to or greater than 2 and equal to or less than N), one pixel can be selected that is not included in the sub-pixel group to which the pixels selected in the first to K-1th rows belong and is not included in the column to which the pixels selected in the first to K-1th rows belong.

[0085] In order to consider the color filter when selecting pixels during the compressed sensing operation, one more rule may be added to the rules (1) to (3) described above.

[0086] (4) Pixels of the same color may not be selected in consecutive rows.

[0087] That is, it may be necessary to select pixels of different colors in consecutive rows. Fig. 9 An example of selecting pixels from the pixel group 300 by further considering rule (4) is shown in FIG. Fig. 9 , which shows pixels selected from pixel group 300 according to an embodiment of the present disclosure taking into account rules related to color filters, it can be seen that rules (1) to (3) are followed and rule (4) of selecting pixels of different colors in consecutive rows is maintained.

[0088] According to an embodiment of the present disclosure, a portion of pixels may be randomly selected and sensed in an image sensor.

[0089] Effects expected to be obtained in the embodiments of the present disclosure are not limited to the effects described above, and other effects not described above may also be clearly understood by those skilled in the art to which the present invention pertains.

[0090] Although the present invention has been described with respect to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention as defined in the appended claims. Furthermore, the embodiments may be combined to form additional embodiments.

Claims

1. A method for operating an image sensor, wherein the image sensor is provided with a 4-row x 4-column pixel group, the 4-row x 4-column pixel group includes 4 sub-pixel groups, each sub-pixel group includes 4 pixels of 2 rows x 2 columns, the method comprising: selecting and reading out a first pixel among four pixels in a first row of the pixel group; In a second row of the pixel group, selecting and reading out a second pixel from a sub-pixel group other than the sub-pixel group including the first pixel; In a third row of the pixel group, selecting and reading out a third pixel from a column other than a column including the first pixel and a column including the second pixel; as well as In a fourth row of the pixel group, a fourth pixel is selected and read out from columns other than a column including the first pixel, a column including the second pixel, and a column including the third pixel.

2. The method according to claim 1, in, The first pixel is included in a first sub-pixel group among the four sub-pixel groups, The second pixel is included in the second sub-pixel group of the four sub-pixel groups. The third pixel is included in the third sub-pixel group of the four sub-pixel groups, and The fourth pixel is included in the fourth sub-pixel group among the four sub-pixel groups.

3. The method according to claim 2, wherein: Among the first to fourth pixels, pixels in adjacent rows are pixels of different colors.

4. A method for operating an image sensor, wherein the image sensor is provided with 8 rows x 8 columns of pixel groups, wherein the 8 rows x 8 columns of pixel groups include 8 sub-pixel groups, each sub-pixel group includes 8 pixels of 4 rows x 2 columns, the method comprising: selecting and reading out a first pixel among eight pixels in a first row of the pixel group; In a second row of the pixel group, selecting and reading out a second pixel from a sub-pixel group other than the sub-pixel group including the first pixel; In a third row of the pixel groups, selecting and reading out a third pixel from the sub-pixel groups other than the sub-pixel group including the first pixel and the sub-pixel group including the second pixel; and In a fourth row of the pixel groups, a fourth pixel is selected and read out from the sub-pixel groups other than the sub-pixel group including the first pixel, the sub-pixel group including the second pixel, and the sub-pixel group including the third pixel.

5. The method according to claim 4, further comprising: In a fifth row of the pixel group, selecting and reading out a fifth pixel from columns other than a column including the first pixel, a column including the second pixel, a column including the third pixel, and a column including the fourth pixel; In a sixth row of the pixel group, a sixth pixel is selected and read out from columns other than a column of a subpixel group including the fifth pixel, a column including the first pixel, a column including the second pixel, a column including the third pixel, and a column including the fourth pixel; In a seventh row of the pixel group, a seventh pixel is selected and read out from columns other than a column including a subpixel group of the fifth pixel, a column including a subpixel group of the sixth pixel, a column including the first pixel, a column including the second pixel, a column including the third pixel, and a column including the fourth pixel; as well as In an eighth row of the pixel group, an eighth pixel is selected and read out from columns other than a column including the first pixel to a column including the seventh pixel.

6. The method according to claim 5, wherein: The first to eighth pixels are included in different sub-pixel groups in the pixel group.

7. The method according to claim 6, wherein: Among the first to eighth pixels, pixels in adjacent rows are pixels of different colors.

8. A method for operating an image sensor, wherein the image sensor is provided with 8 rows x 8 columns of pixel groups, the 8 rows x 8 columns of pixel groups comprising 8 sub-pixel groups, each sub-pixel group comprising 8 pixels of 2 rows x 4 columns, the method comprising: selecting and reading out a first pixel among eight pixels in a first row of the pixel group; In a second row of the pixel group, selecting and reading out a second pixel from a sub-pixel group other than the sub-pixel group including the first pixel; In a third row of the pixel group, selecting and reading out a third pixel from a column other than a column including the first pixel and a column including the second pixel; as well as In a fourth row of the pixel group, a fourth pixel is selected and read out from columns other than a column of a sub-pixel group including the third pixel, a column including the first pixel, and a column including the second pixel.

9. The method according to claim 8, further comprising: In a fifth row of the pixel group, selecting and reading out a fifth pixel from columns other than a column including the first pixel, a column including the second pixel, a column including the third pixel, and a column including the fourth pixel; In a sixth row of the pixel group, a sixth pixel is selected and read out from columns other than a column of a subpixel group including the fifth pixel, a column including the first pixel, a column including the second pixel, a column including the third pixel, and a column including the fourth pixel; In a seventh row of the pixel group, selecting and reading out a seventh pixel from columns other than a column including the first pixel, a column including the second pixel, a column including the third pixel, a column including the fourth pixel, a column including the fifth pixel, and a column including the sixth pixel; as well as In an eighth row of the pixel group, an eighth pixel is selected and read out from columns other than a column including the first pixel to a column including the seventh pixel.

10. The method according to claim 9, wherein: The first to eighth pixels are included in different sub-pixel groups in the pixel group.

11. The method according to claim 10, wherein: Among the first to eighth pixels, pixels in adjacent rows are pixels of different colors.

12. A method for operating an image sensor, the image sensor being provided with an N-row×N-column pixel group, the N-row×N-column pixel group comprising N sub-pixel groups, each sub-pixel group comprising N adjacent pixels, wherein N is an integer equal to or greater than 4, the method comprising: selecting and reading out a first pixel among N pixels in a first row of the pixel group; In a second row of the pixel group, selecting and reading out a second pixel from a sub-pixel group other than the sub-pixel group including the first pixel; Among the N pixels in the third row of the pixel group, selecting and reading out a third pixel that is not a pixel included in the subpixel group including the first pixel, a pixel included in the subpixel group including the second pixel, a pixel of a column including the first pixel, and a pixel of a column including the second pixel; as well as Among the N pixels in the fourth row of the pixel group, a fourth pixel is selected and read out, and the fourth pixel is not a pixel included in the sub-pixel group including the first pixel, a pixel included in the sub-pixel group including the second pixel, a pixel included in the sub-pixel group including the third pixel, a pixel in the column including the first pixel, a pixel in the column including the second pixel, and a pixel in the column including the third pixel.

13. The method according to claim 12, further comprising: Among the N pixels in the Kth row of the pixel group, the Kth pixel is selected and read out, and the Kth pixel is not a pixel included in the sub-pixel group including the first pixel to the sub-pixel group including the K-1th pixel and a pixel in the column including the first pixel to the column including the K-1th pixel, where K is an integer equal to or greater than 5 and equal to or less than N.

14. The method according to claim 13, wherein: The first to K-th pixels are included in different sub-pixel groups and different columns in the pixel group.

15. The method according to claim 14, wherein: Among the first to K-th pixels, pixels in adjacent rows are pixels of different colors.

16. An image sensor, comprising: A pixel array comprising N rows x N columns of pixel groups, each pixel group comprising N sub-pixel groups, each sub-pixel group comprising N adjacent pixels, wherein N is an integer equal to or greater than 4; a row decoder adapted to select pixels of the pixel array for each row and to control operation; a readout circuit adapted to perform analog-to-digital conversion on pixel signals output by pixels in a row selected by the row decoder in the pixel array; as well as a compression controller adapted to control the readout circuit to read out a portion of, but not all, the columns of the pixel array during a compressive sensing operation; Wherein, the compression controller controls the readout circuit to: During a readout operation for a first row of the pixel group, selecting and reading out a first pixel among the N pixels; During a readout operation for a second row of the pixel group, a second pixel is selected and read out from a sub-pixel group other than the sub-pixel group including the first pixel.

17. The image sensor according to claim 16, wherein: The compression controller controls the readout circuit to: During a readout operation for a third row of the pixel group, selecting and reading out a third pixel that is not a pixel included in the subpixel group including the first pixel, a pixel included in the subpixel group including the second pixel, a pixel of a column including the first pixel, and a pixel of a column including the second pixel; as well as During a readout operation on a fourth row of the pixel group, a fourth pixel is selected and read out, and the fourth pixel is not a pixel included in the sub-pixel group including the first pixel, a pixel included in the sub-pixel group including the second pixel, a pixel included in the sub-pixel group including the third pixel, a pixel of a column including the first pixel, a pixel of a column including the second pixel, and a pixel of a column including the third pixel.

18. The image sensor according to claim 17, wherein: The compression controller controls the readout circuit to further select and read out the Kth pixel during a readout operation on the Kth row of the pixel group, and the Kth pixel is not a pixel included in the sub-pixel group including the first pixel to the sub-pixel group including the K-1th pixel and a pixel in the column including the first pixel to the column including the K-1th pixel, where K is an integer equal to or greater than 5 and equal to or less than N.

19. The image sensor of claim 18, further comprising an image processor adapted to generate a high-resolution image by processing a low-resolution image generated via the compressive sensing operation.

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