On-chip Column Windowing Data Extraction Method for a Bidirectional Readout Image Sensor

Abstract

An on-chip column windowing data extraction method for a bidirectional readout image sensor, comprising the steps of: 1. Define a start position register Start_Column and an end position register End_Column; 2. Determine the windowing range of the column windowing operation, write the start column position information into Start_Column, and write the end column position information into End_Column. For each column control circuit, perform the operations in steps 3 to 6; 3. Compare the position label information in Start_Column and End_Column with the position label information in the position register of the current column control circuit respectively to determine whether the column windowing instruction is valid for the current column control circuit; 4. Determine the start column number and the end column number of the current column control circuit participating in the windowing; 5. Determine the column control circuit where the start column number in the windowing range is located and its start column number for the current column control circuit; 6. Determine the column control circuit where the end column number in the windowing range is located and its stop column number for the current column control circuit; 7. Extract the column pixel data corresponding to the externally input windowing range.

Description

Technical Field

[0001] The present invention belongs to the field of column pixel data processing of image sensors, and is particularly applicable to column selection positioning of large-area, high-speed image sensors without on-chip storage. Background Art

[0002] High-speed, large-area image sensors are characterized by a large amount of data. A single data transmission port cannot meet the data rate transmission requirements. Data is generally sent in parallel through multiple transmission interfaces. At the same time, to match high-speed data transmission interfaces, the data of the image sensor also needs to be segmented into corresponding independent circuits for data processing. The data processing circuits of the entire chip are independent of each other and execute in parallel.

[0003] The data reading principle of a global shutter image sensor is generally to read all column data row by row, that is, all column data of one row are read out simultaneously, and multiple image processing circuits are required to process the data in parallel. To implement random column windowing on the chip, that is, to open a small window in a certain area of the image and output the column pixel data of the windowed area, there are two methods. The commonly used method is to embed a memory inside the sensor to store all column data and select data according to requirements; another method is to embed the column windowing algorithm into each image processing circuit, and locate the data that needs to be output within this circuit according to the column windowing information; however, the current column windowing algorithms applicable to large-area image sensors are not yet mature.

[0004] The pixels and column readout circuits inside the image sensor occupy most of the chip area. Due to the large area, high design difficulty, and high IP cost of the on-chip memory, the method of embedding a memory inside the image sensor has a relatively high cost. Therefore, it is necessary to design instructions and algorithms applicable to flexible column windowing of the entire chip to control the accurate and efficient output of column pixel data. Summary of the Invention

[0005] The technical problem solved by the present invention is: overcoming the deficiencies of the prior art, providing a method for extracting on-chip column windowing data of a bidirectional readout image sensor, and quickly selecting corresponding column pixel data for output.

[0006] The technical solution adopted by the present invention is a method for extracting on-chip column windowing data of a bidirectional readout image sensor, applicable to an image sensor in which a pixel array is read out bidirectionally through an odd column control circuit and an even column control circuit. The odd column control circuit controls the downward output of data of columns 0, 2,... M-2 in the pixel array, and the even column control circuit controls the upward output of data of columns 1, 3,... M-1 in the pixel array, where M is the total number of columns of all column data processed by the image sensor; in each column control circuit, there is an inherent column control circuit position register, which contains the parity information and position label information of the control circuit itself; and it is characterized by including the following steps:

[0007] Step 1: Define the start column register Start_Column and the end column register End_Column for the D - bit window opening. Start_Column and End_Column are divided into three parts: odd - even identification, internal column selection information of the column control circuit, and position label information of the column control circuit. Among them: The position label information of the column control circuit in Start_Column stores the number of the column control circuit where output starts, and the internal column selection information in Start_Column stores the starting column number in the column control circuit where output starts; The position label information of the column control circuit in End_Column stores the number of the column control circuit where output ends, and the internal column selection information in End_Column stores the stopping column number in the column control circuit where output ends.

[0008] Step 2: Receive the window opening range of the external input column window opening operation, including the starting column number and the ending column number. Convert the starting column number through the number system and write it into Start_Column to obtain the starting column window opening instruction. Convert the ending column number through the number system and write it into End_Column to obtain the ending column window opening instruction.

[0009] For each column control circuit, perform the operations in Step 3 to Step 6:

[0010] Step 3: If the position label of the column control circuit itself is less than the position label of the column control circuit in the starting column window opening instruction, it means the starting column window opening instruction is invalid for the current column control circuit, and there is no output from the current column control circuit; If the position label of the current column control circuit is greater than the position label of the column control circuit in the ending column window opening instruction, it means the ending column window opening instruction is invalid for the current column control circuit, and there is no output from the current column control circuit; If the position label of the current column control circuit is between the position labels of the column control circuits in the starting column window opening instruction and the ending column window opening instruction, go to Step 4; If the position label of the current column control circuit is equal to the position label of the column control circuit in the starting column window opening instruction, go to Step 5; If the position label of the current column control circuit is equal to the position label of the column control circuit in the ending column window opening instruction, go to Step 6;

[0011] Step 4: Determine the starting column number and the ending column number for which the current column control circuit participates in the window opening: The starting column number of the current column control circuit is column 0, and the stopping column number is column 2k - 1;

[0012] Step 5: Determine that the current column control circuit is the column control circuit where the starting column number in the window opening range is located, and its starting column number;

[0013] Step 6: Determine that the current column control circuit is the column control circuit where the ending column number in the window opening range is located, and its stopping column number;

[0014] Step 7: Extract the column pixel data corresponding to the externally input windowing range according to the judgments in Steps 3 to 6.

[0015] Further, there are a total of 2E column control circuits in the image sensor. The odd-column control circuits and even-column control circuits are numbered from 0 to E - 1; the number of column data columns m controlled by each column control circuit is 2 k , and the internal column numbers of each column control circuit are all 0, 1, …, 2 k -1. The total number of pixel columns that need to be controlled by the odd-column control circuits and even-column control circuits with the same number is 2m; the total number of columns M of all column pixels that the image sensor can process is 2Em, and the column numbers are 0, 1, …, 2Em - 1;

[0016] where: k corresponds to the number of bits of the column selection information inside the column control circuit in Start_Column and End_Column.

[0017] Further, the data partitioning method of the Start_Column and End_Column is as follows:

[0018] a. Start_Column[0] and End_Column[0] are parity identification bits. 0 indicates an odd-column control circuit, and the data is output downward; 1 indicates an even-column control circuit, and the data is output upward;

[0019] b. Start_Column[k:1] represents the column number inside the column control circuit of the start column, and End_Column[k:1] represents the column number inside the column control circuit of the end column. The range that Start_Column[k:1] and End_Column[k:1] can represent is (0)2 to (2 k -1)2;

[0020] c. Start_Column[D - 1:k + 1] represents the number of the column control circuit where the start column is located, and End_Column[D - 1:k + 1] is the number of the column control circuit where the end column is located. The number of column control circuits that Start_Column[D - 1:k + 1] and End_Column[D - 1:k + 1] can represent satisfies:

[0021]

[0022] Further, the bit width D of the column window start position register Start_Column and the column window end position register End_Column is:

[0023]

[0024] Further, the starting column number and the ending column number described in step 2 are respectively converted into corresponding D-bit binary numbers. When the number of bits is less than D, 0s are filled in the high positions. The D-bit binary number of the starting column number is written into bits D-1 to 0 of Start_Column in order from the high position to the low position to obtain the starting column windowing instruction, and the D-bit binary number of the ending column number is written into bits D-1 to 0 of End_Column in order from the high position to the low position to obtain the ending column windowing instruction.

[0025] Further, bits [D-1:k+1] of the starting column windowing instruction represent the number of the column control circuit where the starting column number is located, bits [k:1] of the starting column windowing instruction represent the column number in the column control circuit where the starting column number is located, and bit [0] of the starting column windowing instruction represents whether the column control circuit where the starting column number is located is an odd column control circuit or an even column control circuit; bits [D-1:k+1] of the ending column windowing instruction represent the number of the column control circuit where the ending column number is located, bits [k:1] of the ending column windowing instruction represent the column number in the column control circuit where the ending column number is located, and bit [0] of the ending column windowing instruction represents whether the column control circuit where the ending column number is located is an odd column control circuit or an even column control circuit.

[0026] Further, the method for determining the column control circuit where the starting column number in step 5 is located and its starting column number is as follows:

[0027] Compare bit [0] of the starting column windowing instruction with the parity identification bit in the current column control circuit position register:

[0028] If the parity identification bit in the current column control circuit position register is the same as bit [0] of the starting column windowing instruction, then the current column control circuit is the column control circuit where the starting column number is located, and the starting column number is bits [k:1] of the starting column windowing instruction.

[0029] If the parity identification bit in the current column control circuit position register is different from bit [0] of the starting column windowing instruction, then the current column control circuit is not the column control circuit where the starting column number is located, and the determination method of the starting column number is as follows:

[0030] If the parity identification bit in the current column control circuit position register is 1 and bit [0] of the starting column windowing instruction is 0, then the starting column number of the current column control circuit is bits [k:1] of the starting column windowing instruction;

[0031] If the parity identification bit in the current column control circuit position register is 0 and bit [0] of the starting column windowing instruction is 1, then the starting column number of the current column control circuit is bits [k:1] of the starting column windowing instruction + 1.

[0032] Further, the determination method of the column control circuit where the ending column number in step 6 is located and its stop column number is as follows:

[0033] Compare the [0] bit of the end column windowing instruction with the parity identification bit in the current column control circuit position register:

[0034] If the parity identification bit in the current column control circuit position register is the same as the [0] bit of the end column windowing instruction, then the current column control circuit is the column control circuit where the end column number is located, and the stop column number is the [k:1] bits of the end column windowing instruction.

[0035] If the parity identification bit in the current column control circuit position register is different from the [0] bit of the end column windowing instruction, then the current column control circuit is not the column control circuit where the end column number is located, and the determination method of the stop column number is as follows:

[0036] If the parity identification bit in the current column control circuit position register is 1 and the [0] bit of the end column windowing instruction is 0, then the stop column number of the current column control circuit is the [k:1] bits of the end column windowing instruction - 1;

[0037] If the parity identification bit in the current column control circuit position register is 0 and the [0] bit of the end column windowing instruction is 1, then the stop column number of the current column control circuit is the [k:1] bits of the end column windowing instruction.

[0038] The beneficial effects of the present invention compared with the prior art are:

[0039] (1) The method of the present invention embeds the designed on-chip column windowing algorithm into each image processing circuit, and the single-module circuit calculates independently. Without increasing costs, it can achieve flexible column windowing for the entire chip, reducing costs and power consumption.

[0040] (2) The present invention successively goes through the windowing position positioning, odd-even column start and end position correction processes, can obtain an accurate response of the current column control circuit to the column windowing instruction, and this response process is real-time. It does not require storing the data quantized by the readout circuit AD and then adjusting and outputting, saving resources and facilitating the realization of high-speed data transmission for non-storage image sensors. Brief Description of the Drawings

[0041] Figure 1 Schematic diagram of the execution process of the column windowing algorithm in the embodiment of the present invention

[0042] Figure 2 Column windowing start position correction algorithm in the embodiment of the present invention

[0043] Figure 3 Column windowing end position correction algorithm in the embodiment of the present invention

[0044] Figure 4 Schematic diagram of the start position and end position judgment in the embodiment of the present invention

[0045] Figure 5 Schematic diagram of the image sensor architecture according to an embodiment of the present invention Detailed implementation manners

[0046] The present invention will be further described below with reference to the accompanying drawings.

[0047] The column control circuit in the image sensor is divided into an odd-column control circuit and an even-column control circuit. The image sensor with a plain pixel array reads images bidirectionally through the odd-column control circuit and the even-column control circuit. The odd-column control circuit controls the downward output of data of columns 0, 2, …, M - 2 in the pixel array, and the even-column control circuit controls the upward output of data of columns 1, 3, …, M - 1 in the pixel array, where M is the total number of columns of all column data processed by the image sensor. When designing the chip, there are a total of 2E column control circuits in the image sensor, and the number of odd-column and even-column control circuits is the same, both being E, and E satisfies the following relationship:

[0048]

[0049] In the above formula, m is the number of pixel columns that a column control circuit needs to control, and the specific value is determined according to the rate of the high-speed serial port and the main frequency of the circuit during chip design:

[0050]

[0051] In the above formula, k is related to the number of column pixels controlled by the column control circuit, and the maximum number of column pixels controlled by a column control circuit is 2 k . k corresponds to the number of bits of the column selection information inside the column control circuit in Start_Column and End_Column.

[0052] Define the column window start position register Start_Column to store the starting column pixel position information corresponding to the output image; define the column window end position register End_Column to store the ending column pixel position information corresponding to the output image; the bit width D of Start_Column and End_Column is:

[0053]

[0054] The labels of the odd-column control circuit and the even-column control circuit start from 0 and end at E - 1. The total number of columns that the odd-column and even-column control circuits with the same label need to control is 2m. The quantity relationships among the column control circuit label, the column numbers controlled by the column control circuit with the corresponding label, and all pixel column numbers are shown in the following table:

[0055]

[0056] The internal column numbers of each odd-column control circuit and even-column control circuit are the same, both being 0, 1, 2,..., m - 1, and the column control circuit has a positioning function to distinguish the location of the data in each column.

[0057] Divide the bits of Start_Column and End_Column into three parts: parity flag, internal column selection bit of the column control circuit, and position label of the column control circuit:

[0058] a. Start_Column[0] and End_Column[0] are parity flag bits. 0 indicates the odd-column control circuit, and the data is output downward; 1 indicates the even-column control circuit, and the data is output upward.

[0059] b. Start_Column[k:1] and End_Column[k:1] are the internal column selection bits of the column control circuit, representing the column number of the current column inside the column circuit, with a range of (0)2 to (2 k -1)2;

[0060] c. Start_Column[D - 1:k + 1] and End_Column[D - 1:k + 1] are the position labels of the column control circuit where the current column is located. The number of column control circuits that Column[D - 1:k + 1] can represent satisfies:

[0061]

[0062] As Figure 1 shown, the method for on-chip column windowing of a large-area array bidirectional readout image sensor according to the present invention is as follows:

[0063] Step 1: Receive the windowing range of the column windowing operation input externally, including the start column number and the end column number. Convert the start column number and the end column number into corresponding D-bit binary numbers respectively. Write the D-bit binary number of the start column number into bits D-1 to 0 of Start_Column from the high bit to the low bit, and write the D-bit binary number of the end column number into bits D-1 to 0 of End_Column from the high bit to the low bit. Define the data in the latest Start_Column and End_Column as the current column windowing instruction. Specifically: The host computer inputs the start column number and the end column number of the windowing to the image sensor through the serial port according to the serial port protocol. The start column number and the end column number are mapped into Start_Column and End_Column in the form of binary values. Among them, Start_Column[0] indicates whether the start column number is on the odd column control circuit or the even column control circuit. Start_Column[k:1] represents the start output column number, and Start_Column[D-1:k+1] represents the number of the column control circuit where the start output column number is located. End_Column[0] indicates whether the end column number is on the odd column control circuit or the even column control circuit. End_Column[k:1] represents the end output column number, and End_Column[D-1:k+1] represents the number of the column control circuit where the end output column number is located.

[0064] For example: The image sensor has 128 columns of pixels, 16 column control circuits, and each column control circuit controls 8 columns of pixel data. The corresponding variable relationships in this algorithm are:

[0065] M = 2×8×8 = 128, E = 8, m = 8. At this time: k = log28 = 3, D = ceil(log2128) = 7.

[0066] If the externally input start column number is 35 and the end column number is 86, and the pixel column numbers are encoded starting from 0, and the column control circuits are numbered starting from 0:

[0067] (35)2 = 0100011, (86)2 = 1010110. At this time: The data in Start_Column from the high bit to the low bit is: 0100011,

[0068] Start_Column[0] = 1, Start_Column[k:1] = 001,

[0069] Start_Column[D-1:k+1] = 010; It shows that the data of the 35th column is located in the first column of the second even column control circuit, and the column data starts to be output from here.

[0070] The data in End_Column from high to low is: 1010110,

[0071] End_Column[0] = 0, End_Column[k:1] = 011,

[0072] End_Column[D - 1:k + 1] = 101; It indicates that the data in the 86th column is located in the 3rd column of the 5th odd-column control circuit, and the column data output ends here.

[0073] Step 2: Compare the position label information in the current column windowing instruction with the position label information in the current column control circuit position register to determine whether the column windowing instruction is valid for the current column control circuit. If the column windowing instruction is valid for the current column control circuit, go to Step 3. If the column windowing instruction is invalid for the current column control circuit, there is no output from the current column control circuit.

[0074] The specific method for determining whether the column windowing instruction is valid for the current column control circuit is: Extract Start_Column[D - 1:k + 1] and End_Column[D - 1:k + 1],

[0075] If Start_Column[D - 1:k + 1] is greater than the position label of the current column control circuit, it indicates that the column windowing instruction is invalid for the current column control circuit;

[0076] If End_Column[D - 1:k + 1] is less than the position label of the current column control circuit, it indicates that the column windowing instruction is invalid for the current column control circuit;

[0077] If Start_Column[D - 1:k + 1] is not greater than the position label of the current column control circuit and End_Column[D - 1:k + 1] is not less than the position label of the current column control circuit, then the column windowing instruction is valid for the current column control circuit.

[0078] For example: Start_Column[D - 1:k + 1] = 010, End_Column[D - 1:k + 1] = 101, then the windowing instruction is only valid for the odd-column control circuits and even-column control circuits with column control circuit numbers 2, 3, 4, and 5.

[0079] Step 3: Compare the size relationship between the position label information in Start_Column and End_Column and the position label in the current column control circuit position register respectively to determine the start column number and end column number for which the current column control circuit participates in windowing;

[0080] If Start_Column[D - 1:k + 1] is equal to the current column control circuit position, and End_Column[D - 1:k + 1] is equal to the current column control circuit position, perform odd / even column start position correction and odd / even column end position correction on the start column number and end column number of the current column control circuit participating in windowing in sequence;

[0081] If Start_Column[D - 1:k + 1] is equal to the current column control circuit position, and End_Column[D - 1:k + 1] is greater than the current column control circuit position, the end column number of the current column control circuit participating in windowing is the 2 k - 1 column, and perform odd / even column start position correction on the start column number;

[0082] If Start_Column[D - 1:k + 1] is less than the current column control circuit position, and End_Column[D - 1:k + 1] is equal to the current column control circuit position, the start column number of the current circuit participating in windowing is column 0, and perform odd / even column end position correction on the end column number;

[0083] If Start_Column[D - 1:k + 1] is less than the current column control circuit position, and End_Column[D - 1:k + 1] is greater than the current column control circuit position, the start column number of the current circuit participating in windowing is column 0, and the end column number is the 2 k - 1 column.

[0084] For example: Start_Column[D - 1:k + 1] = 010, End_Column[D - 1:k + 1] = 101. For the odd / even column control circuits numbered 3 and the odd / even column control circuits numbered 4, all column data are output. For the odd / even column control circuits numbered 2, the start column number needs to be corrected for the odd / even column start position, and the end column number is the 2 k - 1 column; for the odd / even column control circuits numbered 5, the start column number is 0, and the end column number needs to be corrected for the odd / even column end position.

[0085] Step 4: Perform odd / even column start position correction: Extract the odd / even identification bit in Start_Column, compare it with the odd / even information in the current column control circuit position register, and determine the actual start position of the current column control circuit.

[0086] The specific method is as Figure 2 shown:

[0087] If Start_Column[0] is 0 and the odd / even identification bit in the current column control circuit position register is 0, then the column numbers in Start_Column[k:1] are the start column numbers of the current column control circuit;

[0088] If Start_Column[0] is 0 and the parity flag bit in the current column control circuit position register is 1, then the starting column number of the current column control circuit is the column number in Start_Column[k:1].

[0089] If Start_Column[0] is 1 and the parity flag bit in the current column control circuit position register is 1, then the column number in Start_Column[k:1] is the starting column number of the current column control circuit.

[0090] If Start_Column[0] is 1 and the parity flag bit in the current column control circuit position register is 0, then the starting column number of the current column control circuit is the column number represented by Start_Column[k:1] + 1.

[0091] For example: Start_Column[0] = 1, Start_Column[k:1] = 001, Start_Column[D - 1:k + 1] = 010; draw the internal column number distribution diagram of the even column control circuit numbered 2, as Figure 4 shown in the lower left table. The first column of the even column control circuit numbered 2 stores the data of the 35th column of the entire pixel array. Correspondingly: the first column of the odd column control circuit numbered 2 stores the data of the 34th column of the entire pixel array, and the second column stores the data of the 36th column of the entire pixel array.

[0092] If the parity flag bit in the current column control circuit position register is 1, it indicates that the current is an even column control circuit, and the starting column number is the first column, that is, the column number represented by Start_Column[k:1].

[0093] If the parity flag bit in the current column control circuit position register is 0, it indicates that the current is an odd column control circuit, and the starting column number should be the second column, starting from the data of the 36th column of the pixel array, that is, the column number represented by Start_Column[k:1] + 1.

[0094] Step 5: Perform parity column end position correction: Extract the parity flag bit in End_Column and compare it with the parity information in the current column control circuit position register to determine the actual end position of the current column control circuit.

[0095] As Figure 3 shown: The implementation method of parity column end position correction is to compare End_Column[0] with the parity flag bit in the current column control circuit position register:

[0096] If End_Column[0] is 0 and the parity flag bit in the current column control circuit position register is 0, then the column number in End_Column[k:1] is the stop column number of the current column control circuit;

[0097] If End_Column[0] is 0 and the parity flag bit in the current column control circuit position register is 1, then the stop column number of the current column control circuit is the column number represented by End_Column[k:1] - 1;

[0098] If End_Column[0] is 1 and the parity flag bit in the current column control circuit position register is 1, then the column number in End_Column[k:1] is the stop column number of the current column control circuit;

[0099] If End_Column[0] is 1 and the parity flag bit in the current column control circuit position register is 0, then the stop column number of the current column control circuit is the column number in End_Column[k:1].

[0100] For example: End_Column[0] = 0, End_Column[k:1] = 011, End_Column[D - 1:k + 1] = 101;

[0101] Draw the internal column number distribution diagram of the odd column control circuit numbered 5, as Figure 4 shown in the lower right table. The 3rd column of the odd column control circuit numbered 5 stores the data of the 86th column of the entire pixel array. Correspondingly: the 2nd column of the even column control circuit numbered 5 stores the data of the 85th column of the entire pixel array, and the 3rd column stores the data of the 87th column of the entire pixel array.

[0102] If the parity flag bit in the current column control circuit position register is 0, it means that the current is an odd column control circuit, and the stop column number is the 3rd column, that is, the column number represented by End_Column[k:1].

[0103] If the parity flag bit in the current column control circuit position register is 1, it means that the current is an even column control circuit, and the stop column number should be the 2nd column, and the output of the data of the 85th column of the pixel array stops, that is, the column number represented by End_Column[k:1] - 1.

[0104] Such as Figure 5As shown in the figure, the internal circuit of the large area array image sensor applicable to the method of the present invention includes a pixel array, a readout circuit, a row timing control circuit, a column timing control circuit, a high-speed data interface, an instruction controller, etc. The odd and even column pixel data are output bidirectionally up and down respectively. Among them, the pixel array serves as the photosensitive circuit of the device, converting the optical signal into an electrical signal; the row timing control circuit mainly generates the timing signals of the internal switches of the pixel circuit; the readout circuit is used to collect the analog signals output by the pixels, convert them into digital signals through an analog-to-digital conversion circuit and send them through a high-speed serial interface; the column timing control circuit mainly operates on the digital signals output by the analog-to-digital converter, and embeds a variety of data processing algorithms. The column windowing algorithm described in the method of the present invention is in this level of circuit.

[0105] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. An on-chip column windowing data extraction method for a bidirectional readout image sensor, applicable to an image sensor in which a pixel array is read out bidirectionally through an odd-column control circuit and an even-column control circuit. The odd-column control circuit controls the downward output of data in the 0th column, 2nd column, …, (M - 2)th column of the pixel array, and the even-column control circuit controls the upward output of data in the 1st column, 3rd column, …, (M - 1)th column of the pixel array, where M is the total number of columns of all column data processed by the image sensor; in each column control circuit, there is an inherent column control circuit position register, which contains the parity information and position label information of the control circuit itself; it is characterized in that, It includes the following steps: Step 1: Define the D-column window start position register Start_Column and the D-column window end position register End_Column. Start_Column and End_Column are divided into three parts: parity flag, internal column selection information of the column control circuit, and position label information of the column control circuit. Among them: The position label information of the column control circuit in Start_Column stores the number of the column control circuit where output starts, and the internal column selection information in Start_Column stores the starting column number in the column control circuit where output starts; The position label information of the column control circuit in End_Column stores the number of the column control circuit where output ends, and the internal column selection information in End_Column stores the stopping column number in the column control circuit where output ends; Step 2: Receive the windowing range of the external input column windowing operation, including the starting column number and the ending column number. Write the starting column number into Start_Column after radix conversion to obtain the starting column windowing instruction, and write the ending column number into End_Column after radix conversion to obtain the ending column windowing instruction; For each column control circuit, perform the operations in Steps 3 to 6: Step 3: If the position label of the column control circuit itself is less than the position label of the column control circuit in the starting column windowing instruction, it means the starting column windowing instruction is invalid for the current column control circuit, and there is no output from the current column control circuit; If the position label of the current column control circuit is greater than the position label of the column control circuit in the ending column windowing instruction, it means the ending column windowing instruction is invalid for the current column control circuit, and there is no output from the current column control circuit; If the position label of the current column control circuit is between the position labels of the column control circuits in the starting column windowing instruction and the ending column windowing instruction, go to Step 4; If the position label of the current column control circuit is equal to the position label of the column control circuit in the starting column windowing instruction, go to Step 5; If the position label of the current column control circuit is equal to the position label of the column control circuit in the ending column windowing instruction, go to Step 6; Step 4. Determine the starting column number and ending column number of the current column control circuit for window opening: The starting column number of the current column control circuit is column 0, and the stopping column number is column 2 k - 1; Where: k corresponds to the number of bits of the internal column selection information of the column control circuit in Start_Column and End_Column; Step 5: Determine that the current column control circuit is the column control circuit where the starting column number in the windowing range is located, and its starting column number; Step 6: Determine that the current column control circuit is the column control circuit where the ending column number in the windowing range is located, and its stopping column number; Step 7: Extract the column pixel data corresponding to the windowing range of the external input according to the starting column number and the stopping column number of the column control circuit participating in windowing determined in Steps 3 to 6; Among them, the method for determining the column control circuit where the starting column number in Step 5 is located and its starting column number is as follows: Compare the [0] bit of the starting column windowing instruction with the parity flag bit in the position register of the current column control circuit: If the parity flag bit in the position register of the current column control circuit is the same as the [0] bit of the starting column windowing instruction, then the current column control circuit is the column control circuit where the starting column number is located, and the starting column number is the [k:1] bit of the starting column windowing instruction; If the parity flag bit in the current column control circuit position register is different from the [0] bit of the start column windowing instruction, then the current column control circuit is not the column control circuit where the start column number is located. The determination method of the start column number is as follows: If the parity flag bit in the current column control circuit position register is 1 and the [0] bit of the start column windowing instruction is 0, then the start column number of the current column control circuit is the [k:1] bits of the start column windowing instruction; If the parity flag bit in the current column control circuit position register is 0 and the [0] bit of the start column windowing instruction is 1, then the start column number of the current column control circuit is the [k:1] bits of the start column windowing instruction + 1; The determination method of the column control circuit where the end column number is located in step 6 and its stop column number is as follows: Compare the [0] bit of the end column windowing instruction with the parity flag bit in the current column control circuit position register: If the parity flag bit in the current column control circuit position register is the same as the [0] bit of the end column windowing instruction, then the current column control circuit is the column control circuit where the end column number is located, and the stop column number is the [k:1] bits of the end column windowing instruction; If the parity flag bit in the current column control circuit position register is different from the [0] bit of the end column windowing instruction, then the current column control circuit is not the column control circuit where the end column number is located. The determination method of the stop column number is as follows: If the parity flag bit in the current column control circuit position register is 1 and the [0] bit of the end column windowing instruction is 0, then the stop column number of the current column control circuit is the [k:1] bits of the end column windowing instruction - 1; If the parity flag bit in the current column control circuit position register is 0 and the [0] bit of the end column windowing instruction is 1, then the stop column number of the current column control circuit is the [k:1] bits of the end column windowing instruction.

2. The method for on-chip column window data extraction of a bidirectional readout image sensor according to claim 1, wherein There are a total of 2E column control circuits in the image sensor. The labels of the odd-column control circuits and the even-column control circuits both start from 0 and end at E-1. The number of column data columns m controlled by each column control circuit is 2 k , and the internal column numbers of each column control circuit are all 0, 1, …, 2 k -1. The total number of pixel columns that need to be controlled by the odd-column control circuits and the even-column control circuits with the same label is 2m. The total number of columns M of all column pixels that the image sensor can process is 2Em, and the column numbers are 0, 1, …, 2Em-1.

3. The on-chip column window data extraction method for a bidirectional readout image sensor according to claim 2, characterized in that, The data division method of the said Start_Column and End_Column is as follows: a. Start_Column[0] and End_Column[0] are parity flag bits. 0 indicates an odd column control circuit, and the data is output downward; 1 indicates an even column control circuit, and the data is output upward; b. Start_Column[k:1] represents the column number of the start column inside the column control circuit, and End_Column[k:1] represents the column number of the end column inside the column control circuit. The range that Start_Column[k:1] and End_Column[k:1] can represent is (0)2 to (2 k -1)2; c. Start_Column[D - 1:k + 1] represents the number of the column control circuit where the start column is located, End_Column[D - 1:k + 1] is the number of the column control circuit where the end column is located. The number of column control circuits that Start_Column[D - 1:k + 1] and End_Column[D - 1:k + 1] can represent satisfies:

4. The on-chip column window data extraction method for a bidirectional readout image sensor according to claim 1, characterized in that, The bit width D of the column windowing start position register Start_Column and the column windowing end position register End_Column is:

5. A method for extracting on-chip column window data of a bidirectional readout image sensor according to claim 3, characterized in that, In step 2, the start column number and the end column number are respectively converted into corresponding D-bit binary numbers. When the number of bits is less than D, 0 is filled in the high bits. The D-bit binary number of the start column number is written into the D - 1 to 0 bits of Start_Column from high to low to obtain the start column windowing instruction, and the D-bit binary number of the end column number is written into the D - 1 to 0 bits of End_Column from high to low to obtain the end column windowing instruction.

6. A method for extracting on-chip column window data of a bidirectional readout image sensor according to claim 5, characterized in that, The [D-1:k+1] bits of the start column windowing instruction represent the number of the column control circuit where the start column number is located. The [k:1] bits of the start column windowing instruction represent the column number in the column control circuit where the start column number is located. The [0] bit of the start column windowing instruction represents whether the column control circuit where the start column number is located is an odd column control circuit or an even column control circuit. The [D-1:k+1] bits of the end column windowing instruction represent the number of the column control circuit where the end column number is located. The [k:1] bits of the end column windowing instruction represent the column number in the column control circuit where the end column number is located. The [0] bit of the end column windowing instruction represents whether the column control circuit where the end column number is located is an odd column control circuit or an even column control circuit.

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