Image zooming method with arbitrary magnification

Abstract

A method for image scaling with arbitrary magnification includes: (A) calculating a horizontal resolution difference and a vertical resolution difference; (B) calculating a horizontal division substitution value and a vertical division substitution value; (C) generating a column index value and a horizontal difference value of a lower right pixel of a corresponding original image based on the horizontal resolution difference for the column index value of the pixel of the target image; (D) generating a row index value and a vertical difference value of a lower right pixel of the corresponding original image based on the vertical resolution difference for the row index value of the pixel of the target image, thereby obtaining that the pixel of the target image corresponding to the original image is located between an upper left pixel, an upper right pixel, a lower left pixel, and the lower right pixel of the original image; and (E) using interpolation and right shift operations to bilinearly interpolate the pixel values of four pixels of the original image based on the horizontal division substitution value, the vertical division substitution value, the horizontal difference, and the vertical difference, thereby obtaining the pixel value of the pixel of the target image.

Description

Technical Field

[0001] The present invention relates to the technical field of image zooming, and in particular to a method for zooming an image with an arbitrary magnification achieved by a display driving circuit. Background Art

[0002] Today's digital displays, such as LCDs, OLEDs, and Micro LEDs, all have fixed panel resolutions. Therefore, if the resolution of the input video signal doesn't match the panel resolution, the image won't display correctly. Therefore, display driver chips require image scaling circuits to support various resolutions.

[0003] The most commonly used algorithm for image scaling is the bilinear interpolation algorithm (Bilinear Interpolation), such as Figure 1 As shown, by using a bilinear interpolation algorithm, for example, an original image with a resolution of W×H can be scaled to a target image with a resolution of NW×NH. The operation is mainly used to calculate whether the target pixel T(i, j) in the target image is located between the four pixels of the original image, namely the upper left pixel P(x-1, y-1), the upper right pixel P(x, y-1), the lower left pixel P(x-1, y), and the lower right pixel P(x, y) of the original image. Based on this position information, the pixel values of these four pixels P(x-1, y-1), P(x, y-1), P(x-1, y), and P(x, y) are bilinearly interpolated to calculate the pixel value of the target pixel T(i, j). In this way, the pixel values of all pixels of the target image can be obtained, and image scaling is completed.

[0004] However, in the aforementioned bilinear interpolation algorithm, four division operations must be used in the bilinear interpolation calculation for each pixel of the target image to obtain the interpolation weight for each pixel. Since division operations are complex operations that require a large area and consume a lot of power for integrated circuit hardware, to avoid the use of division operations in integrated circuit hardware, current integrated circuit hardware designs use a cyclic relationship of coefficients with specific magnifications to establish a lookup table (LUT) to obtain the interpolation weight for each pixel.

[0005] Because existing technologies require the use of lookup tables established for different image scaling factors to search for weights and perform interpolation for different image signal resolutions, typical driver circuits can only support specific scaling factors, such as 4 / 3x scaling, 1.5x scaling, and 2x scaling, and cannot support arbitrary image signal resolutions. This makes it difficult to meet practical needs and necessitates improvement. Summary of the Invention

[0006] The main purpose of the present invention is to provide an arbitrary magnification image scaling method that does not require the use of a lookup table and can use low-complexity calculations to enable a display driver circuit to support arbitrary magnification scaling based on bilinear interpolation to correspond to arbitrary image signal resolution.

[0007] To achieve the aforementioned objectives, the present invention provides an arbitrary magnification image scaling method for scaling an original image into a target image, wherein the original image and the target image each include a plurality of pixels arranged in rows and columns and each have a horizontal resolution and a vertical resolution. The method comprises the steps of: (A) calculating a horizontal resolution difference value as the horizontal resolution of the original image minus the horizontal resolution of the target image, and calculating a vertical resolution difference value as the vertical resolution of the original image minus the vertical resolution of the target image; and (B) calculating a horizontal division substitution value as the value obtained by rounding off a preset value that is a power of 2 divided by the horizontal resolution of the target image, and calculating a vertical division substitution value as the value obtained by rounding off a preset value that is a power of 2 divided by the vertical resolution of the target image. (C) for the column index value of the pixel of the target image, generating a column index value of a lower right pixel of the corresponding original image and a horizontal difference value according to the horizontal resolution difference value; (D) for the row index value of the pixel of the target image, generating a row index value of the lower right pixel of the corresponding original image and a vertical difference value according to the vertical resolution difference value, thereby obtaining that the pixel of the target image corresponding to the original image is located between four pixels, namely, an upper left pixel, an upper right pixel, a lower left pixel, and the lower right pixel of the original image; and (E) according to the horizontal division substitution value, the vertical division substitution value, the horizontal difference value and the vertical difference, using interpolation and right shift operations to perform bilinear interpolation on the pixel values of the four pixels of the original image, thereby obtaining the pixel value of the pixel of the target image. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 FIG. 1 is a schematic diagram of a conventional technique for implementing a bilinear interpolation algorithm using a lookup table for image scaling.

[0009] Figure 2 FIG. 1 is a schematic diagram of an image zooming method with arbitrary magnification implemented by a display driving circuit according to the present invention.

[0010] Figure 3 The flowchart is a calculation flow of the column index values and horizontal difference values of the pixels of the original image when the target image is magnified in horizontal resolution relative to the original image.

[0011] Figure 4 The flowchart is a flowchart for calculating the column index values and horizontal difference values of the pixels of the original image when the horizontal resolution of the target image is reduced relative to the original image.

[0012] Figure 5 The flowchart is a calculation flow of the row index value and the vertical difference value of the pixel of the original image when the target image is magnified in vertical resolution relative to the original image.

[0013] Figure 6 The flowchart is a calculation flow of the row index value and the vertical difference value of the pixel of the original image when the vertical resolution of the target image is reduced relative to the original image. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the implementation of the present invention and are not intended to limit the present invention.

[0015] Figure 2 The image scaling method of the present invention implemented by a display driving circuit at an arbitrary magnification is to scale an original image 10 into a target image 20, wherein the original image 10 and the target image 20 each include a plurality of pixels arranged in rows and columns. The horizontal resolution of the original image 10 is represented by O_X_res, the vertical resolution of the original image 10 is represented by O_Y_res, and the pixels of the original image 10 are represented by P(x, y), where x is the column index value of the original image 10 and ranges from 0 to O_X_res-1, and y is the row index value of the original image 10 and ranges from 0 to O_Y_res-1. The horizontal resolution of the target image 20 is represented by T_X_res, the vertical resolution of the target image 20 is represented by T_Y_res, and the pixels of the target image 20 are represented by T(i, j), where i is the column index value of the target image 20 and ranges from 0 to T_X_res-1, and j is the row index value of the target image 20 and ranges from 0 to T_Y_res-1.

[0016] Figure 2The flowchart of the image scaling method with arbitrary magnification implemented by the display driving circuit of the present invention is also shown. First, in step S31, a horizontal resolution difference Delta_X is calculated as the horizontal resolution of the original image 10 minus the horizontal resolution of the target image 20 (i.e., Delta_X = O_X_res - T_X_res), and a vertical resolution difference Delta_Y is calculated as the vertical resolution of the original image 10 minus the vertical resolution of the target image 20 (i.e., Delta_Y = O_Y_res - T_Y_res). Next, in step S32, a horizontal division substitution value i_Target_X is calculated as a value obtained by dividing a preset value of a power of 2 by the horizontal resolution T_X_res of the target image 20 and rounding it off, that is, i_Target_X=Roundoff(2n / T_X_res), where n is an integer greater than 1, for example, n=15, and a vertical division substitution value i_Target_Y is calculated as a value obtained by dividing a preset value of a power of 2 by the vertical resolution T_Y_res of the target image 20 and rounding it off, that is, i_Target_Y=Roundoff(2m / T_Y_res), where m is an integer greater than 1, for example, m=16. Since this step includes a division operation, in the present invention, Figure 2 As shown, steps S31 and S32 are performed outside the display driving circuit 30 , for example, implemented in software, firmware or other manners, and serve as inputs to the display driving circuit 30 for performing bilinear interpolation calculations.

[0017] Next, steps S33-S35 performed within the display driving circuit 30 calculate, for each pixel T(i,j) of the target image 20, the position of the pixel T(i,j) corresponding to the original image 10, which is located between the four pixels of the original image 10, namely, the upper left pixel P(x-1,y-1), the upper right pixel P(x,y-1), the lower left pixel P(x-1,y), and the lower right pixel P(x,y), so as to perform bilinear interpolation using the pixel values of the pixels P(x-1,y-1), P(x,y-1), P(x-1,y), and P(x,y) to obtain the pixel value of the pixel T(i,j).

[0018] In step S33, for the pixel T(i,j) of the target image 20, the row index value i=0 to T_X_res-1, the row index value x and the horizontal difference value dx of the lower right pixel P(x,y) of the corresponding original image 10 are generated according to the horizontal resolution difference value Delta_X. Further, for the row index value i, if the target image 20 is magnified in horizontal resolution relative to the original image 10, please refer to Figure 3The calculation process can be used to calculate the row index value x and the horizontal difference value dx as follows: when the row index value i is equal to 0, the row index value x is 1 and the horizontal difference value dx is half of the horizontal resolution difference value Delta_X (i.e., x=1 and dx=Delta_X / 2); when the row index value i is greater than or equal to 1, each time the row index value i increases by 1, the row index value x increases by 1 and the horizontal difference value dx increases by the horizontal resolution difference value Delta_X (i.e., x=x+1 and dx=dx+Delta_X); when the horizontal difference value dx is less than the horizontal resolution value T_X_res, the row index value x is increased by 1 and the horizontal difference value dx is added to the horizontal resolution value T_X_res of the target image 20 (i.e., x=x+1 and dx=dx+T_X_res).

[0019] Similarly, for the column index value i, if the target image 20 is reduced in horizontal resolution relative to the original image 10, please refer to Figure 4 The calculation process can be used to calculate the row index value x and the horizontal difference value dx as follows: when the row index value i is equal to 0, the row index value x is 1 and the horizontal difference value dx is half of the horizontal resolution difference value Delta_X (that is, x=1 and dx=Delta_X / 2); when the row index value i is greater than or equal to 1, then each time the row index value i increases by 1, the row index value x increases by 1 and the horizontal difference value dx increases by the horizontal resolution difference value Delta_X (that is, x=x+1 and dx=dx+Delta_X); when the horizontal difference value dx is greater than or equal to the horizontal resolution value T_X_res, the row index value x is increased by 1 and the horizontal resolution value T_X_res of the target image 20 is subtracted from the horizontal difference value dx (that is, x=x+1 and dx=dx–T_X_res).

[0020] In step S34, the row index value j=0 to T_Y_res-1 of the pixel T(i,j) of the target image 20 is used to generate the row index value y and the vertical difference value dy of the lower right pixel P(x,y) of the corresponding original image 10 according to the vertical resolution difference value Delta_Y. Further, for the row index value j, if the target image 20 is magnified in vertical resolution relative to the original image 10, please refer to Figure 5The calculation process can be used to calculate the row index value y and the vertical difference dy as follows: when the row index value j is equal to 0, the row index value y is 1 and the vertical difference dy is half of the vertical resolution difference Delta_Y (that is, y=1 and dy=Delta_Y / 2); when the row index value j is greater than or equal to 1, then every time the row index value j increases by 1, the row index value y increases by 1 and the vertical difference dy increases by the vertical resolution difference Delta_Y (that is, y=y+1 and dy=dy+Delta_Y); when the vertical difference dy is less than the vertical resolution T_Y_res, the row index value y is increased by 1 and the vertical difference dy is added to the vertical resolution T_Y_res of the target image 20 (that is, y=y+1 and dy=dy+T_Y_res).

[0021] Similarly, for row index value j, if the target image 20 is reduced in vertical resolution relative to the original image 20, please refer to Figure 6 The calculation process can calculate the row index value y and the vertical difference dy as follows: when the row index value j is equal to 0, the row index value y is 1 and the vertical difference dy is half of the vertical resolution difference Delta_Y (that is, y=1 and dy=Delta_Y / 2); when the row index value j is greater than or equal to 1, then every time the row index value j increases by 1, the row index value y increases by 1 and the vertical difference dy increases by the vertical resolution difference Delta_Y (that is, y=y+1 and dy=dy+Delta_Y); when the vertical difference dy is greater than or equal to the vertical resolution T_Y_res, the row index value y is increased by 1 and the vertical resolution T_Y_res of the target image 20 is subtracted from the vertical difference dy (that is, y=y+1 and dy=dy–T_Y_res).

[0022] Based on the lower right pixel P(x, y) obtained in steps S33 and S34 above, the position information of pixel T(i, j) of the target image 20 corresponding to the original image 10 can be obtained, which is located between the upper left pixel P(x-1, y-1), the upper right pixel P(x, y-1), the lower left pixel P(x-1, y), and the lower right pixel P(x, y) of the original image 10. In an image display, a pixel includes at least one specific color sub-pixel and has at least one specific color pixel value. For example, a pixel may include a red sub-pixel, a green sub-pixel, and a blue sub-pixel and have a red pixel value, a green pixel value, and a blue pixel value. For simplicity, the present invention is described as a pixel including a specific color sub-pixel and having a specific color pixel value, but the present invention is not limited to this. It is conceivable that the specific color pixel value may include a red pixel value, a green pixel value, a blue pixel value, or a combination of other color pixel values. Accordingly, the specific color pixel values of the pixels P(x-1,y-1), P(x,y-1), P(x-1,y), P(x,y) of the original image 10 are s_P(x-1,y-1), s_P(x,y-1), s_P(x-1,y), s_P(x,y), and the specific color pixel value of the pixel T(i,j) of the target image 20 is s_T(i,j).

[0023] Step S35 performs bilinear interpolation on the pixel values s_P(x-1, y-1), s_P(x, y-1), s_P(x-1, y), and s_P(x, y) of the four pixels of the original image 10 using interpolation and right shift operations using the horizontal division substitution value i_Target_X, the vertical division substitution value i_Target_Y, the horizontal difference dx, and the vertical difference dy to obtain the pixel value s_T(i, j) of the target image 10. Since bilinear interpolation includes interpolation operations in two directions, namely horizontal interpolation and vertical interpolation, step S35 can first perform the horizontal interpolation operation and then the vertical interpolation operation, or first perform the vertical interpolation operation and then the horizontal interpolation operation.

[0024] When step S35 first performs horizontal interpolation and then vertical interpolation, in the horizontal interpolation operation, a first horizontal interpolation value xA for the pixel T(i,j) of the target image 20 corresponding to the pixels P(x-1,y-1) and P(x,y-1) of the original image 10 is calculated by interpolation and right shifting by n bits based on the pixel values s_P(x-1,y-1) and s_P(x,y-1) of the original image 10, the horizontal difference value dx, and the horizontal division substitution value i_Target_X. A second horizontal interpolation value xB for the pixel T(i,j) of the target image 20 corresponding to the pixels P(x-1,y) and P(x,y) of the original image 10 is calculated by interpolation and right shifting by n bits based on the pixel values s_P(x-1,y) and s_P(x,y) of the original image 10, the horizontal difference value dx, and the horizontal division substitution value i_Target_X. More specifically, xA=(s_P(x-1,y-1)+(s_P(x,y-1)-s_P(x-1,y-1))·dx·i_Target_X)>>n, xB=(s_P(x-1,y)+(s_P(x,y)-s_P(x-1,y))·dx·i_Target_X)>>n. In the vertical interpolation operation, the pixel value s_T(i,j) of the pixel T(i,j) of the target image 20 is calculated based on the first horizontal interpolation value xA, the second horizontal interpolation value xB, the vertical difference dy, and the vertical division substitution value i_Target_Y. Interpolation and right shifting by m bits are performed. More specifically, s_T(i,j) = (xA + (xB – xA) dy i_Target_Y) >> m. In this way, the pixel value of each pixel of the target image 20 can be calculated to complete image scaling.

[0025] When step S35 first performs vertical interpolation and then horizontal interpolation, in the vertical interpolation operation, a first vertical interpolation value yA for the pixel T(i,j) of the target image 20 corresponding to the pixels P(x-1,y-1) and P(x-1,y) of the original image 10 is calculated by interpolation and right shifting by m bits based on the pixel values s_P(x-1,y-1) and s_P(x-1,y) of the original image 10, and a second vertical interpolation value yB for the pixel T(i,j) of the target image 20 corresponding to the pixels P(x,y-1) and P(x,y) of the original image 10 is calculated by interpolation and right shifting by m bits based on the pixel values s_P(x,y-1) and s_P(x,y) of the original image 10, the vertical interpolation value dy and the vertical division substitution value i_Target_Y. More specifically, yA=(s_P(x-1,y-1)+(s_P(x-1,y)-s_P(x-1,y-1))·dy·i_Target_Y)>>m, yB=(s_P(x,y-1)+(s_P(x,y)-s_P(x,y-1))·dy·i_Target_Y)>>m. In the horizontal interpolation operation, the pixel value s_T(i,j) of the pixel T(i,j) of the target image 20 is calculated based on the first vertical interpolation value yA, the second vertical interpolation value yB, the horizontal difference value dx, and the horizontal division substitution value i_Target_X. Interpolation and right shifting by n bits are performed. More specifically, s_T(i,j) = (yA + (yB – yA) · dx · i_Target_X) >> n. In this way, the pixel value of each pixel in the target image 20 can be calculated to complete image scaling.

[0026] As can be seen from the above description, the image scaling method of the present invention can be implemented in a display driver circuit without requiring division operations or different lookup tables for different scaling factors. This method can achieve scaling functions of any magnification to support any image signal resolution. Furthermore, the image scaling method of the present invention simplifies calculations and reduces the complexity of image scaling in the display driver circuit.

[0027] The above embodiments are merely examples for the convenience of description. The scope of rights claimed by the present invention should be based on the claims, and is not limited to the above embodiments.

Claims

1. A method for scaling an image at an arbitrary magnification, for scaling an original image into a target image, wherein the original image and the target image each include a plurality of pixels arranged in rows and columns and each have a horizontal resolution and a vertical resolution, wherein: The method comprises the steps of: (A) calculating a horizontal resolution difference as the horizontal resolution of the original image minus the horizontal resolution of the target image, and calculating a vertical resolution difference as the vertical resolution of the original image minus the vertical resolution of the target image; (B) calculating a horizontal division substitution value by dividing a predetermined value that is a power of 2 by the horizontal resolution of the target image and rounding off the result, and calculating a vertical division substitution value by dividing a predetermined value that is a power of 2 by the vertical resolution of the target image and rounding off the result; (C) For the column index value of the pixel of the target image, the column index value of a lower right pixel of the corresponding original image and a horizontal difference value are generated according to the horizontal resolution difference value; wherein, when the target image is magnified in terms of horizontal resolution relative to the original image, the column index value of the pixel of the original image and the horizontal difference value are calculated according to the following steps: when the column index value of the pixel of the target image is equal to 0, the column index value of the pixel of the original image is 1 and the horizontal difference value is half of the horizontal resolution difference value; and when the column index value of the pixel of the target image is sequentially from 1 to the horizontal resolution of the target image minus 1, the following steps are performed: the column index value of the pixel of the original image is increased by 1 and the horizontal difference value is increased by the horizontal resolution difference value, and further it is determined that when the horizontal difference value is less than the horizontal resolution of the target image, the column index value of the pixel of the original image is increased by 1. The index value is increased by 1 and the horizontal difference value is added to the horizontal resolution of the target image; or wherein, when the target image is reduced in horizontal resolution relative to the original image, the row index value of the pixel of the original image and the horizontal difference value are calculated according to the following steps: when the row index value of the pixel of the target image is equal to 0, the row index value of the pixel of the original image is 1 and the horizontal difference value is half of the horizontal resolution difference value; and when the row index value of the pixel of the target image is sequentially from 1 to the horizontal resolution of the target image minus 1, the row index value of the pixel of the original image is increased by 1 and the horizontal difference value is increased by the horizontal resolution difference value, and further when it is determined that the horizontal difference value is greater than or equal to the horizontal resolution of the target image, the row index value of the pixel of the original image is increased by 1 and the horizontal difference value is subtracted from the horizontal resolution of the target image; (D) for the row index value of the pixel of the target image, the row index value of the lower right pixel of the corresponding original image and a vertical difference value are generated according to the vertical resolution difference value, thereby obtaining the position of the pixel of the target image corresponding to the original image, which is located between an upper left pixel, an upper right pixel, a lower left pixel, and the lower right pixel of the original image; wherein, when the target image is magnified in vertical resolution relative to the original image, the row index value of the pixel of the original image and the vertical difference value are calculated according to the following steps: when the row index value of the pixel of the target image is equal to 0, the row index value of the pixel of the original image is 1 and the vertical difference value is half of the vertical resolution difference value; and when the row index value of the pixel of the target image is sequentially 1 to the vertical resolution of the target image minus 1, the row index value of the pixel of the original image is increased by 1 and the vertical difference value is increased by the vertical resolution difference, and further determining when the vertical difference value is greater than 0. When the vertical resolution of the target image is smaller than that of the target image, the row index value of the pixel of the original image is increased by 1 and the vertical difference value is added to the vertical resolution of the target image; or when the target image is reduced in vertical resolution relative to the original image, the row index value of the pixel of the original image and the vertical difference value are calculated according to the following steps: when the row index value of the pixel of the target image is equal to 0, the row index value of the pixel of the original image is 1 and the vertical difference value is half of the vertical resolution difference value; and when the row index value of the pixel of the target image is sequentially from 1 to the vertical resolution of the target image minus 1, the row index value of the pixel of the original image is increased by 1 and the vertical difference value is increased by the vertical resolution difference value, and further when it is determined that the vertical difference value is greater than or equal to the vertical resolution of the target image, the row index value of the pixel of the original image is increased by 1 and the vertical difference value is subtracted from the vertical resolution of the target image; and (E) Bilinearly interpolating the pixel values of the four pixels of the original image using interpolation and right shifting operations based on the horizontal division substitution value, the vertical division substitution value, the horizontal difference value, and the vertical difference value to obtain the pixel values of the pixels of the target image.

2. The image zooming method of claim 1, wherein: In step (B), , where i_Target_X represents the horizontal division substitution value, Roundoff() is the rounding function, n is an integer greater than 1, and T_X_res represents the horizontal resolution of the target image; , where i_Target_Y represents the vertical division substitution value, Roundoff() is the rounding function, m is an integer greater than 1, and T_Y_res represents the vertical resolution of the target image.

3. The image zooming method with arbitrary magnification according to claim 2, wherein: In step (E), the bilinear interpolation includes a horizontal interpolation operation and a vertical interpolation operation, and the horizontal interpolation operation is performed first, and then the vertical interpolation operation is performed.

4. The image zooming method with arbitrary magnification according to claim 3, wherein: In the horizontal interpolation operation, a first horizontal interpolation value of the target image pixel corresponding to the upper left pixel and the upper right pixel of the original image is calculated based on the pixel values of the upper left pixel and the upper right pixel of the original image, the horizontal difference value, and the horizontal division substitution value by interpolation and right shifting by n bits. And a second horizontal interpolation value of the target image pixel corresponding to the lower left pixel and the lower right pixel of the original image is calculated based on the pixel values of the lower left pixel and the lower right pixel of the original image, the horizontal difference value, and the horizontal division substitution value by interpolation and right shifting by n bits.

5. The image zooming method with arbitrary magnification according to claim 4, wherein: ,and , where xA represents the first horizontal interpolation value, xB represents the second horizontal interpolation value, s_P(x-1,y-1) is the pixel value of the upper-left pixel of the original image, s_P(x,y-1) is the pixel value of the upper-right pixel of the original image, s_P(x-1,y) is the pixel value of the lower-left pixel of the original image, and s_P(x,y) is the pixel value of the lower-right pixel of the original image. dx represents the horizontal difference, i_Target_X represents the horizontal division substitution value, and >> represents a right shift operation.

6. The method for image zooming at any magnification as claimed in claim 4, wherein: In the vertical interpolation operation, pixel values of pixels of the target image are calculated based on the first horizontal interpolation value, the second horizontal interpolation value, the vertical difference value, and the vertical division substitution value by interpolation and right shifting by m bits.

7. The image zooming method of claim 6, wherein: , where s_T(i,j) represents the pixel value of the target image, xA represents the first horizontal interpolation value, xB represents the second horizontal interpolation value, dy represents the vertical difference value, i_Target_Y represents the vertical division substitution value, and >> is a right shift operation.

8. The method for image zooming at any magnification as claimed in claim 2, wherein: In step (E), the bilinear interpolation includes a horizontal interpolation operation and a vertical interpolation operation, and the vertical interpolation operation is performed first, and then the horizontal interpolation operation is performed.

9. The method for image zooming at any magnification as claimed in claim 8, wherein: In the vertical interpolation operation, a first vertical interpolation value of the target image pixel corresponding to the upper left pixel and lower left pixel of the original image is calculated based on the pixel values of the upper left pixel and lower left pixel of the original image, the vertical difference value, and the vertical division substitution value by interpolation and right shifting by m bits. A second vertical interpolation value of the target image pixel corresponding to the upper right pixel and lower right pixel of the original image is calculated based on the pixel values of the upper right pixel and lower right pixel of the original image, the vertical difference value, and the vertical division substitution value by interpolation and right shifting by m bits.

10. The image zooming method with arbitrary magnification according to claim 9, wherein: ,and , where yA represents the first vertical interpolated value, yB represents the second vertical interpolated value, s_P(x-1,y-1) is the pixel value of the upper-left pixel of the original image, s_P(x,y-1) is the pixel value of the upper-right pixel of the original image, s_P(x-1,y) is the pixel value of the lower-left pixel of the original image, s_P(x,y) is the pixel value of the lower-right pixel of the original image, dy represents the vertical difference, i_Target_Y represents the vertical division substitution value, and >> is a right shift operation.

11. The image zooming method of claim 9, wherein: In the horizontal interpolation operation, pixel values of pixels of the target image are calculated based on the first vertical interpolation value, the second vertical interpolation value, the horizontal difference value, and the horizontal division substitution value by interpolation and right shifting by n bits.

12. The method for image zooming with arbitrary magnification according to claim 11, wherein: , where s_T(i,j) represents the pixel value of the target image, yA represents the first vertical interpolation value, yB represents the second vertical interpolation value, dx represents the horizontal difference value, i_Target_X represents the horizontal division substitution value, and >> is a right shift operation.

13. The image zooming method of any magnification as claimed in claim 1, wherein: The steps (C) to (E) are performed inside a display driving circuit.

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