Mobile communication terminal equipped with camera having image distortion compensation function
View Patent ↗Disclosed herein is a mobile communication terminal equipped with a camera having an image distortion compensation function which compensates image distortion created by a luminance difference between pixels in the vicinity of a central portion of a pixel array of an image sensor and pixels in the vicinity of an outer portion of a pixel array of the image sensor by detecting a Y-component value of the central pixel of the pixel array of the image sensor and Y-component values of the pixels located diagonally to the central pixel, comparing the Y-component value of the central pixel with the Y-component values of the pixels located diagonally to the central pixel, generating compensation values for compensating signal distortion in each of the pixels located diagonally to the central pixel according to the comparison result, and outputting a distortion compensation command, together with the compensation values, to the ISP (image signal processor).
1. A mobile communication terminal equipped with a camera having an image distortion compensation function, comprising:
an image sensor for converting an imaging signal formed by light incident through a lens to Raw Bayer RGB format data;
an ISP (image signal processor) for converting the Raw Bayer RGB format data to RGB format data, which in turn is converted to YUV format data suitable for a display in the mobile communication terminal; and
a back-end chip for processing the YUV format data output from the ISP to display a photographed image on an LCD (liquid crystal display) of the mobile communication terminal,
wherein the back-end chip includes an image distortion compensation module comprising:
a detection unit for detecting a Y-component value of a central pixel of a pixel array of the image sensor and Y-component values of pixels located diagonally to the central pixel;
a comparison unit for comparing the Y-component value of the central pixel with the Y-component values of the pixels located diagonally to the central pixel;
a compensation value generation unit for generating compensation values for compensating Y-component signal distortion in each of the pixels located diagonally to the central pixel according to a comparison result from the comparison unit; and
a distortion compensation processing unit for outputting a distortion compensation command, together with the compensation values generated by the compensation value generation unit, to the ISP.
2. The mobile communication terminal of claim 1 , wherein the image distortion compensation module further comprises a compensation value storage unit for storing the compensation values generated by the compensation value generation unit.
3. The mobile communication terminal of claim 2 , wherein the comparison unit compares the Y-component value of the central pixel with Y-component values of pixels or a group of pixels selected from the pixels located diagonally to the central pixel.
4. The mobile communication terminal of claim 3 , wherein the compensation values generated by the compensation value generation unit further comprise values for compensating distortions in U-component and V-component signals of each of the pixels located diagonally to the central pixel.
5. The mobile communication terminal of claim 1 , wherein the ISP compensates image distortions in the pixels located diagonally to the central pixel of the pixel array of the image sensor according to the compensation command from the image distortion compensation module.
6. The mobile communication terminal of claim 2 , wherein the ISP compensates image distortions in the pixels located diagonally to the central pixel of the pixel array of the image sensor according to the compensation command from the image distortion compensation module.
7. The mobile communication terminal of claim 3 , wherein the ISP compensates image distortions in the pixels located diagonally to the central pixel of the pixel array of the image sensor according to the compensation command from the image distortion compensation module.
8. The mobile communication terminal of claim 4 , wherein the ISP compensates image distortions in the pixels located diagonally to the central pixel of the pixel array of the image sensor according to the compensation command from the image distortion compensation module.
9. The mobile communication terminal of claim 5 , wherein a communication between the distortion compensation processing unit and the ISP is conducted via an IIC (inter-integrated circuit) bus.
10. The mobile communication terminal of claim 6 , wherein a communication between the distortion compensation processing unit and the ISP is conducted via an IIC bus.
11. The mobile communication terminal of claim 7 , wherein a communication between the distortion compensation processing unit and the ISP is conducted via an IIC bus.
12. The mobile communication terminal of claim 8 , wherein a communication between the distortion compensation processing unit and the ISP is conducted via an IIC bus.
13. The mobile communication terminal of claim 5 , wherein the back-end chip is a DSP (digital signal processor).
14. The mobile communication terminal of claim 6 , wherein the back-end chip is a DSP.
15. The mobile communication terminal of claim 7 , wherein the back-end chip is a DSP.
16. The mobile communication terminal of claim 8 , wherein the back-end chip is a DSP.
17. The mobile communication terminal of claim 5 , wherein the back-end chip is an MSM (mobile station modem).
18. The mobile communication terminal of claim 6 , wherein the back-end chip is an MSM.
19. The mobile communication terminal of claim 7 , wherein the back-end chip is an MSM.
20. The mobile communication terminal of claim 8 , wherein the back-end chip is an MSM.