Adaptive image improvement

• US 20060017773A1
• Filed: 01/03/2005
• Published: 01/26/2006
• Est. Priority Date: 07/26/2004
• Status: Active Grant

• Current Assignee: Rateze Remote Mgmt. L.L.C. (Intellectual Ventures LLC)
• Original Assignee: Somle Development LLC (Intellectual Ventures LLC)
• Inventors: Sheraizin, Vitaly S., Sheraizin, Semion M.
• Granted Patent: US 7,639,892 B2
• Time in Patent Office: Days
• US Class Current: 347/43
• CPC Class Codes: H04N 1/4092 Edge or detail enhancement
• CPC Class Codes: H04N 1/628 Memory colours, e.g. skin or sky

Abstract

A method includes improving an input image generally to compensate for the differences between how an image sensor views an object and how the human visual system views the object and generating a printout of the improved image at a faster print speed than that which would generate a printout of the input image. The improved image printout has at least the same or better visual quality than the input image printout. Improving the image includes analyzing an input image, reducing saturation levels for areas of human skin under low light exposures and improving the visual resolution of the input image.

Claims

1. A system comprising:

an adaptive image improver to receive an input image to be printed and to improve said image generally to compensate for the differences between how an image sensor views an object and how the human visual system views said object; and

a printer to generate a printout of said improved image at a faster print speed than that which would generate a printout of said input image, said improved image printout having at least the same visual quality level as said input image printout.

2. The system of claim 1 and wherein said printer comprises means for printing said improved image at a lower print resolution.

3. The system of claim 1 and wherein said adaptive image improver comprises:

an image analyzer to analyze an input image;

a skin processing unit to reduce saturation levels for areas of human skin under low light exposures; and

a visual resolution enhancer to improve the visual resolution of said input image.

4. The system according to claim 3 and wherein said image analyzer comprises units to determine locations of human skin, amount of texture, duration of edges and locations of bright light and low light in said input image.

5. The system according to claim 4 and wherein said system also comprises a controller to generate a low light skin mask, a texture threshold, per pixel sharpness coefficients, per pixel texture coefficients and per pixel skin coefficients from said output of said image analyzer.

6. The system according to claim 5 and wherein said controller is connected to said skin processing unit to provide said low light skin mask.

7. The system according to claim 5 and wherein said visual resolution enhancer comprises:

a sharpness enhancer to enhance sharpness of high frequency components of distinguishable small details using said per pixel sharpness coefficients; and

a sharpness controller to reduce sharpness levels for areas of human skin using said per pixel skin coefficients.

8. The system according to claim 7 and wherein said sharpness enhancer comprises a non-linear operator to reduce the intensity levels of said high frequency components of distinguishable small details, wherein said non-linear operator reduces high levels of said high frequency components more strongly than it reduces lower levels of said high frequency components.

9. The system according to claim 7 and wherein said visual resolution enhancer also comprises:

a texture limiter to limit high frequency components of said image to be no higher than said texture threshold; and

a texture modifier to modify said limited high frequency components using said per pixel texture coefficients.

10. The system according to claim 7 and wherein said visual resolution enhancer also comprises a noise reducer and wherein said noise reducer comprises a first low pass filter before said sharpness enhancer and a texture low pass filter after said texture modifier.

11. The system according to claim 10 and wherein said visual resolution enhancer comprises a horizontal high frequency channel and a vertical high frequency channel and wherein said texture limiter, texture modifier and texture low pass filter operate on both said horizontal and vertical channels.

12. The system according to claim 11 and wherein said texture low pass filter comprises a horizontal low pass filter in said vertical channel and a vertical low pass filter in said horizontal channel.

13. A method comprising:

receiving an input image to be printed;

improving said image generally to compensate for the differences between how an image sensor views an object and how the human visual system views said object; and

generating a printout of said improved image at a faster print speed than that which would generate a printout of said input image, said improved image printout having at least the same visual quality as said input image printout.

14. The method of claim 13 and wherein said generating comprises printing said improved image at a lower print resolution.

15. The method according to claim 13 and wherein said improving comprises:

analyzing an input image;

reducing saturation levels for areas of human skin under low light exposures; and

improving the visual resolution of said input image.

16. The method according to claim 15 and wherein said analyzing comprises determining locations of human skin, amount of texture, duration of edges and locations of bright light and low light in said input image.

17. The method according to claim 16 and also comprising generating a low light skin mask, a texture threshold, per pixel sharpness coefficients, per pixel texture coefficients and per pixel skin coefficients from said output of said analyzing.

18. The method according to claim 17 and wherein said generating comprises providing said low light skin mask to said step of reducing.

19. The method according to claim 17 and wherein said improving comprises:

enhancing sharpness of high frequency components of distinguishable small details using said per pixel sharpness coefficients; and

reducing sharpness levels for areas of human skin using said per pixel skin coefficients.

20. The method according to claim 19 and wherein said enhancing comprises reducing the intensity levels of said high frequency components of distinguishable small details by reducing high levels of said high frequency components more strongly than it reduces lower levels of said high frequency components.

21. The method according to claim 19 and wherein said improving also comprises:

limiting high frequency components of said image to be no higher than said texture threshold; and

modifying said limited high frequency components using said per pixel texture coefficients.

22. The method according to claim 19 and wherein said improving also comprises low pass filtering before said enhancing and texture low pass filtering after said modifying.

23. The method according to claim 22 and wherein said improving comprises a horizontal high frequency channel and a vertical high frequency channel and wherein said limiting, modifying and texture low pass filtering operate on both said horizontal and vertical channels.

24. The method according to claim 23 and wherein said texture low pass filtering comprises horizontal low pass filtering in said vertical channel and a vertical low pass filtering in said horizontal channel.