Background color conversion for toner-saving printing
A toner saving printing method and related computer program product is described. The program analyzes an input file to extract data that represents background, and if the background is a solid dark color, changes the background to a colorless or a lighter color background. The colors of the foreground objects such as text and graphics are changed correspondingly to maintain adequate contrast between the foreground objects and the background. The method can be implemented as a part of a printer driver.
1. A method implemented in a computer or printer for printing an input file, comprising:
(a) analyzing the input file to extract data representing a background;
(b) examining the data extracted in step (a) to determine a color of the background; and
(c) if and only if the color of the background is darker than a first threshold color value, changing the color of the background.
2. The method of claim 1 , wherein the input file contains code that specifies the background, and wherein step (a) comprises identifying the code in the input file that specifies the background.
3. The method of claim 1 , wherein the input file contains a bitmap image, and wherein step (a) comprises analyzing the bitmap image to determine the color of the background.
4. The method of claim 1 , wherein in step (c), the color of the background is changed to a white color.
5. The method of claim 1 , wherein in step (c), a saturation of the background color is changed.
6. The method of claim 1 , further comprising receiving a user input specifying whether the background color is to be removed.
7. The method of claim 1 , further comprising:
(d) if the color of the background is changed, determining a color of a foreground object in the input file; and
(e) if the color of the foreground object is lighter than a second threshold color value, darken the color of the foreground object.
8. The method of claim 7 , wherein the foreground object represents one of text object and graphics object.
9. The method of claim 7 , wherein the second threshold color value is equal to the first threshold color value.
10. The method of claim 1 , wherein step (a) further includes extracting data representing a foreground, the method further comprising temporarily storing the extracted background data and foreground data.
11. The method of claim 10 , wherein the foreground represents at least one of text and graphics.
12. A method implemented in a computer or printer for printing an input file, comprising:
(a) receiving a user input specifying a threshold color value;
(b) analyzing the input file to extract data representing a background;
(c) examining the data extracted in step (b) to determine a color of the background; and
(d) if and only if the color of the background is darker than a threshold color value, changing the color of the background.
13. A computer program product comprising a computer usable medium having a computer readable program code embedded therein for controlling a data processing apparatus, the computer readable program code configured to cause the data processing apparatus to execute a process for printing an input file, the process comprising:
(a) analyzing the input file to extract data representing a background;
(b) examining the data extracted in step (a) to determine a color of the background; and
(c) if and only if the color of the background is darker than a first threshold color value, changing the color of the background.
14. The computer program product of claim 13 , wherein the input file contains code that specify the background, and wherein step (a) comprises identifying the code in the input file that specify the background.
15. The computer program product of claim 13 , wherein the input file contains a bitmap image, and wherein step (a) comprises analyzing the bitmap image to determine the color of the background.
16. The computer program product of claim 13 , wherein in step (c), the color of the background is changed to a white color.
17. The computer program product of claim 13 , wherein in step (c), a saturation of the background color is changed.
18. The computer program product of claim 13 , wherein the process further comprises receiving a user input specifying whether the background color is to be removed.
19. The computer program product of claim 13 , wherein the process further comprises receiving a user input specifying the first threshold color value.
20. The computer program product of claim 13 , wherein the process further comprises:
(d) if the color of the background is changed, determining a color of a foreground object in the input file; and
(e) if the color of the foreground object is lighter than a second threshold color value, darken the color of the foreground object.
21. The computer program product of claim 20 , wherein the foreground object represents one of a text object and graphics object.
22. The computer program product of claim 20 , wherein the second threshold color value is equal to the first threshold color value.
23. The computer program product of claim 13 , wherein step (a) further includes extracting data representing a foreground, and wherein the process further comprises temporarily storing the extracted background data and foreground data.
24. The computer program product of claim 23 , wherein the foreground represents one of a text object and graphics object.