Scanning and detecting a number of images

• US 20030059111A1
• Filed: 09/24/2002
• Published: 03/27/2003
• Est. Priority Date: 09/24/2001
• Status: Active Grant

• Current Assignee: Canon Information Systems Research Australia Pty Limited (Canon Inc.)
• Original Assignee: Canon Information Systems Research Australia Pty Limited (Canon Inc.)
• Inventors: Druitt, Colin Eric, Gallagher, Matthew William
• Granted Patent: US 7,149,349 B2
• Time in Patent Office: Days
• US Class Current: 382/173
• CPC Class Codes: H04N 1/38 Circuits or arrangements for blanking or otherwise eliminating unwanted parts of pictures H04N1/387 takes precedence
• CPC Class Codes: H04N 1/3872 Repositioning or masking

Abstract

The disclosed a number of methods for scanning and individually detecting a number of images on a scanner platen. In one method, the scanner scans the platen one scanline after another and performs the following steps for each scanline. The method first detects and groups together one or more consecutive pixels of a current scanline having substantially similar colours (804,808,806). The method then determines (826) those said groups of pixels of a current scanline which likely belong to images and those which likely belong to background of the scanner. The method then copies (708) the determined groups of pixels belonging to images of a current scanline to their respective images.

Claims

1. A method of scanning and individually detecting a number of images on a scanner, the method performing the following steps for a plurality of scanlines:

detecting and grouping together one or more consecutive pixels of a current scanline, wherein the pixels are grouped together based on a representation of said current scanline;

determining a current background colour of the scanner, wherein the current background colour is derived from a previously said determined background colour and a colour representative of that group of pixels of the current scanline most likely to be part of the background;

determining those said groups of pixel of a current scanline that are likely to belong to said images and those that are likely to belong to the background based upon said determined current background colour, and

copying said determined groups of pixels belonging to images of a current scanline to their respective images.

2. A method as claimed in claim 1, wherein the representation of the current scanline represents edges of a pixel image of the current scanline.

3. A method as claimed in claim 1, wherein the representation of the current scanline represents a pixel image of the current scanline.

22. An image file produced by any one of the methods as claimed in claims 1, 4 or 9.

4. A method of scanning and individually detecting a number of images on a scanner, the method performing the following steps for a plurality of scanlines:

detecting and grouping together one or more consecutive pixels of a current scanline having substantially similar colours;

determining a current background colour having a likelihood of being a background colour of the scanner, wherein the current background colour is derived from a previously said determined background colour and a colour representative of that group of pixels of the current scanline most likely to be part of the background colour;

determining those said groups of pixels of a current scanline that are likely to belong to said images and those that are likely to belong to the background based upon said determined current background colour, and

copying said determined groups of pixels belonging to images of a current scanline to their respective images.

5. A method as claimed in claim 4, wherein said step of determining said groups of pixels comprises the sub-step of:

comparing said groups of pixels of said current scanline with said determined current background colour, wherein if any one of said groups of pixels are substantially similar in colour to the current background colour marking those groups as belonging to said background otherwise marking any one of said groups of pixels that are not substantially similar in colour to the current background colour as belonging to said images.

6. A method as claimed in claim 4, wherein said step of determining the current background colour comprises the sub-steps of:

determining a value representative of the current background colour based on a value of the previously determined background colour, a value representative of the certainty that said determined value of the current background colour will be correct, and the colour of that group of pixels of the current scanline most likely as being part of the background.

7. A method as claimed in claim 4, wherein said step of determining the current background colour comprises the substeps of:

(a) performing the following sub-steps for each of said group of pixels of the current scanline;

(a)(1) determining a value representative of the likelihood that the group of pixels belongs to the background based on the number of pixels in the group;

(a)(2) determining a value representative of the likelihood that the group of pixels belongs to the background based on the colour of the pixels of the group with reference to the previously determined background colour; and

(a)(3) determining a value representative of the likelihood that the group of pixels belongs to the background based on the previous likelihood values determined during steps a(1) and a(2), and a value representative of the certainty that the previously determined background colour is correct;

(b) performing the following sub-steps once for the current scanline;

(b)(1) determining the maximum of the likelihood values determined by step a(3) for the groups of pixels for the current scanline;

(b)(2) setting the certainty value to said maximum value determined during step (b)(1); and

(b)(2) determining the current background colour based on the colour of the pixels of the group of pixels having a maximum likelihood value determined by step (b)(1), the previously defined background colour, and the certainty value set during step (b)(2); and

wherein said step of determining said groups of pixels comprises the sub-step of;

(c) comparing said groups of pixels of said current scanline with said determined current background colour, wherein if any one of said groups of pixels are substantially similar in colour to the current background colour marking those groups as belonging to said background otherwise marking any one of said groups of pixels that are not substantially similar in colour to the current background colour as belonging to said images.

8. A method as claimed in claim 4, wherein said respective images are individually de-skewed, clipped and saved to disk as separate image files.

9. A method of scanning and individually detecting a number of images on a scanner, the method performing the following steps for a plurality of scanline:

pre-processing a current scanline to provide a current pre-processed scanline, wherein the current pre-processed scanline is representative of edges of a pixel image of the current scanline;

detecting and grouping together one or more consecutive pixels of the current pre-processed scanline, wherein those pixels of the current pre-processed scanline having values below a predetermined threshold value are grouped together in a group;

determining a current background colour having a likelihood of being a background colour of the scanner, wherein the current background colour is derived from a previously said determined background colour and a colour representative of a group of pixels of the current scanline corresponding to the said group of pixels of the current pre-processed scanline having values below the predetermined threshold;

determining those said groups of pixels of a current scanline that are likely to belong to said image and those that are likely to belong to the background based upon said determined current background colour; and

copying said determined groups of pixels belonging to images of a current scanline to their respective images.

10. Apparatus for scanning and individually detecting a number of images on a scanner, the apparatus comprising:

processing means for processing a plurality of scanlines, the processing means comprising;

means for detecting and grouping together one or more consecutive pixels of a current scanline, wherein the pixels are grouped together based on a representation of said current scanline;

means for determining a current background colour of the scanner, wherein the current background colour is derived from a previously said determined background colour and a colour representative of that group of pixels of the current scanline most likely to be part of the background;

means for determining those said groups of pixels of a current scanline that are likely to belong to said images and those that are likely to, belong to the background based upon said determined current background colour; and

means for copying said determined groups of pixels belonging to images of a current scanline to their respective images.

11. Apparatus as claimed in claim 10, wherein the representation of the current scanline represents the edges of a pixel image of the current scanline.

12. Apparatus as claimed in claim 10, wherein the representation of the current scanline represents a pixel image of the current scanline.

13. Apparatus for scanning and individually detecting a number of images on a scanner, the apparatus comprising:

processing means for processing a plurality of scanlines, the processing means comprising;

means for detecting and grouping together one or more consecutive pixels of a current scanline having substantially similar colours;

means for determining a current background colour having a likelihood of being a background colour of the scanner, wherein the current background colour is derived from a previously said determined background colour and a colour representative of that group of pixels of the current scanline most likely to be part of the background colour;

means for determining those said groups of pixels of a current scanline that are likely to belong to said images and those that are likely to belong to the background based upon said determined current background colour, and

means for copying said determined groups of pixels belonging to images of a current scanline to their respective images.

14. Apparatus as claimed in claim 13, wherein said means for determining said groups of pixels comprises:

means for comparing said groups of pixels of said current scanline with said determined current background colour, wherein if any one of said groups of pixels are substantially similar in colour to the current background colour marking those groups as belonging to said background otherwise marking any one of said groups of pixels that are not substantially similar in colour to the current background colour as belonging to said images.

15. Apparatus as claimed in claim 13, wherein said means for determining the current background colour comprises:

means for determining a value representative of the current background colour based on a value of the previously determined background colour, a value representative of the certainty that said determined value of the current background colour will be correct, and the colour of that group of pixels of the current scanline most likely as being part of the background.

16. Apparatus as claimed in claim 13, wherein said means for determining the current background colour comprises:

processing means for processing each of said group of pixels of the current scanline, the processing means comprising;

first determination means for determining a value representative of the likelihood that the group of pixels belong to the background based on the number of pixels in the group;

second determination means for determining a value representative of the likelihood that the group of pixels belongs to the background based on the colour of the pixels of the group with reference to the previously determined background colour; and

third determination means for determining a value representative of the likelihood that the group of pixels belongs to the background based on the previous likelihood value determined by said first and second means, and a value representative of the certainty that the previously determined background colour is correct;

processing means for processing the current scanline, the processing means comprising;

fourth determination means for determining the maximum of the likelihood values determined by the third determination means for the groups of pixels for the current scanline;

means for setting the certainty value to said maximum value determined by said fourth determination means; and

fifth determination means for determining the current background colour based on the colour of the pixels of the group of pixels having a maximum likelihood value determined by the fourth determination means, the previously determined background colour, and the certainty value set by the setting means;

and wherein said means for determining said groups of pixels comprises;

means for comparing said groups of pixels of said current scanline with said determined current background colour, wherein if any one of said groups of pixels are substantially similar in colour to the current background colour marking those groups as belonging to said background otherwise marking any one of said groups of pixels that are not substantially similar in colour to the current background colour as belonging to said images.

17. Apparatus as claimed in claim 13, wherein said respective images are individually de-skewed, clipped and saved to disk as separate image files.

18. Apparatus for scanning and individually detecting a number of images on a scanner, the apparatus comprising:

processing means for processing a plurality of scanlines, the processing means comprising;

means for pre-processing a current scanline to provide a current pre-processed scanline, wherein the current pre-processed scanline is representative of edges of a pixel image of the current scanline;

means for detecting and grouping together one or more consecutive pixels of the current pre-processed scanline, wherein those pixels of the current pre-processed scanline having values below a predetermined threshold value are grouped together in a group;

means for determining a current background colour having a likelihood of being a background colour of the scanner, wherein the current background colour is derived from a previously said determined background colour and a colour representative of a group of pixels of the current scanline corresponding to the said group of pixels of the current pre-processed scanline having values below the predetermined threshold;

means for determining those said groups of pixels of a current scanline that are likely to belong to said images and those that are likely to belong to the background based upon said determined current background colour; and

means for copying said determined groups of pixels belong to images of a current scanline to their respective images.

19. A computer program for scanning and individually detecting a number of images on a scanner, the computer program comprising:

processing means for processing a plurality of scanlines, the processing means comprising;

means for detecting and grouping together one or more consecutive pixels of a current scanline, wherein the pixels are grouped together based on a representation of said current scanline;

means for determining a current background colour of the scanner, wherein the current background colour is derived from a previously said determined background colour and a colour representative of that group of pixels of the current scanline most likely to be part of the background;

means for determining those said groups of pixels of a current scanline that are likely to belong to said images and those that are likely to belong to the background based upon said determined current background colour; and

means for copying said determined groups of pixels belonging to images of a current scanline to their respective images.

20. A computer program for scanning and individually detecting a number of images on a scanner, the computer program comprising:

processing means for processing a plurality of scanlines, the processing means comprising;

means for detecting and grouping together one or more consecutive pixels of a current scanline having substantially similar colours;

means for determining a current background colour having a likelihood of being a background colour of the scanner, wherein the current background colour is derived from a previously said determined background colour and a colour representative of that group of pixels of the current scanline most likely to be part of the background colour;

means for determining those said groups of pixels of a current scanline that are likely to belong to said images and those that are likely to belong to the background based upon said determined current background colour; and

means for copying said determined groups of pixels belonging to images of a current scanline to their respective images.

21. A computer program for scanning and individually detecting a number of images on a scanner, the computer program comprising:

processing means for processing a plurality of scanlines, the processing means comprising;

means for pre-processing a current scanline to provide a current pre-processed scanline, wherein the current pre-processed scanline is representative of edges of a pixel image of the current scanline;

means for detecting and grouping together one or more consecutive pixels of the current pre-processed scanline wherein those pixels of the current pre-processed scanline having values below a predetermined threshold value are grouped together in a group;

means for determining a current background colour having a likelihood of being a background colour of the scanner, wherein the current background colour is derived from a previously said determined background colour and a colour representative of a group of pixels of the current scanline corresponding to the said group of pixels of the current pre-processed scanline having values below the predetermined threshold;

means for determining those said groups of pixels of a current scanline that are likely to belong to said images and those that are likely to belong to the background based upon said determined current background colour; and

means for copying said determined groups of pixels belonging to images of a current scanline to their respective images.