Method and data arrangement for encapsulating signed over-ranged color image data to accommodate in-range file formats

• US 20010033286A1
• Filed: 02/22/2001
• Published: 10/25/2001
• Est. Priority Date: 02/25/2000
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Stokes, Michael D., Wong, Gilman K.
• Granted Patent: US 6,611,273 B2
• Time in Patent Office: Days
• US Class Current: 345/590
• CPC Class Codes: H04N 1/64 Systems for the transmission or the storage of the colour picture signal; Details therefor, e.g. coding or decoding means therefor H04N19/00 takes precedence

Abstract

A new method and data encapsulation arrangement are disclosed for over-ranging color image data. The resulting data storage format renders color image data sets encoded in the over-ranging format compatible with in-range color image systems. Thus, color images including over-ranging portions will be readable by legacy systems that handle only in-range color data.

The new arrangement of the color image data storage comprises a file header segment describing contents of a color image file. The new arrangement also includes an image data segment comprising digital image data representing a set of color image elements encoded in a signed over-ranged color space. A multi-partitioned color image bitmap data segment is created.

A first partition in the multi-partitioned bitmap data segment includes image data corresponding to a first color image data word portion associated with an in-range color space. A second partition in the multi-partitioned bitmap data segment includes image data corresponding to a second color image data word portion associated with an over-ranging color space. The second partition may optionally include additional precision bits that are concatenated with the lowest precision in-range color channel data of the first partition.

Claims

1. A color image data storage arrangement for encapsulating over-ranging color image data in a format rendering color image data sets encoded in the over-ranging format compatible with in-range color image systems, the color image data storage arrangement comprising:

a file header segment describing contents of a color image file; and

an image data segment comprising digital image data representing a set of color image elements encoded in a signed over-ranged color space, the image data segment comprising;

a first partition comprising image data corresponding to a first color image data word portion associated with an in-range color space; and

a second partition comprising image data corresponding to a second color image data word portion associated with an over-ranging color space.

2. The color image data storage arrangement of

claim 1

wherein the first color image data word portion comprises lowest precision, in-range color data.

3. The color image data storage arrangement of

claim 2

wherein the lowest precision in-range color data corresponds to in-range 8-bit sRGB data.

4. The color image data storage arrangement of

claim 2

wherein the second partition further comprises image data corresponding to a third color image data word portion associated with the in-range color space, the third color image data word portion supplementing a precision of in-range color data in the first color image data word portion.

5. The color image data storage arrangement of

claim 1

wherein the second color image data word portion comprises a sign bit.

6. The color image data storage arrangement of

claim 1

wherein the file header segment includes a second partition start address value corresponding to a logical memory location differing from a first partition start address.

7. The color image data storage arrangement of

claim 1

wherein image file data segment further comprises a third partition comprising image data corresponding to a third color image data word portion associated with the in-range color space, the third color image data word portion supplementing a precision of in-range color data in the first color image data word portion.

8. A method for arranging image data in an over-ranging color space in a format rendering color image data sets encoded in the over-ranging format compatible with in-range color image systems, the method comprising the steps of:

formulating a file header segment describing contents of a color image file; and

creating an image data segment comprising digital image data representing a set of color image elements encoded in a signed over-ranged color space, the creating an image data segment comprising the sub-steps of;

first storing image data corresponding to a first color image data word portion associated with an in-range color space within a first partition; and

second storing image data corresponding to a second color image data word portion associated with an over-ranging color space in a second partition.

9. The method of

claim 8

wherein the first color image data word portion comprises lowest precision, in-range color data.

10. The method of

claim 9

wherein the lowest precision in-range color data corresponds to in-range 8-bit sRGB data.

11. The method of

claim 9

wherein the second partition further comprises image data corresponding to a third color image data word portion associated with the in-range color space, the third color image data word portion supplementing a precision of in-range color data in the first color image data word portion.

12. The method of

claim 8

wherein the second color image data word portion comprises a sign bit.

13. The method of

claim 8

wherein the file header segment includes a second partition start address value corresponding to a logical memory location differing from a first partition start address.

14. The method of

claim 8

further comprising the step of:

third storing image data corresponding to a third color image data word portion associated with the in-range color space in a third partition, wherein the third color image data word portion supplements a precision of in-range color data in the first color image data word portion.

15. A color image data encoder for arranging image data in an over-ranging color space in a format rendering color image data sets encoded in the over-ranging format compatible with in-range color image systems, the color image data encoder comprising:

a first routine for formulating a file header segment describing contents of a color image file; and

a second routine for creating an image data segment comprising digital image data representing a set of color image elements encoded in a signed over-ranged color space, the creating an image data segment comprising;

first storing image data corresponding to a first color image data word portion associated with an in-range color space within a first partition; and

second storing image data corresponding to a second color image data word portion associated with an over-ranging color space in a second partition.

16. The encoder of

claim 15

wherein the first color image data word portion comprises lowest precision, in-range color data.

17. The encoder of

claim 16

wherein the second partition further comprises image data corresponding to a third color image data word portion associated with the in-range color space, the third color image data word portion supplementing a precision of in-range color data in the first color image data word portion.

18. The encoder of

claim 15

wherein the second color image data word portion comprises a sign bit.

19. The encoder of

claim 15

wherein the file header segment includes a second partition start address value corresponding to a logical memory location differing from a first partition start address.

20. A decoder for rendering color image data from a color image file comprising image data encoded in an over-ranging color space, in a format rendering color image data sets encoded in the over-ranging format compatible with in-range color image systems, the decoder comprising:

a first parsing routine for decoding a file header segment describing contents of a color image file; and

a second parsing routine for decoding an image data segment comprising digital image data representing a set of color image elements encoded in a signed over-ranged color space, the decoding an image data segment comprising;

first retrieving image data corresponding to a first color image data word portion associated with an in-range color space within a first partition; and

second retrieving image data corresponding to a second color image data word portion associated with an over-ranging color space in a second partition.

21. The decoder of

claim 20

wherein the first color image data word portion comprises lowest precision, in-range color data.

22. The decoder of

claim 21

wherein the second partition further comprises image data corresponding to a third color image data word portion associated with the in-range color space, the third color image data word portion supplementing a precision of in-range color data in the first color image data word portion.

23. The decoder of

claim 20

wherein the second color image data word portion comprises a sign bit.

24. The decoder of

claim 20

wherein the file header segment includes a second partition start address value corresponding to a logical memory location differing from a first partition start address.

25. A computer-readable medium storing computer executable instructions to perform steps for arranging image data in an over-ranging color space in a format rendering color image data sets encoded in the over-ranging format compatible with in-range color image systems, the steps comprising:

formulating a file header segment describing contents of a color image file; and

creating an image data segment comprising digital image data representing a set of color image elements encoded in a signed over-ranged color space, the creating an image data segment comprising the sub-steps of;

first storing image data corresponding to a first color image data word portion associated with an in-range color space within a first partition; and

second storing image data corresponding to a second color image data word portion associated with an over-ranging color space in a second partition.

26. The computer-readable medium of

claim 25

wherein the first color image data word portion comprises lowest precision, in-range color data.

27. The computer-readable medium of

claim 26

wherein the lowest precision in-range color data corresponds to in-range 8-bit sRGB data.

28. The computer-readable medium of

claim 26

wherein the second partition further comprises image data corresponding to a third color image data word portion associated with the in-range color space, the third color image data word portion supplementing a precision of in-range color data in the first color image data word portion.

29. The computer-readable medium of

claim 25

wherein the second color image data word portion comprises a sign bit.

30. The computer-readable medium of

claim 25

wherein the file header segment includes a second partition start address value corresponding to a logical memory location differing from a first partition start address.

31. The computer-readable medium of

claim 25

further comprising computer-executable instructions for performing the step of:

third storing image data corresponding to a third color image data word portion associated with the in-range color space in a third partition, wherein the third color image data word portion supplements a precision of in-range color data in the first color image data word portion.