Method for reordering the pixel map of a digitized image

• US 5,007,001 A
• Filed: 01/24/1990
• Issued: 04/09/1991
• Est. Priority Date: 01/24/1990
• Status: Expired due to Fees

• Current Assignee: Andrew Lloyd-Williams
• Original Assignee: Andrew Lloyd-Williams
• Inventors: Lloyd-Williams, Andrew
• Primary Examiner(s): Clark, David L.
• Application Number:
  US07/469,340
• Time in Patent Office: 440 Days
• Field of Search: 364/518, 364/521, 364/522, 382/47, 382/56, 358/426
• US Class Current: 345/428
• CPC Class Codes: H04N 19/00 Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
• CPC Class Codes: H04N 19/63 using sub-band based transform, e.g. wavelets
• CPC Class Codes: H04N 19/98 Adaptive-dynamic-range coding [ADRC]
• CPC Class Codes: H04N 7/24 Systems for the transmission of television signals using pulse code modulation H04N21/00 takes precedence

Abstract

A method for reordering the pixel map of a multi-dimensional image by representing each pixel address as a unique set of coordinates in binary reprsentation, reversing the bit order for each coordinate, interleaving the binary digits of the numbers thus formed from each coordinate in a consistent bit-by-bit fashion, and using the composite binary number thus formed as a new pixel sequence number; storage and/or subsequent transmission of pixel values then takes place in order of ascending pixel sequence numbers, omitting numbers representing pixels outside the limits of the selected image.

Claims

1. A computer-implemented method of reordering a pixel map of a multi-dimensional digitized image to provide a new pixel order which approximates to a situation in which any contiguous subset of the reordered pixel map represents all regions of the image, with broader detail being depicted first, followed by increasingly fine detail, the method comprising:

(a) establishing a coordinate system and an origin for that coordinate system which provides for each pixel displacement coordinates represented by a set of positive integer values, each pixel being represented by only one such set of values and each set of coordinate values representing at most one pixel position;

(b) for each pixel in the image;

(i) establishing attributes of the pixel;

(ii) establishing a position within the overall image, and representing this position in the form of a set of coordinates relative to the origin;

(iii) converting each coordinate value in said set of coordinates to a binary repreesentation of 0'"'"'s and 1'"'"'s, with the inclusion of leading zeroes to ensure that all representations of that coordinate are of equal length;

(iv) for each coordinate in the set of coordinates, reversing the bit stream thus formed;

(v) interleaving the reversed bit streams representing each coordinate in a bit-wise fashion to form a pixel sequence number;

(c) reordering the storage or transmission of the attribute values corresponding to each pixel in the order of ascending pixel sequence numbers.

2. A method according to claim 1, wherein said coordinates are represented by Cartesian coordinates.

3. A method according to claim 1, wherein said image is two-dimensional and said coordinates are represented as (Z,Y) where (X,Y) represents the pixel position within the image in Cartesian coordinates and Z is formed by the bit-wise logical `EXCLUSIVE OR` of X and Y, discarding those bits, if any, with greater significance than is required to represent all possible values of X.

4. A method according to claim 1, wherein said image is in color with pixel attributes represented by Red/Green/Blue values, Hue/Saturation/Intensity values or other equivalent components.

5. A method according to claim 1, wherein said pixel attributes are represented by an offset into a predefined color map.

6. A method according to claim 1, wherein a random access memory buffer of limited size is utilized to perform efficient reordering of pixel attributes preparatory to transmission or output to a new file.

7. A method according to claim 1, wherein one or more lookup tables are created for performing said reversals of bit-streams.

8. A method according to claim 7, wherein said lookup tables are adjusted to provide scaling of said image to display at resolutions or in perspectives other than that of the original digitized image.

9. A method according to claim 8, further comprising the step of limiting the display to a sub-area of the overall image, by omitting display pixels outside that sub-area.

10. A method according to claim 9, further comprising providing an elastic box superimposed on the display for operator selection of a sub-area of the currently displayed area for enlarged display, or reversion to display the overall image or of a previously displayed area.

11. A method according to claim 9, further comprising wholly or partially clearing said image and adding a new display depicting a different selected sub-area and/or with different scaling.

12. A method according to claim 1, further comprising suspending image transmission from a sending station to a receiving station at any time on request from the receiving station.

13. A method according to claim 12, further comprising following suspension of image transmission, the receiving station requesting continued transmission of a defined sub-area of the overall image, and transmission of such sub-area then proceeds without retransmission of information already received or transmission of information not pertaining to the selected sub-area.

14. A method according to claim 13, further comprising separation of the image into a high definition region and a low definition region and the storage and/or transmission firstly of a recorded pixel map representing the entire image at low definition followed by storage and/or transmission of a reordered pixel map representing only the high definition region at high definition omitting data already included in the first data stream.

15. A method according to claim 1, wherein reordering and subsequent storage or transmission of said pixel map is performed on a digitized image, consisting of separate, contiguous, rectangular sections, each of which is represented by all or a portion of a separate input stream.

16. A method according to claim 1, wherein image files stored as reordered pixel maps are effectively and repeatedly archived by means of a simple truncation of the file with consequent loss of detail, but without total loss of any part of the original image.

17. A method according to claim 1, further comprising displaying said image from the reordered pixel map as a mosaic of tiles, each tile consisting of an area of pixels all displaying the same attributes, the first tile filling the entire display area, and subsequent tiles repeatedly overlaying existing tiles with tiles of a consistent size, before proceeding with tiles of a smaller size, until finally tiles consist of individual pixels.

18. A method according to claim 17, wherein the displayable attributes of each tile are determined to be the average value of the original attributes of the pixels falling within the tile, as read from the original image data stream, and such displayable attributes for each tile are represented in the reordered pixel map by the difference between the value of said displayable attributes and the value of the displayable attributes for the larger previously displayed tile which is to be overlaid by said tile.

19. A method according to claim 18, further comprising the step of compacting the data stream representing the differences in average values of attributes of successive tiles, in a manner that imposes substantially greater compaction on later segments of the data stream, which represent increasingly finer detail and are expected to have, or may be forced to have a smaller range than is present in the earlier segments of the data stream.

20. A method according to claim 1, further comprising storage and/or transmission of image sequences by storing and/or transmitting as much data as is possible in the time available between successive frames and then beginning transmission of the following frame omitting data pertaining to regions of the image that are unchanged relative to the previous frame.