Compressing and uncompressing method for high bit-depth medical gray scale images

• US 10,672,148 B2
• Filed: 10/27/2016
• Issued: 06/02/2020
• Est. Priority Date: 10/30/2015
• Status: Active Grant

• Current Assignee: AGFA Healthcare NV (Agfa-Gevaert N.V.)
• Original Assignee: AGFA Healthcare NV (Agfa-Gevaert N.V.)
• Inventors: Mroz, Lukas
• Primary Examiner(s): Desire, Gregory M
• Application Number:
  US15/771,414
• Publication Number:
  US 20180315215A1
• Time in Patent Office: 1,314 Days
• CPC Class Codes: G06T 11/001 Texturing; Colouring; Generation of texture or colour inpainting G06T5/77
• CPC Class Codes: G06T 2210/41 Medical
• CPC Class Codes: G06T 9/00 Image coding bandwidth or redundancy reduction for static pictures H04N1/41; coding or decoding of static colour picture signals H04N1/64; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00
• CPC Class Codes: G16H 30/20 for handling medical images, e.g. DICOM, HL7 or PACS
• CPC Class Codes: H04N 1/41 Bandwidth or redundancy reduction by scanning H04N1/17 ; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00
• CPC Class Codes: H04N 1/465 Conversion of monochrome to colour
• CPC Class Codes: H04N 19/117 Filters, e.g. for pre-processing or post-processing sub-band filter banks H04N19/635
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/196 being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters processing of motion vectors H04N19/513

Abstract

A digital encoding and decoding method of high bit-depth gray scale medical images allows standard 3-channel color image compression algorithms to be used to compress and de-compress such encoded high bit-depth gray scale images without significant image quality loss. The digital encoding and decoding method may be used to improve the network transmission, storage and rendering of such gray scale images in a standard web browser.

Claims

1. A method for encoding and compressing a single channel digital n-bit gray scale image data stream, in which 9≤

n≤

24, into an 8-bit RGB encoded image data stream, the method comprising the steps of;

sequentially accessing each of a plurality of gray scale image data pixels of the digital n-bit gray scale image data stream;

applying three mathematical transformations to each of a plurality of n-bit luminance values retrieved from the plurality of gray scale image data pixels;

storing results of the three mathematical transformations into three 8-bit sub-pixel memory locations as 8-bit RGB encoded image data pixels;

sequentially outputting the 8-bit RGB encoded image data pixels as the 8-bit RGB encoded image data stream; and

compressing the 8-bit RGB encoded image data stream using a JPEG standard;

wherein

the three mathematical transformations are defined as;

2. An image processing apparatus comprising:

a bit-stream storage that stores an n-bit image data stream; and

an image processor that communicates with the bit-stream storage;

wherein

the image processor is configured or programmed to perform the steps of the method according to claim 1.

3. A non-transitory computer readable medium comprising data stored on the non-transitory computer readable medium that, when interpreted and executed by a computer, includes a bit-stream storage that stores an n-bit image data stream and an image processor that communicates with the bit-stream store and performs the steps of the method according to claim 1.

4. A method for uncompressing and decoding a single channel digital n-bit gray scale image data stream, in which 9≤

n≤

24, from an 8-bit RGB encoded image data stream, the method comprising the steps of;

sequentially accessing three sub-pixel values stored in each of a plurality of 8-bit RGB image data pixels of the 8-bit RGB encoded image data stream;

uncompressing the 8-bit RGB encoded image data stream using a JPEG standard;

applying a mathematical transformation to the three sub-pixel values;

storing a result of the mathematical transformation in a single channel n-bit gray scale image data pixel; and

sequentially outputting n-bit image pixels as a high quality gray scale image data stream;

wherein

the mathematical transformation applied to the three sub-pixel values is defined as;

5. An image processing apparatus comprising:

a bit-stream storage that stores an 8-bit RGB encoded image data stream; and

an image processor that communicates with the bit-stream storage;

wherein

the image processor is configured or programmed to perform the steps of the method according to claim 4.

6. A non-transitory computer readable medium comprising data stored on the non-transitory computer readable medium that, when interpreted and executed by a computer, includes a bit-stream storage that stores an 8-bit RGB encoded image data stream and an image processor that communicates with the bit-stream storage and performs the steps of the method according to claim 4.