Automated quality assurance image processing system

• US 5,537,483 A
• Filed: 12/14/1993
• Issued: 07/16/1996
• Est. Priority Date: 10/03/1989
• Status: Expired due to Fees

• Current Assignee: StapleVision, Inc. (DCI Telecommunications, Inc.)
• Original Assignee: StapleVision, Inc. (DCI Telecommunications, Inc.)
• Inventors: Lord, Christopher, Stapleton, John J.
• Primary Examiner(s): Mancuso, Joseph
• Application Number:
  US08/166,801
• Time in Patent Office: 945 Days
• Field of Search: 382/18, 382/51, 382/56, 382/57, 382/1, 358/403, 358/405, 358/462, 358/404, 364/552, 364/554
• US Class Current: 382/309
• CPC Class Codes: H04N 1/00002 Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for error detection, error correction or monitoring in digital computers or digital computer components G06F11/00
• CPC Class Codes: H04N 1/00005 relating to image data
• CPC Class Codes: H04N 1/0001 Transmission systems or arrangements
• CPC Class Codes: H04N 1/00013 Reading apparatus
• CPC Class Codes: H04N 1/00029 Diagnosis, i.e. identifying a problem by comparison with a normal state
• CPC Class Codes: H04N 1/00034 Measuring, i.e. determining a quantity by comparison with a standard H04N1/00031 takes precedence
• CPC Class Codes: H04N 1/00039 Analysis, i.e. separating and studying components of a greater whole
• CPC Class Codes: H04N 1/00047 using an image not specifically designed for the purpose
• CPC Class Codes: H04N 1/0005 in service, i.e. during normal operation
• CPC Class Codes: H04N 1/00063 using at least a part of the apparatus itself, e.g. self-testing
• CPC Class Codes: H04N 1/00068 Calculating or estimating
• CPC Class Codes: H04N 1/00071 characterised by the action taken
• CPC Class Codes: H04N 1/00082 Adjusting or controlling interrupting an operation H04N1/00915; inhibiting an operation H04N1/00925
• CPC Class Codes: H04N 1/32641 of transmission or transmitted data, e.g. interruption or wrong number of pages
• CPC Class Codes: H04N 1/32678 Performing substitution, e.g. substitute reception or substituting a corrupted line of data H04N1/32384 takes precedence
• CPC Class Codes: H04N 1/40 Picture signal circuits H04N1/387 takes precedence

Abstract

An image processing system with a quality assurance feature is disclosed for determining the quality of the images being processed. The system includes a plurality of sections operating independently and concurrently to insure reliability. One section includes calculation of a quality assurance parameter dependent on the fill factor and the compression ratio determined before and after compression respectively. A second section includes histogram hardware for generating qualified histograms representative of foreground data, and background data transitions and a comparator for detecting overlap therebetween. A third section develops a histogram parameter based on the areas of the histograms and compares this parameter to the quality assurance parameter for concurrence. The system also includes autosizing means for detecting the borders of an image using fuzzy logic.

Claims

1. An image processing system for automated quality control of converting optical images into corresponding digital data, said system comprising:

(a) sensing means for discriminating digital sensor signals corresponding to an image differential density of an image having a number of black bits (b) said digital sensor signals having a fill factor;

(b) means for generating a quality quotient of black bits (b)/compressed bits (c);

(c) compressing means for compressing said digital sensor signals to generate compressed signals, said compressed signals comprising (c) bits per image and defining a compression ratio, wherein a product of said compression ratio and said fill factor which is equal to a quality quotient of b/c, said quotient being related to resolution and quality of information rather than quantity of information in said image; and

(d) quality assurance means coupled to said sensing means and said compressing means for generating a quality assurance parameter dependent on said fill factor and said compression ratio, said quality assurance parameter being indicative of the quality of said image.

2. The image processing system of claim 1 wherein said quality assurance parameter is related to the product of said fill factor and compression ratio which is equal to the quality quotient of b/c.

3. The image processing system of claim 1 further including statistical and adaptive means for rejecting images in accordance with deviations of said quality assurance parameter from statistical norms.

4. The image processing system of claim 1 wherein said quality assurance means includes histogram hardware means for generating histograms corresponding to image background data, foreground data, single isolated pixel noise and edge transitions, and histogram analyzer means for analyzing said histograms.

5. The image processing system of claim 4 wherein histogram hardware means includes means for deconvolving a video histogram representative of an image into a plurality of qualified histograms representative respectively of background data, foreground data, single isolated pixel noise and edge transitions.

6. The image processing system of claim 5 further comprising means for verifying said quality assurance parameter including generating means for generating a histogram parameter dependent on acceptable values of edge transitions and raise.

7. The image processing system of claim 6 wherein said histogram parameter is related to one of:

(a) compression ratio and ratio of a sum of areas of histograms representative of background and foreground data to a sum of areas of the histograms representative of edge transitions and (b) the ratio of b/c estimated by the ratio of histograms areas of foreground data to histogram areas representative of edge transitions which are proportional to the compression ratio.

8. The image processing system of claim 1 wherein said compression means also includes decompressing means for decompressing said digital sensor signals to generate signals.

9. An image processing system for automated quality control of converting optical images into corresponding digital data, said system comprising:

(a) sensing means for discriminating digital sensor signals corresponding to an image differential density of an image of black bits (b) said digital sensor signals having a fill factor;

(b) compressing means for compressing said digital sensor signals to generate compressed signals, said compressed signals comprising (c) bits per image and defining compression ratio, wherein a product of said compression ratio and said fill factor which is equal to a quality quotient of b/c, said quality quotient being related to resolution and quality of information rather than quantity of information in said image;

(c) histogram hardware means coupled to said compression means for generating histograms corresponding to said image, and histogram analyzer means for analyzing said histograms wherein said histogram hardware means includes means for deconvolving a video histogram representative of an image into a plurality of qualified histograms representative respectively of background data, foreground data, and signal isolated pixel noise and edge transitions; and

(d) means for verifying a quality assurance parameter based upon comparable data from the histograms.

10. The image processing system of claim 9 wherein said histogram hardware means includes computing means for computing said histograms in real time, percentile means for sectioning said histograms into areas, and overlap detect means for rejecting overlap between percentiles of the background data histogram and the foreground data histogram by calculating diminishing gaps between percentiles.

11. The image processing system of claim 9 wherein said compression means also includes decompressing means for decompressing said digital sensor signals to generate signals.