Method of image color correction

• US 20010048529A1
• Filed: 05/30/2001
• Published: 12/06/2001
• Est. Priority Date: 05/31/2000
• Status: Active Grant

• Current Assignee: Fotland, Richard A.
• Original Assignee: Fotland, Richard A.
• Inventors: Fotland, Richard A.
• Granted Patent: US 6,873,438 B2
• Time in Patent Office: Days
• US Class Current: 358/1.9
• CPC Class Codes: H04N 1/6011 with simulation on a subsidiary picture reproducer H04N1/622 takes precedence; matching two or more picture reproducers H04N1/6052

Abstract

Method of printer color error correction employing the rapid alternate viewing of a scanned original color image file and an image file formed by scanning an image printed by the printer whose error is to be corrected. Color errors appear as a blinking or flickering feature in the viewing monitor. Adjustments are made to the original color image file to eliminate or minimize flicker. The adjusted color file is then employed in printing a color corrected image. Another embodiment provides the method of the invention for real time color correction in images printed on conventional or digital printing presses.

Claims

1. A method of correcting color image reproduction errors in digital printing devices which includes the steps of:

digitally scanning an original image and storing the scanned data in a first digital file,

printing said first digital file employing the digital printing device whose errors are to be compensated thereby generating a color distorted print,

digitally scanning said color distorted print and storing the image in a second digital file,

alternately viewing the images stored in said first digital file and said second digital file on a display device,

adjusting the display size and position of said first and said second digital file so that the two images overlap,

adjusting the color parameters of hue, saturation, and brightness of said second image file to minimize color flicker and brightness flicker in the apparent image viewed in said display device, and

printing the adjusted aid second digital file to provide a duplicate color print that closely matches said original image.

2. The method of

claim 1

where said first digital file and said second digital file are each composed of four digital memory planes corresponding to the color information in the yellow, cyan, magenta, and black portions of said original and said duplicated color print.

3. The method of

claim 1

where the images stored in said first digital file are alternately viewed superimposed with the images stored in said second digital file at an alternating viewing frequency between about 0.2 and about 5 image changes per second.

4. The method of

claim 1

where the images stored in said first digital file and the images stored in said second digital file are both blurred to remove high frequency special components from appearing in said display device.

5. A method of correcting color reproducing errors in digital printing presses which includes the steps of:

digitally scanning an original image and storing the scanned data in both a digital reference image file and a digital printing press working image file

printing said digital printing press working image file thereby generating a color distorted print,

digitally scanning said color distorted print and storing the image in a digital temporary image file,

alternately viewing the images stored in said digital reference image file and said temporary digital image file on a display device,

adjusting the display size and position of said reference and said temporary digital image files so that the two images overlap,

adjusting the color parameters of hue, saturation, and brightness stored in said press working image file to minimize color flicker and brightness flicker in the apparent image viewed in said display device thereby providing a digital press printed duplicate color print that closely matches said original image.

6. The method of

claim 5

where said working image file, said reference image file, and said temporary image file are each composed of four digital memory planes corresponding to the color information in the yellow, cyan, magenta, and black portions of said original and said printed color print.

7. The method of

claim 5

where the images stored in said reference image file are alternately viewed superimposed with the images stored in said temporary image file at an alternating viewing frequency between about 0.2 and about 5 image changes per second.

8. The method of

claim 5

where the images stored in said reference image file and the images stored in said temporary image file are both blurred to remove high frequency special components from appearing in said display device.

9. The method of

claim 5

where the stored image in the temporary image file is periodically updated with a new digitally scanned image.

10. A method of correcting color reproducing errors in printing presses which includes the steps of:

digitally scanning an original image and storing the scanned data in a digital reference image file,

preparing and mounting press printing plates corresponding to the original image, printing reproductions of said original image,

digitally scanning said printed reproduction and storing said scanned image in a digital temporary image file,

alternately viewing the images stored in said digital reference image file and said temporary digital image file on a display device,

adjusting the display size and position of said reference and said temporary digital image files so that the two images overlap,

adjusting the inking and press process controls to minimize or eliminate flicker in said display device,

thereby providing press printed duplicate color prints that closely match said original image.

11. The method of

claim 10

where said reference image file and said temporary image file are each composed of four digital memory planes corresponding to the color information in the yellow, cyan, magenta, and black portions of said original and said printed reproduction.

12. The method of

claim 10

where the images stored in said reference image file are alternately viewed superimposed with the images stored in said temporary image file at an alternating viewing frequency between about 0.2 and about 5 image changes per second.

13. The method of

claim 10

where the images stored in said reference image file and the images stored in said temporary image file are both blurred to remove high frequency special components from appearing in said display device.

14. The method of

claim 10

where the stored image in the temporary image file is periodically updated with a new digitally scanned image.