Apparatus and method for spacial scan modulation of a video display

• US 5,424,780 A
• Filed: 09/13/1993
• Issued: 06/13/1995
• Est. Priority Date: 05/22/1989
• Status: Expired due to Term

• Current Assignee: Technology Licensing Corporation
• Original Assignee: James C. Cooper
• Inventors: Cooper, James C.
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): GRANT, CHRISTOPHER C
• Application Number:
  US08/119,610
• Time in Patent Office: 638 Days
• Field of Search: 348/615, 348/561, 348/581, 348/448, 348/443, 348/458, 348/428, 358/11
• US Class Current: 348/428.1
• CPC Class Codes: H04N 1/113 using oscillating or rotating mirrors
• CPC Class Codes: H04N 1/409 Edge or detail enhancement; Noise or error suppression
• CPC Class Codes: H04N 3/26 Modifications of scanning arrangements to improve focusing
• CPC Class Codes: H04N 3/34 Elemental scanning area oscillated rapidly in direction transverse to main scanning direction
• CPC Class Codes: H04N 7/0135 involving interpolation processes interpolation-based image scaling G06T3/4007; interpolation for video coding H04N19/587, H04N19/59

Abstract

An apparatus and method is shown for modifying the presentation of pixels displayed or printed on a raster or matrix image or graphic display or printer, thereby increasing the apparent image quality. Means for deriving a plurality of neighboring pixels of the video signal, and means for determining pixel modification in response thereto, are also shown. Particular embodiments relating to increasing the apparent temporal and spatial resolution of raster scanned television devices are shown.

Claims

1. Apparatus for improving the apparent resolution of an image displayed by a display device, the image made up of a number of image elements, including in combination, a neighboring pixel means responsive to a signal which carries said image to provide a plurality of image elements, and a fill calculator means responsive to said plurality of image elements to generate a fill signal indicating where said display device may alter voids between said image elements improving the apparent resolution of the image without requiring an increase in the number of image elements originally making up the image.

2. Apparatus as claimed in claim 1 wherein said signal is a video signal, and said neighboring pixel means operates to delay said video signal thereby providing said plurality of image elements.

3. Apparatus as claimed in claim 2 wherein said fill calculator means operates to compare a first image element of said plurality of image elements to one or more neighboring elements of said plurality of image elements to determine if a void between any of said neighboring elements is to be altered.

4. Apparatus as claimed in claim 3 wherein said fill calculator means operates to compare said first image element to a plurality of said neighboring elements.

5. Apparatus as claimed in claim 3 wherein said fill calculator means operates to compare said first image element to a plurality of said neighboring elements to dertermine the relative differences between said first image element and each of said plurality of said neighboring elements, said fill calculator means further operating to rank said plurality of said neighboring elements, according to their respective relative differences.

6. Apparatus as in claim 1 wherein said fill signal is responsive to the difference between a first image element and a neighboring image element of said plurality of image elements.

7. Apparatus as in claim 6 wherein said fill signal has a value, which value is responsive to said difference.

14. The device or apparatus of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or 13 said device or apparatus including a scanning beam wherein the scanning of said beam is altered in response to some or all of said image elements of said signal carrying said image in order that areas of said displayed image, which would otherwise not be scanned, may be caused to be scanned in order to increase the apparent quality of said displayed image.

8. Apparatus for improving the image quality of a displayed image, the image made up of a number of image elements carried by a signal, the apparatus including in combination a neighboring pixel means responsive to the signal carrying said displayed image to provide a plurality of image elements including a central pixel and a plurality of neighboring pixels and a fill calculator means responsive to said central and neighboring pixels to generate a fill signal indicating voids in said displayed image which may be filled, which said displayed image is displayed by a display device thereby improving the apparent resolution of the image without requiring an increase in the number of image elements originally making up the image.

9. Apparatus as claimed in claim 8 wherein said signal is a video signal and said neighboring pixel means operates to delay said video signal thereby providing said neighboring pixels, and said fill calculator means operates according to logical equations to generate said fill signal.

10. Apparatus as claimed in claim 8 wherein said fill calculator means operates to compare said central pixel to said neighboring pixels to determine relative differences thereof, and to rank at least some pixels from the group of said pixels which are compared according to their respective relative differences.

11. An improvement for a scan device for displaying an image carried on a video signal, the image made up of a number of image elements, the improvement including in combination a neighboring pixel means responsive to said video signal to provide image elements including a central pixel and at least one neighboring pixel, a fill calculator means responsive to said central and neighboring pixels to determine the location of areas of said image being void between image elements and generating a fill signal operative to cause said scan device to perform spatial altering of the display of said central pixel to fill the voids thereby improving the apparent resolution of the image without requiring an increase in the number of image elements originally making up the image.

12. The improvement of claim 11 wherein said fill signal causes the scanning of said scanned device to deviate from the normal scanning location for said central pixel thereby causing said central pixel to be displayed in said fill areas of said image.

13. The improvement of claim 12 wherein said scanned device contains a CRT and said fill signal causes a position of the electron beam to be spatially modulated on the face of said CRT thereby causing said central pixel to be displayed in a larger than normal area.

15. A method of improving the quality of an image which may be displayed on an image display device, the image made up of a number of image elements, including the step of selecting a plurality of pixels of said image, the step of comparing a first of said selected pixels to at least a second of said selected pixels to select voids of said image to be altered and including the further step of altering voids in said image in response to said comparing step thereby improving the apparent resolution of the image without requiring an increase in the number of image elements originally making up the image.

16. The method of claim 15 wherein said altering step includes filling said voids with all or a portion of a pixel.

17. The method of claim 15 wherein said altering step includes filling said voids with a combination of a plurality of pixels.

18. The method of claim 17 wherein said combination of a plurality of pixels may include all or none of said compared pixels.

19. A method of modifying a video signal representing an image, the image made up of a number of image elements, said modification enhancing the display of said image by a display apparatus which display includes scanning a raster, said video signal including lines of video corresponding to raster lines with said lines of video including elements, said method including the steps of:

storing in temporary storage means a known number of said elements from a known number of said lines of video to form a set of said elements said set of elements including elements having binary illumination conditions such as in a computer display;

identifying a central element from the central area of said set of elements which central element is one of said set of elements;

generating a modification signal in response to said set of elements said modification signal responsive to said central element and other said elements which are part of said set of elements to indicate when said central element is in a binary illumination state and is adjacent to one or more elements in another binary illumination state; and

modifying said central element before the display thereof in response to said modification signal to change the value of said central element to a value being in one or the other binary illumination state elements thereby improving the apparent resolution of the image without requiring an increase in the number of image elements originally making up the image.

21. A method as claimed in claim 19 or 20, wherein the step of modifying includes changing the size of said central element to more closely match ones of said elements of said set of elements.

22. A method as claimed in claim 19 or 20, wherein the step of modifying includes reducing the size of said central element to display a portion thereof.

23. A method as claimed in claim 19 or 20, wherein the step of modifying includes changing the relative position of the display of said central element by altering the scanning thereof in response to said modification signal.

24. A method as claimed in claim 19 or 20, wherein the step of modifying includes changing the value of said central element to more closely match the values of some of said elements of said set of elements.

25. A method as claimed in claim 19 or 20, wherein the value of said central element is changed to a value between the values of two of said elements of said set.

20. A method of enhancing the display of an image by a display apparatus, the image made up of a number of image elements, which display includes scanning a raster, said raster including raster lines, said raster lines including elements which include elements having binary illumination conditions such as in a computer display, said method including the steps of:

storing in temporary storage means a known number of said elements of a known number of said raster lines to form a set of said elements;

generating a central element representative of the central area of said set of elements;

generating a modification signal in response to said set of elements; and

modifying the display of said central element in response to said modification signal to improve its spatial resolution relationship with its neighboring elements thereby improving the apparent resolution of the image without requiring an increase in the number of image elements originally making up the image.

26. A method for improving the apparent resolution of an image, said method comprising examining a central element and one or more neighboring elements in order to determine the relationship therebetween,

said central element and said neighboring element having blank areas therebetween containing no substantive information, altering the size or shape of said central element in order to provide information for the blank areas between said central and neighboring elements, thus improving the apparent resolution of the image.

27. The method of claim 26 wherein the change in central element size or shape is accompanied by increasing the brightness of the beam creating such central element.

28. The method of claim 26 wherein the change in size or shape of said central element is accomplished by filling or dithering the scan that creates said central element at the appropriate time.

29. The method of claim 26 characterized in that the analysis of the relationship between the central element and said neighboring element develops a fill signal, which said central element having its size or shape modified in accord with such fill signal.

30. The method of claim 29 wherein said fill signal is added to the signal for said central element such that said central element is illuminated in response to both said central element signal and said fill signal.

31. The method of claim 26 wherein the image is a computer character displayable on a CRT.

32. An apparatus for improving the apparent resolution of an image having a central element and one or more neighboring elements, there being blank areas therebetween,

said apparatus including a means for determining the relationship between a central element and a neighboring element, and changing the size or shape of at least one element in response to said relationship so as to fill in the blank area between such central element and neighboring element.

33. The apparatus of claim 32 wherein said relationship between said central element and said neighboring element is utilized to develop a fill signal, with said at least one element being modified in accord to such fill signal.

34. The apparatus of claim 32 wherein the size or shape of said at least one element is altered by modifying the signal illumination for such element.

35. The apparatus of claim 34 characterized in that signal illumination is modified by adding the fill signal to the signal of said at least one element.

36. The apparatus of claim 34 wherein the elements are generated by a scan and wherein the signal illumination signal is modified by filling or dithering the scan at the appropriate time so as to alter the size or shape of said at least one element.

37. The apparatus of claim 36 characterized in that said at least one element includes the central element.

38. The apparatus of claim 37 characterized in that said at least one element includes a neighboring element.

39. The apparatus of claim 32 wherein such image is a computerized character display.

40. An apparatus for improving the apparent resolution of a scanned image having a central and neighboring elements developed by a signal, there being blank areas between such elements, said apparatus comprising a spatial scan modulator, means to input the signal for the image into said spatial scan modulator,

said spatial scan modulator including a neighboring pixel means and a pixel fill calculator means, said neighboring pixel means providing a central element and a neighboring element to said pixel fill calculator means by delaying one or more of the elements of the image, said neighboring pixel means in addition delaying the input signal in order to make up for processing delays,

said pixel fill calculator means comparing the central element to a neighboring element in order to develop a fill signal including a vertical fill signal and a horizontal fill signal,

changing the size or shape of such central element and neighboring element in vertical and horizontal directions in response to said horizontal fill signal and vertical fill signal respectively so as to fill in the blank areas between such elements thus improving the apparent resolution of the image.

41. An apparatus for improving the apparent resolution of an image, said image being generated by elements, said apparatus comprising a neighboring pixel means, said neighboring pixel means developing a central and neighboring elements,

a pixel fill calculator, said pixel fill calculator including a rank logic means and a fill logic means, means to pass said central and neighboring elements from said neighboring pixel means to said rank logic means, said rank logic means comparing said neighboring elements to determine the differences between said central and said neighboring elements and to rank said neighboring elements according to their similarity to said central element, said rank logic means providing the ranking of the neighboring elements to said fill logic means,

and said fill logic means generating elements between the central element and the neighboring element by modulating such central and neighboring elements respectively in accord with the relative ranking of such neighboring elements in respect to the central element.