Display processor with color matrixing circuitry and two map memories storing chrominance-only data

• US 4,719,503 A
• Filed: 10/14/1986
• Issued: 01/12/1988
• Est. Priority Date: 06/18/1986
• Status: Expired due to Term

• Current Assignee: Intel Corporation, RCA Corporation
• Original Assignee: RCA Corporation
• Inventors: Craver, Thomas R., Arbeiter, James H.
• Primary Examiner(s): Shepperd, John W.
• Application Number:
  US06/918,565
• Time in Patent Office: 455 Days
• Field of Search: 340/703, 358/12, 358/13, 358/21 R
• US Class Current: 348/717
• CPC Class Codes: G09G 1/285 Interfacing with colour displays, e.g. TV receiver

Abstract

A display processor using first and second chrominance map memories for storing values of first and second color-difference signals, each normalized respective to luminance signal. An image memory supplies, at pixel scan rate, data used to provide read-addresses to said first and second chrominance map memories and data used to describe the luminance signal. The first and second chrominance map memory read-outs are each multiplied by the luminance signal of appropriate spatial bandwidth to generate descriptions of the first and second color-difference signals i non-normalized form. These first and second color-difference signals and a full-spatial-bandwidth luminance signal are supplied to color matrixing circuitry. The color matrixing circuitry responds to these signals to provide red, green and blue drive signals to display apparatus. The display apparatus may comprise video amplifiers for the drive signals and a color kinescope, by way of example.

Claims

1. A display processor for color video signals comprising:

first and second map memories addressed in parallel, for storing values of first and second chrominance-only signals respectively, each normalized respective to luminance;

means for synchronously providing during display line trace intervals first and second streams of data, the first stream of data being descriptive of display luminosity fully sampled at a given spatial density, and the second stream of data being descriptive of display chromaticity fully sampled at said given spatial density and being applied as read addresses to said first and second map memories;

means responsive to said first stream of data for supplying a luminance-only signal;

means responsive to the read-outs of said first and second map memories for supplying first and second color-difference signals normalized respective to luminance;

means for multiplying, by said luminance signal, each of said first and second color-difference signals normalized respective to luminance, thereby to generate first and second color-difference signals; and

color matrixing circuitry for linearly combining these said first and second color-difference signals with said luminance-only signal for generating video drive signals in each of three primary colors.

2. A display processor as set forth in claim 1 including:

means for re-writing at least portions of said first and second map memories during display line retrace intervals.

3. A display processor as set forth in claim 1 wherein said means responsive to said first stream of data for supplying a luminance signal includes:

a third map memory responsive to said first stream of data being applied as its read address for storing values of said luminance-only signal.

4. A display processor as set forth in claim 3 wherein said means for multiplying comprises:

first and second analog multipliers; and

wherein said means responsive to said first stream of data for supplying a luminance signal includes;

first digital-to-analog converting means for converting digital values of said luminance-only signal supplied from said third map memory to luminance-only signal in analog form, which is supplied to said color matrixing circuitry and applied to said first and second analog multipliers as their multiplier signals; and

wherein said means responsive to the read-outs of said first and second map memories for supplying first and second color-difference signals normalized respective to luminance includes;

second digital-to-analog converting means for converting the read-out of said first map memory to said first color-difference signal normalized respective to luminance, in analog form, for application to said first analog multiplier as its multiplicand signal, causing said first analog multiplier to supply said first color-difference signal in analog form as its output product applied to said color matrixing circuitry; and

wherein said means responsive to the read-outs of said first and second map memories for supplying first and second color-difference signals normalized respective to luminance includes;

third digital-to-analog converting means for converting the read-out of said second map memory to said second color-difference signal normalized respective to luminance, in analog form, for application to said second analog multiplier as its multiplicand signal, causing said second analog multiplier to supply said second color-difference signal in analog form as its output product applied to said color matrixing circuitry.

5. A display processor as set forth in claim 1 wherein said means for multiplying comprises:

first and second analog multipliers; and

wherein said means responsive to said first stream of data for supplying a luminance signal includes;

first digital-to-analog converting means for converting digital values of said first stream of data to luminance-only signal in analog form, which is supplied to said color matrixing circuitry and applied to said first and second analog multipliers as their multiplier signals; and

wherein said means responsive to the read-outs of said first and second map memories for supplying first and second color-difference signals normalized respective to luminance includes;

second digital-to-analog converting means for converting the read-out of said first map memory to said first color-difference signal normalized respective to luminance, in analog form, for application to said first analog multiplier as its multiplicand signal, causing said first analog multiplier to supply said first color-difference signal in analog form as its output product applied to said color matrixing circuitry; and

wherein said means responsive to the read-outs of said first and second map memories for supplying first and second color-difference signals normalized respective to luminance includes;

third digital-to-analog converting means for converting the read-out of said second map memory to said second color-difference signal normalized respective to luminance, in analog form, for application to said second analog multiplier as its multiplicand signal, causing said second analog multiplier to supply said second color-difference signal in analog form as its output product applied to said color matrixing circuitry.

6. A display processor for color video signals comprising:

first and second map memories addressed in parallel, for storing values of first and second chrominance-only signals respectively, each normalized respective to luminance;

means for providing first and second streams of data, the first stream of data being descriptive of display luminosity fully sampled at a given spatial density, and the second stream of data being descriptive of display chromaticity subsampled at said given spatial density and being applied as read addresses to said first and second map memories;

means responsive to said first stream of data for supplying a full-spatial-bandwidth luminance-only signal;

means responsive to the read-outs of said first and second map memories for sampling first and second color-difference signals normalized respective to luminance and restricted to less than full spatial bandwidth as compared to said full-spatial-bandwidth luminance-only signal;

means for low-pass spatially filtering said luminance-only signal to the same spatial bandwidth as said color-difference signals normalized respective to luminance, for generating a multiplier signal;

differential delay means for temporally aligning said full-spatial bandwidth luminance signal with said multiplier signal and said color-difference signals normalized respective to luminance;

means for multiplying by said multiplier signal each of said first and second color-difference signals normalized respective to luminance, thereby to generate first and second color-difference signals; and

means for linearly combining these said first and second color-difference signals with said temporally aligned full-spatial-bandwidth luminance-only signal for generating video drive signals in each of three primary colors.

7. A display processor as set forth in claim 6 including:

means for re-writing at least portions of said first and second map memories during display line retrace intervals.

8. A display processor as set forth in claim 6 wherein said means responsive to said second stream of data for supplying a luminance signal includes:

a third map memory responsive to said first stream of data being applied as its read address for storing values of said luminance-only signal.

9. A display processor as set forth in claim 8 wherein said means for multiplying comprises:

first and second analog multipliers;

wherein said means responsive to said first stream of data for supplying a luminance signal includes;

first digital-to-analog converting means for converting digital values of said luminance-only signal supplied from said third map memory to luminance-only signal in analog form, which is supplied to said color matrixing circuitry and applied to said first and second analog multipliers as their multiplier signals; and

wherein said means responsive to the read-outs of said first and second map memories for supplying first and second color-difference signals normalized respective to luminance includes;

second digital-to-analog converting means for converting the read-out of said first map memory to said first color-difference signal normalized respective to luminance, in analog form, for application to said first analog multiplier as its multiplicand signal, causing said first analog multiplier to supply said first color-difference signal in analog form as its output product applied to said color matrixing circuitry; and

wherein said means responsive to the read-outs of said first and second map memories for supplying first and second color-difference signals normalized respective to luminance includes;

third digital-to-analog converting means for converting the read-out of said second map memory to said second color-difference signal normalized respective to luminance, in analog form, for application to said second analog multiplier as its multiplicand signal, causing said second analog multiplier to supply said second color-difference signal in analog form as its output product applied to said color matrixing circuitry.

10. A display processor as set forth in claim 6 wherein said means for multiplying comprises:

first and second analog multipliers;

wherein said means responsive to said first stream of data for supplying a luminance signal includes;

first digital-to-analog converting means for converting digital values of said first stream of data to luminance-only signal in analog form, which is supplied to said color matrixing circuitry and applied to said first and second analog multipliers as their multiplier signals; and

wherein said means responsive to the read-outs of said first and second map memories for supplying first and second color-difference signals normalized respective to luminance includes;

second digital-to-analog converting means for converting the read-out of said first map memory to said first color-difference signal normalized respective to luminance, in analog form, for application to said first analog multiplier as its multiplicand signal, causing said first analog multiplier to supply said first color-difference signal in analog form as its output product applied to said color matrixing circuitry; and

wherein said means responsive to the read-outs of said first and second map memories for supplying first and second color-difference signals normalized respective to luminance includes;

third digital-to-analog converting means for converting the read-out of said second map memory to said second color-difference signal normalized respective to luminance, in analog form, for application to said second analog multiplier as its multiplicand signal, causing said second analog multiplier to supply said second color-difference signal in analog form as its output product applied to said color matrixing circuitry.

11. Apparatus for generating signals descriptive of color imagery comprising:

means for supplying a relatively wideband luminance signal;

means for supplying first and second color difference signals having narrower spatial bandwidths than said luminance signal, in all directions;

means for filtering said luminance signal to the same spatial bandwidth as each of said color difference signals;

means for dividing each of said color-difference signals by luminance signal filtered to the same narrower spatial bandwidth as its own; and

means responsive to the resulting quotients for generating chrominance-descriptive codes to accompany said relatively wideband luminance signal, as said signals descriptive of color imagery.