Pixel data processing for spatial light modulator having staggered pixels

• US 5,530,482 A
• Filed: 03/21/1995
• Issued: 06/25/1996
• Est. Priority Date: 03/21/1995
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Gove, Robert J., Markandey, Vishal
• Primary Examiner(s): Kostak, Victor R.
• Application Number:
  US08/407,938
• Time in Patent Office: 462 Days
• Field of Search: 348/770, 348/771, 348/441, 348/448, 348/581, 345/127, 345/204, 345/214
• US Class Current: 348/441
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: H04N 7/012 Conversion between an interlaced and a progressive signal for graphics images G09G2310/0229
• CPC Class Codes: H04N 9/30 using solid-state colour display devices

Abstract

Methods of processing pixel data for display on a spatial light modulator (SLM) (15) having staggered pixels. An analog image signal in interlaced field format is sampled to provide staggered pixel data in field format, where pixel values in odd lines are offset from pixel values in even lines. This staggered pixel data may be converted to progressive scan frame format using special calculations to accommodate the line-to-line offset of the pixels (FIGS. 2-6). Vertical scaling may also be performed, either before or after the data is converted to frame format (FIGS. 7 and 8).

Claims

1. A method of converting an analog input signal in interlaced field format to vertically scaled pixel data in frame format for display on a spatial light modulator (SLM) having staggered pixels, comprising the steps of:

sampling said input signal so as to provide pixel values in staggered pixel format;

interpolating said pixel values of each field to provide new lines in accordance with a scaling ratio; and

for each field of said sampled pixel values, providing a new line of new pixel values to be displayed between every existing line of said sampled pixel values.

2. The method of claim 1, wherein said providing step is performed by copying existing pixel values from an adjacent field.

3. The method of claim 1, wherein said providing step is performed by calculating new pixel values.

4. The method of claim 3, wherein said new pixel values are calculated by averaging pixel values on a line above or below said new line.

5. The method of claim 3, wherein said new pixel values are calculated by averaging nearest neighbor pixel values of each new pixel.

6. The method of claim 1, wherein said providing step includes the substep of detecting motion between said fields.

7. The method of claim 6, wherein said substep of detecting motion is performed by determining a motion value for each new pixel to be calculated.

8. A method of vertically scaling pixel data in frame format for display on a spatial light modulator (SLM) having staggered pixels, comprising the steps of:

using a first line of an input frame of pixel values as a first line of the scaled frame of pixel values;

calculating a second line of said scaled frame by interpolating values of adjacent lines of said input frame, said adjacent lines being said first line of said input frame and a second line of said input frame;

repeating said calculating step for each next line of said scaled frame, wherein the interpolated values are from lines of said input frame adjacent to said each next line;

if an even number of lines are between said first line and the last line of said scaled frame, horizontally interpolating values of the last line of said input frame to calculate values of said last line of said scaled frame; and

if an odd number of lines are between said first line and the last line of said scaled frame, using said last line of said input frame as the last line of said scaled frame.

9. The method of claim 8, wherein said calculating step is performed by calculating each new pixel value by interpolating a pixel value that is spatially aligned with said new pixel value and neighboring pixel values on one of said adjacent lines.

10. The method of claim 9, wherein said interpolating is weighted in favor of pixel values closest to said new pixel value.