Method and apparatus for representation of video and audio signals on a low-resolution display

• US 9,183,773 B2
• Filed: 03/14/2011
• Issued: 11/10/2015
• Est. Priority Date: 04/08/2002
• Status: Active Grant

• Current Assignee: 0960471 B.C. Unlimited Liability Company, Imagine Communications Limited (Gores Broadcast Holdings LLC)
• Original Assignee: Imagine Communications Limited (Gores Broadcast Holdings LLC)
• Inventors: Twarecki, Artur B., Batchelor, Mark
• Primary Examiner(s): Pham, Long D
• Application Number:
  US13/047,489
• Publication Number:
  US 20110221957A1
• Time in Patent Office: 1,702 Days
• Field of Search: 345/204, 345/691, 345/698, 348/441
• US Class Current: 1/1
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2340/145 related to small screens
• CPC Class Codes: G09G 3/001 using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: G09G 3/2029 the sub-frames having non-binary weights

Abstract

The method for the representation of video and audio signals on a low-resolution display panel, which includes the steps of: scaling the video or audio frame to fit the display panel, quantization of the video or audio signals to predetermined level values, temporal representation of video data by using the pulse density modulation, sending the signal pulses to the display panel. In further aspect the step of temporal representation contains the anti-flickering signal manipulation technique incorporating maximization of separation of the pulses during the pulse density modulation.

Claims

1. A method for modulation of a video signal for display on a low-resolution display, the method comprising:

scaling the video signal to fit the low-resolution display;

quantizing the video signal to predetermined level values;

generating a pulse density modulated representation of the scaled and quantized video signal;

altering the scaled and quantized video signal to result in an increased temporal distance between each two consecutive pulses in the pulse density modulated representation to decrease flickering; and

sending the pulse density modulated representation of the scaled and quantized video signal directly to a display buffer for output of the pulse density modulated representation of the scaled and quantized video signal to the low-resolution display.

2. The method of claim 1, wherein the low-resolution display is a gray-scale display.

3. The method of claim 1, wherein the generating further comprises generating a binary number for each luma in the scaled and quantized video signal, wherein each binary number is generated by incrementing a most significant bit of the binary number before incrementing a least significant bit of the binary number to reduce flickering at the low-resolution display.

4. The method of claim 1 further comprising:

receiving an audio data signal;

decimating the audio data signal;

quantizing the audio data signal;

transforming the decimated and quantized audio data signal into a logarithmic scale; and

sending the transformed audio data signal directly to the display buffer for output of the transformed audio data signal to the low-resolution display.

5. The method of claim 4, wherein the display buffer outputs one data signal to the low-resolution display, the data signal including the video signal representation and the transformed audio data signal.

6. The method of claim 4, further comprising displaying the video signal representation and the transformed audio data signal on the low-resolution display simultaneously.

7. The method of claim 1, wherein the pulse density modulated representation of the scaled and quantized video signal corresponds to brightness values of pixels of the low-resolution display for a given period of time.

8. The method of claim 7, wherein the brightness values for the pixels of the low-resolution display are set according to a number of pulses transmitted within the given period of time to the pixels as defined by the pulse density modulated representation of the scaled and quantized video signal.

9. The method of claim 8, wherein the pulse density modulated representation of the scaled and quantized video signal includes pulses distributed in the given time period to decrease flickering for each of the pixels of the low-resolution display.

10. The method of claim 1, further comprising adjusting each pixel of the low-resolution display to a corresponding brightness value based on the pulse density modulated representation of the scaled and quantized video signal to generate a gray-scaled version of the video signal on the low-resolution display.

11. A video signal modulator comprising:

a video processor configured to;

scale a video signal to fit a low-resolution display to generate a scale video signal; and

quantize the scaled video signal to decrease the number of bits representing digital values of the scaled video signal to generate a scaled and quantized video signal; and

a pulse density modulator configured to modulate the scaled and quantized video signal to generate a pulse density modulated video signal representation of the scaled and quantized video signal having an increased separation between consecutive pulses in the pulse density modulatedvideo signal to mitigate flickering;

an audieo signal transformer configured to transform and output a transformed audio data signal to the low-resolution display.

12. The video signal modulator of claim 11, wherein the low-resolution display is a gray-scale display.

13. A system comprising the video signal modulator of claim 11, the system further comprising:

a display buffer configured to;

receive and store the pulse density modulated video signal and the transformed audio data signal; and

output the pulse density modulated video signal and the transformed audio data signal to the low-resolution display.

14. A video and audio signal reproducer, the reproducer comprising:

a video signal modulator configured to scale a video signal to fit a low-resolution display, quantize the video signal to predetermined level values and generate a pulse density modulated representation of the scaled and quantized video signal having an increased temporal distance between each two consecutive pulses in the pulse density modulated representation to mitigate flickering;

an audio signal transformer configured to transform a the decimated and quantized audio data signal into a logarithmic scale and generate a transformed audio signal;

a display buffer configured to;

receive and store the pulse density modulated video signal and the transformed audio signal; and

output the pulse density modulated video signal representation and the transformed audio signal to the low-resolution display.

15. The reproducer of claim 14, wherein the audio signal transformer further comprises an audio processor configured to separate the transformed audio signal into left and right channel audio signals.

16. The reproducer of claim 15, wherein the left and right channel audio signals are displayed separately on the low-resolution display.