Method for detecting video frame types with median filtering

• US 20040207752A1
• Filed: 04/15/2003
• Published: 10/21/2004
• Est. Priority Date: 04/15/2003
• Status: Active Grant

• Current Assignee: Silicon Integrated Systems Corporation (Silicon Integrated Systems Corporation Taiwan)
• Original Assignee: Silicon Integrated Systems Corporation (Silicon Integrated Systems Corporation Taiwan)
• Inventors: Lin, Wen-Kuo, Yan, Jong-Ho
• Granted Patent: US 7,215,380 B2
• Time in Patent Office: Days
• US Class Current: 348/449
• CPC Class Codes: H04N 7/0112 one of the standards corresponding to a cinematograph film standard
• CPC Class Codes: H04N 7/012 Conversion between an interlaced and a progressive signal for graphics images G09G2310/0229

Abstract

The invention relates to a method for detecting video frame types with median filtering, which proceeds a denoising step after caculating the comb factor of each pixel, to avoid incorrect judgment of the frame type resulting from excessive field difference and improve detection accuracy.

Claims

1. A method for detecting video frame types with median filtering, comprising steps of:

inputting pixels in a frame into a processor in order;

calculating comb factor values of the pixels in the frame with a function;

proceeding median filtering step to determine the comb factor value of each pixel;

adding 1 to a counter if the pixel is comb factor;

keeping the counter unchanged if the pixel is not comb factor;

determining frame types according to the counter value and counter threshold value; and

ending the detection flow.

2. The method for detecting frame types with median filtering according to claim 1, wherein the step of with median filtering includes:

comparing the comb factor value with the comb factor threshold value;

setting Combmap1 at the pixel location to be 1 if it is more than the comb factor threshold value;

setting Combmap1 at the pixel location to be zero if it is less than the comb factor threshold value, and

calculating the counts of comb map 1 of each pixel.

3. The method for detecting frame types with median filtering according to claim 2, more comprising:

comparing the counts with a majority threshold;

adding 1 to the counter if it is more than the majority threshold; and

keeping the counter unchanged if it is less than the majority threshold.

4. The method for detecting frame types with median filtering according to claim 2, more comprising:

comparing the counts with a majority threshold;

setting Combmap2 at the pixel location to be 1, if it is more than the majority threshold;

;

setting Combmap2 at the pixel location to be zero if it is less than the majority threshold;

determining whether each compmap2 is 1;

adding 1 to the counter if the Combmap2 is 1; and

keeping the counter unchanged the Combmap2 is not 1.

5. The method for detecting frame types with median filtering according to claim 1, wherein the step of detecting frame types with median filtering includes determining a frame type according to the counter value, and it is a progressive frame if the counter value is smaller than the counter threshold value, otherwise, it is an interlaced frame.

6. The method of detecting frame types with median filtering, comprising steps of:

inputting all pixels of a frame into a processor in order;

calculating the comb factor value of each pixel according to a function;

calculating the value of Combmap1 of each pixel;

calculating the counts of each pixel according to the value of the Combmap1 of each pixel,and comparing the counts with a majority threshold;

setting the corresponding Combmap2 at the pixel location to be 1 if it is more than the majority threshold;

setting the corresponding Combmap2 at the pixel location to be zero if it is less than the majority threshold;

determining if each Combmap2 is 1;

adding 1 to the counter if the Combmap2 is 1;

keeping the counter unchanged if the Combmap2 is not 1;

determining the frame type according to the counter value and counter threshold value; and

ending the detection flow.

7. The method for detecting frame types with median filtering according to claim 6, wherein the steps of calculating the value of Combmap1 of each pixel, comprising the step of comparing the comb factor value with a comb factor threshold value;

Setting the value of the corresponding comb map to be 1 if it is more than the threshold value;

setting the corresponding value of Combmap1 to be zero if it is less than the threshold value.