# US 2019/0172428 A1 · Method and system for detecting video scan type > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0172428 A1 - Document ID: US20190172428A1 - Status: Published application - Kind: A1 - Application number: 16/163,650 - Filed: 2018-10-18 - Published: 2019-06-06 - Earliest claimed: 2017-12-06 - Assignees: Realtek Semiconductor Corp. - Applicants: Realtek Semiconductor Corp. - Inventors: MING-TA LIN - Web page: https://patentgrep.com/patent/US20190172428A1 ## CPC - G09G 5/42: characterised by the display of patterns using a display memory without fixed position correspondence between the display memory contents and the display position on the screen - G09G 5/36: characterised by the display of a graphic pattern, e.g. using an all-points-addressable [APA] memory - H04N 7/012: {Conversion between an interlaced and a progressive signal (for graphics images G09G2310/0229)} - G09G 2310/0202: Addressing of scan or signal lines - G09G 2310/0224: Details of interlacing - G09G 2310/0229: De-interlacing - G09G 2320/103: Detection of image changes, e.g. determination of an index representative of the image change - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract The disclosure is related to a method and a system for detecting a video scan type. In the method, a first frame and a second frame are firstly extracted from a video. The scan lines of each frame can be divided into a top field and a bottom field. A first zipper index of the combination of the top field of the first frame and the bottom field of the second frame is obtained. Further, a second zipper index of the combination of the bottom field of the first frame and the top field of the second frame is also obtained. A zipper index difference between the first zipper index and the second zipper index is calculated and is provided to determine the video scan type as an interlaced-scan video or a progressive-scan video. ## Claims ### Claim 1 A method for detecting a video scan type, comprising: obtaining pixel information relating to a first frame and a second frame extracted from a video; dividing scan lines of each of the first frame and the second frame into a top field and a bottom field; calculating a first zipper index from a combination of the top field of the first frame and the bottom field of the second frame; calculating the a second zipper index from a combination of the bottom field of the first frame and the top field of the second frame; calculating a zipper index difference between the first zipper index and the second zipper index; according to the zipper index difference, determining a video scan type of the video; wherein, the video is an interlaced-scan video if the zipper index difference is larger than a predetermined threshold, and the video is a progressive-scan video if the zipper index difference is not larger than the predetermined threshold. ### Claim 2 (depends on 1) The method as recited in claim 1, wherein when the video is determined as the interlaced-scan video, a field order of the interlaced-scan video is determined by comparing the first zipper index with the second zipper index; wherein the interlaced-scan video is bottom field display first if the second zipper index is larger than the first zipper index, and the interlaced-scan video is top field display first if the first zipper index is larger than the second zipper index. ### Claim 3 (depends on 1) The method as recited in claim 1, further comprising performing a horizontal low-pass filtering on the pixel information of the video. ### Claim 4 (depends on 1) The method as recited in claim 1, wherein in the step of calculating the zipper index, a zipper value algorithm is used to calculate a zipper value of at least one pixel and obtain the zipper index of the frame. ### Claim 5 (depends on 4) The method as recited in claim 4, wherein the zipper value algorithm is: Ix=Y(x,y)−Y(x−1,y) Iy=Y(x,y)−Y(x,y−1) s=|Iy|−|Ix| If s≤0; k=0 If s>0; k=s wherein, the positions of the pixels are marked as (x,y), (x−1,y), (x,y−1) and (x−1,y−1); Y indicates a luminance within a YUV color space; Ix indicates a luminance difference in an X direction; Iy indicates a luminance difference in a Y direction; s is a difference between an absolute value of Ix and an absolute value of Iy; wherein the zipper value k is 0 if s is smaller than or equal to 0, and the zipper value k equals s if s is larger than 0. ### Claim 6 (depends on 5) The method as recited in claim 5, wherein, a higher zipper value is given to the pixel if the zipper value of the pixel is larger than a first threshold. ### Claim 7 (depends on 6) The method as recited in claim 6, wherein a lower zipper index is given to the pixel if the zipper value of the pixel is not larger than the first threshold but larger than a second threshold, and no zipper index is given if the zipper value of the pixel is smaller than both the first threshold and the second threshold. ### Claim 8 (depends on 7) The method as recited in claim 7, wherein when the video is determined as the interlaced-scan video, a field order of the interlaced-scan video is determined by comparing the first zipper index with the second zipper index; wherein the interlaced-scan video is bottom field display first if the second zipper index is larger than the first zipper index, and the interlaced-scan video is top field display first if the first zipper index is larger than the second zipper index. ### Claim 9 (depends on 8) The method as recited in claim 8, wherein when the video scan type of the video is determined, the video is played according to the determined video scan type. ### Claim 10 A system for detecting a video scan type for a player, comprising: a memory and a processor, the processor performing a method for detecting the video scan type, including: obtaining pixel information relating to a first frame and a second frame extracted from a video; dividing scan lines of each of the first frame and the second frame into a top field and a bottom field; calculating a first zipper index from a combination of the top field of the first frame and the bottom field of the second frame; calculating the a second zipper index from a combination of the bottom field of the first frame and the top field of the second frame; calculating a zipper index difference between the first zipper index and the second zipper index; according to the zipper index difference, determining a video scan type of the video; wherein, the video is an interlaced-scan video if the zipper index difference is larger than a predetermined threshold, the video is a progressive-scan video if the zipper index difference is not larger than the predetermined threshold. ### Claim 11 (depends on 10) The system as recited in claim 10, wherein when the video is determined as the interlaced-scan video, a field order of the interlaced-scan video is determined by comparing the first zipper index with the second zipper index; wherein the interlaced-scan video is bottom field display first if the second zipper index is larger than the first zipper index, and the interlaced-scan video is top field display first if the first zipper index is larger than the second zipper index. ### Claim 12 (depends on 10) The system as recited in claim 10, further comprising performing a horizontal low-pass filtering on the pixel information of the video. ### Claim 13 (depends on 10) The system as recited in claim 10, wherein the determined video scan type is stored in the memory, and the determined field order is also stored in the memory if the video is determined as the interlaced-scan video. ### Claim 14 (depends on 10) The system as recited in claim 10, wherein in the step of calculating the zipper index, a zipper value algorithm is used to calculate a zipper value of at least one pixel and obtain the zipper index of the frame. ### Claim 15 (depends on 14) The system as recited in claim 14, wherein the zipper value algorithm is: Ix=Y(x,y)−Y(x−1,y) Iy=Y(x,y)−Y(x,y−1) s=|Iy|−|Ix| If s≤0; k=0 If s>0; k=s wherein the positions of the pixels are marked as (x,y), (x−1,y), (x,y−1) and (x−1,y−1); Y indicates a luminance within a YUV color space; Ix indicates a luminance difference in an X direction; Iy indicates a luminance difference in a Y direction; s is a difference between an absolute value of Ix and an absolute value of Iy; wherein the zipper value k is 0 if s is smaller than or equal to 0; the zipper value k equals s if s is larger than 0. ### Claim 16 (depends on 15) The system as recited in claim 15, wherein, a higher zipper value is given to the pixel if the zipper value of the pixel is larger than a first threshold. ### Claim 17 (depends on 16) The system as recited in claim 16, wherein a lower zipper index is given to the pixel if the zipper value of the pixel is not larger than the first threshold and larger than a second threshold, and no zipper index is given if the zipper value of the pixel is smaller than both the first threshold and the second threshold. ### Claim 18 (depends on 17) The system as recited in claim 17, wherein, when the video is determined as the interlaced-scan video, a field order of the interlaced-scan video is determined by comparing the first zipper index with the second zipper index; wherein, the interlaced-scan video is bottom field display first if the second zipper index is larger than the first zipper index, and the interlaced-scan video is top field display first if the first zipper index is larger than the second zipper index. ### Claim 19 (depends on 18) The system as recited in claim 18, wherein when the video scan type of the video is determined, the video is played according to the determined video scan type. ### Claim 20 (depends on 19) The system as recited in claim 19, wherein the determined video scan type is stored in the memory, and the determined field order is also stored in the memory if the video is determined as the interlaced-scan video.