Image file processing method, system and storage medium

Patent metadata

Field	Value
Publication number	US-11012716-B2
Application number	US-201916374314-A
Country	US
Kind code	B2
Filing date	Apr 3, 2019
Priority date	Apr 8, 2017
Publication date	May 18, 2021
Grant date	May 18, 2021

Abstract

A picture file processing method, apparatus, and computer readable medium are provided. The method includes parsing a picture file, to obtain a picture header information data segment, first stream data, and second stream data of a first image thereof. The first stream data of the first image is decoded to generate red-green-blue (RGB) data of the first image. The second stream data of the first image is decoded to generate Alpha data of the first image. Red-green-blue-alpha (RGBA) data corresponding to the first image are generated according to the RGB data and the Alpha data.

First claim

What is claimed is:

1. A method executed by at least one processor, the method comprising:
parsing a picture file, to obtain a picture header information data segment, first stream data, and second stream data of a first image thereof, the picture header information data segment including image feature information including an alpha channel flag that indicates whether the picture file includes alpha channel data;
based on the alpha channel flag indicating the picture file includes alpha channel data, parsing the picture file to obtain an image frame header information data segment and a transparent channel frame header information data segment;
decoding the first stream data of the first image according to information included in the image frame header information data segment using a first video decoding mode, to generate red-green-blue (RGB) data of the first image;
decoding the second stream data of the first image according to information included in the transparent channel frame header information data segment using a second video decoding mode, to generate Alpha data of the first image; and
generating red-green-blue-alpha (RGBA) data corresponding to the first image according to the RGB data and the Alpha data of the first image,
wherein the first video decoding mode comprises at least an I-frame decoding mode, and the second video decoding mode comprises the I-frame decoding mode and/or a P-frame decoding mode.

2. The method according to claim 1 , wherein the decoding the first stream data comprises:
decoding the first stream data to generate first brightness and chrominance (YUV) data of the first image, wherein the first YUV data is first color encoding data generated according to the RGB data of the first image; and
converting the first YUV data into the RGB data of the first image.

3. The method according to claim 1 , wherein the decoding the second stream data comprises:
decoding the second stream data to generate second YUV data of the first image, wherein the second YUV data is second color encoding data generated according to transparency data of the first image; and
converting the second YUV data into the Alpha data of the first image.

4. The method according to claim 3 , wherein the converting the second YUV data comprises:
setting a Y component in the second YUV data to the Alpha data of the first image, and discarding UV components in the second YUV data; or
setting the Alpha data of the first image to the Y component in the second YUV data, and setting UV components in the second YUV data to be preset data.

5. The method according to claim 1 , further comprising:
updating a value of k in response to the picture file being a picture file in a dynamic format and the first image being an image corresponding to a kth frame in the picture file of the dynamic format, to obtain, from a stream data segment of the picture file, third stream data and fourth stream data that are generated from a second image corresponding to an updated kth frame in the picture file;
decoding the third stream data to generate RGB data of the second image;
decoding the fourth stream data to generate Alpha data of the second image; and
generating RGBA data corresponding to the second image according to the RGB data and the Alpha data of the second image.

6. The method according to claim 5 , wherein the updating the value of k comprises adding 1 to the value of k, and
wherein
after the generating RGBA data corresponding to the second image according to the RGB data and the Alpha data of the second image, the method further comprises:
determining whether the image that corresponds to the current kth frame is a last frame in the picture file of the dynamic format, and
in response to determining that the first image is the last frame, completing decoding on the picture file of the dynamic format, and
in response to determining that the image is not the last frame, updating the value of k again, wherein k is a positive integer greater than or equal to 1.

7. The method according to claim 1 , wherein the picture header information data segment further comprises image sequence header data, image supplement data and image user data, wherein the image sequence header data is configured to identify the picture file, the image supplement data is configured to describe exchangeable image file format (EXIF) information of the picture file, and the image user data comprises information of an image user data start code and a user data length.

8. The method according to claim 7 , wherein the image sequence header data comprises an image identifier, a codec ID, and a version ID;
the image identifier indicates a type of the picture file, and the codec ID indicates an identifier of a decoding standard decoding the picture file; and
the version ID indicates a profile of the decoding standard.

9. The method according to claim 1 , wherein the image feature information further comprises an image feature start code, an image feature data length, a dynamic picture flag, a value of YUV format, a lossless flag, a YUV limit range flag, an information of reserved bits, a width of the picture file, a height of the picture file.

10. The method according to claim 1 ,
wherein the image frame header information data segment indicates one of the image feature information of each image of the picture file, and the image frame header information data segment comprises an image frame start code, an information of image frame stream length, and delay time information related to the picture file when the picture file is in a dynamic format; and
the transparent channel frame header information data segment indicates another image feature information in the second stream data, and the transparent channel frame header information data segment comprises an alpha channel start code, and information of an alpha frame stream length,
wherein the second stream data of the first image is decoded based on the alpha channel start code and the alpha frame stream length to generate Alpha data of the first image.

11. An apparatus comprising:
at least one memory configured to store computer program code; and
at least one processor configured to access the at least one memory and operate according to the computer program code, the computer program code comprising:
first obtaining code configured to cause at least one of the at least one processor to obtain a picture header information data segment, first stream data, and second stream data of a first image by parsing a picture file, the picture header information data segment including image feature information including an alpha channel flag that indicates whether the picture file includes alpha channel data;
second obtaining code configured to cause at least one of the at least one processor to, based on the alpha channel flag indicating the picture file includes alpha channel data, obtain an image frame header information data segment and a transparent channel frame header information data segment by parsing the picture file;
first decoding code configured to cause at least one of the at least one processor to decode the first stream data of the first image according to information included in the image frame header information data segment using a first video decoding mode, to generate red-green-blue (RGB) data of the first image;
second decoding code configured to cause at least one of the at least one processor to decode the second stream data of the first image according to information included in the transparent channel frame header information data segment using a second video decoding mode, to generate Alpha data of the first image; and
first generation code configu

Assignees

• Tencent Tech Shenzhen Co Ltd
• Tencent Tech Shenzhen Company Ltd

Inventors

• Wang Shitao
• Liu Xiaoyu
• Chen Jiajun
• Huang Xiaozheng
• Ding Piao
• Liu Haijun
• Luo Binji
• Chen Xinxing

Classifications

• H04N19/186

  the unit being a colour or a chrominance component · CPC title

• H04N21/440236

  by media transcoding, e.g. video is transformed into a slideshow of still pictures, audio is converted into text · CPC title

• H04N21/8146

  involving graphical data, e.g. 3D object, 2D graphics · CPC title

• H04N19/44

  Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder · CPC title

• H04N21/234336

  by media transcoding, e.g. video is transformed into a slideshow of still pictures or audio is converted into text · CPC title