Two-layered image compression for text content
AssigneeGoogle Inc.
InventorsDi Chen, Balineedu Adsumilli, Debargha Mukherjee, Yao-Chung Lin
Life of this patent
Estimating the term…
Abstract
Coding an image that includes text content and a background is disclosed. Text portions are identified in the image. The text portions are extracted from the image to obtain a background image, where the background image includes holes corresponding to respective areas of the text portions within the image. A filled-in background image is obtained based on the background image. The filled-in background image is encoded into a compressed bitstream using a block-based encoder. The text portions is also encoded into the compressed bitstream. Encoding the text portions includes encoding respective high quality text binarization upscaled binary maps.
Claims20
A method for coding an image that includes text content and a background, comprising:
- identifying text portions in the image;
- extracting the text portions from the image to obtain a background image, wherein the background image includes holes corresponding to respective areas of the text portions within the image;
- obtaining a filled-in background image based on the background image;
- encoding, in a compressed bitstream, a flag indicating whether the image is encoded using two-layer encoding that separately encodes the text content from the background;
- encoding, into the compressed bitstream, the filled-in background image using a block-based encoder;
- and
- encoding, into the compressed bitstream, the text portions.
A device for coding an image that includes text content and a background, comprising:
- a processor configured to:
- identify text portions in the image;
- extract the text portions from the image to obtain a background image, wherein the background image includes holes corresponding to respective areas of the text portions within the image;
- obtain a filled-in background image based on the background image;
- encode, in a compressed bitstream, a flag indicating whether the image is encoded using two-layer encoding that separately encodes the text content from the background;
- encode, into the compressed bitstream, the filled-in background image using a block-based encoder;
- and
- encode, into the compressed bitstream, the text portions.
A method for decoding an image comprising:
- decoding, from a compressed bitstream, a flag indicating that the image is encoded using two-layer encoding that separately encodes text content of the image from a background image of the image;
- decoding, from the compressed bitstream, the background image of the image using a block-based decoder;
- decoding, from the compressed bitstream, respective locations of text symbols;
- and
- overlaying, based on the respective locations, the text symbols on the background image to obtain the image.
Dependencies are inferred from the claim text.