Moving image encoding device

Patent metadata

Field	Value
Publication number	US-9307245-B2
Application number	US-201314429053-A
Country	US
Kind code	B2
Filing date	Jul 29, 2013
Priority date	Sep 19, 2012
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

An updated region encoding unit detects an updated region in a frame of an inputted image signal and encodes the updated region. A retransmission candidate tile extracting unit extracts from within a screen a tile which does not belong to an updated region in a current frame and which is a partial region transmitted after encoded with a quality equal to or less than a first quality. A character likelihood estimating unit, with respect to a tile extracted by the retransmission candidate tile extracting unit, calculates a likelihood value indicating likelihood that the tile is a character region. A character-likelihood-order intra update unit selects a tile in decreasing order of the likelihood value from among tiles extracted by the retransmission candidate tile extracting unit, and encodes the tile with a second quality which is higher than the first quality and transmits the result.

First claim

The invention claimed is:

1. A moving image encoding device comprising:
at least one memory operable to store program instruction;
at least one processor operable to read said program instruction and configured by the program instruction to operate as:
an updated region encoding unit configured to detect an updated region in a frame of an inputted image signal and encode the updated region;
a retransmission candidate tile extracting unit configured to extract, from among a plurality of tiles which are partial portions of the frame, a tile which does not belong to the updated region in a current frame, the tile transmitted after encoded with a quality equal to or less than a first quality;
a character likelihood estimating unit, with respect to the tile extracted by the retransmission candidate tile extracting unit, configured to calculate a likelihood value indicating likelihood that the tile is a character region; and
a character-likelihood-order intra update unit configured to select the tile in decreasing order of the likelihood value from among the tiles extracted by the retransmission candidate tile extracting unit and, for transmission, encode the tile with a second quality which is higher than the first quality.

2. The moving image encoding device according to claim 1 , wherein the character-likelihood-order intra update unit configured to perform the encoding of the tile so that a total amount of outputted codes in the current frame does not exceed a target amount of codes.

3. The moving image encoding device according to claim 1 , wherein the character-likelihood-order intra update unit configured to select a predetermined number of the tiles or less.

4. The moving image encoding device according to claim 1 , wherein the character-likelihood-order intra update unit configured to end the selection and encoding of the tile when it reaches end target time.

5. The moving image encoding device according to claim 1 , wherein the character-likelihood-order intra update unit configured to perform the selection and encoding of the tile one by one.

6. The moving image encoding device according to claim 1 , wherein the character-likelihood-order intra update unit configured to extract and encode all the tiles with the likelihood values exceeding a first threshold, and thereafter, extract all the tiles with the likelihood values exceeding a second threshold which is smaller than the first threshold and performs the encoding.

7. The moving image encoding device according to claim 1 , wherein the character likelihood value estimating unit configured to obtain edge strength for each pixel in the frame and calculate a variance value of the edge strength in the tile as the likelihood value.

8. A moving image encoding method comprising:
detecting an updated region in a frame of an inputted image signal and encoding the updated region;
extracting, from among a plurality of tiles which are partial regions of the frame, a tile which does not belong to the updated region in a current frame, the tile transmitted after encoded with a quality equal to or less than a first quality;
with respect to the extracted tile, calculating a likelihood value indicating likelihood that the tile is a character region; and
selecting the tile in decreasing order of the likelihood value from among the extracted tiles and, for transmission, encoding the tile with a second quality which is higher than the first quality.

9. A non-transitory computer-readable medium storing a computer program comprising instructions for causing a computer to function as:
an updated region encoding unit configured to detect an updated region in a frame of an inputted image signal and encode the updated region;
a retransmission candidate tile extracting unit configured to extract, from among a plurality of tiles which are partial regions of the frame, a tile which does not belong to the updated region in a current frame, the tile transmitted after encoded with a quality equal to or less than a first quality;
a character likelihood estimating unit, with respect to the tile extracted by the retransmission candidate tile extracting unit, configured to calculate a likelihood value indicating likelihood that the tile is a character region; and
a character-likelihood-order intra update unit configured to select the tile in decreasing order of the likelihood value from among tiles extracted by the retransmission candidate tile extracting unit and, for the transmission, encode the tile with a second quality which is higher than the first quality.

Assignees

• Nec Corp

Inventors

• Takada Jun

Classifications

• H04N19/17

  the unit being an image region, e.g. an object · CPC title

• H04N19/107 Primary

  between spatial and temporal predictive coding, e.g. picture refresh · CPC title

• H04N19/507

  using conditional replenishment · CPC title