# US 2010/0166326 A1 · Method and apparatus for encoding/decoding image in bitmap format > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0166326 A1 - Document ID: US20100166326A1 - Status: Published application - Kind: A1 - Application number: 12/550,461 - Filed: 2009-08-31 - Published: 2010-07-01 - Earliest claimed: 2008-12-31 - Assignees: Samsung Electronics Co., Ltd. - Inventors: Young-hoon JEONG - Web page: https://patentgrep.com/patent/US20100166326A1 ## CPC - G06T 7/11: Region-based segmentation - G06T 7/194: involving foreground-background segmentation - H04N 19/117: Filters, e.g. for pre-processing or post-processing (sub-band filter banks H04N19/635) - H04N 19/14: Coding unit complexity, e.g. amount of activity or edge presence estimation (H04N19/146 takes precedence) - H04N 19/182: the unit being a pixel - H04N 19/46: Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence) - H04N 19/80: Details of filtering operations specially adapted for video compression, e.g. for pixel interpolation (H04N19/635, H04N19/86 take precedence) - G06T 2207/30176: Document - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An apparatus and a method of encoding/decoding an image are provided. The method includes generating a bitmap table by mapping a quantized image, that is quantized according to a predetermined bit-depth, to a map table, and setting a bitmap index corresponding to each pixel location of the quantized image with reference to the bitmap table; setting a fixed filter index corresponding to an image of each pixel of the image by analyzing local characteristics of the image; generating bitmap data by adding the filter index to the bitmap index; extracting a bitmap index, a bitmap table, and a filter index from the bitmap data; extracting an encoded image mapped to the bitmap index from the bitmap table; and filtering the extracted encoded image based on a filter corresponding to the filter index. ## Claims ### Claim 1 A method of encoding an image, the method comprising: generating a bitmap table by mapping a quantized image, that is quantized according to a predetermined bit-depth, to a map table, and setting a bitmap index corresponding to each pixel location of the quantized image with reference to the bitmap table; setting a fixed filter index corresponding to an image of each pixel of the image by analyzing local characteristics of the image; and generating bitmap data by adding the filter index to the bitmap index. ### Claim 2 (depends on 1) The method of claim 1, wherein the generating the bitmap table and the setting the bitmap index comprise: quantizing image data input through a user interface to the predetermined bit-depth to generate the quantized image; generating the bitmap table by mapping the quantized image data to a map table pixels-by-pixel; and generating the bitmap index representing an image location of each pixel of the quantized image stored in the bitmap table. ### Claim 3 (depends on 1) The method of claim 1, wherein the setting of the filter index comprises: selecting a pre-defined filter for each pixel of the image according to local image characteristics between a current pixel and neighboring pixels; and indexing the selected filter. ### Claim 4 (depends on 3) The method of claim 3, wherein the local characteristics comprise at least one of a brightness difference between the current pixel and the neighboring pixels and an average value between the current pixel and the neighboring pixels. ### Claim 5 (depends on 3) The method of claim 3, wherein filter information corresponding to the filter index is shared by an encoder and a decoder. ### Claim 6 (depends on 3) The method of claim 3, wherein the selecting the filter comprises: selecting a high-frequency pass filter if a difference between a current pixel value and neighboring pixel values is equal to or greater than a threshold value; and selecting a low-frequency pass filter if the difference between the current pixel value and the neighboring pixel values is lower than the threshold value. ### Claim 7 (depends on 3) The method of claim 3, wherein the generating the bitmap data comprises adding the filter index to the bitmap index on a pixel-by-pixel basis. ### Claim 8 A method of decoding an image, the method comprising: extracting a bitmap index, a bitmap table, and a filter index from bitmap data; extracting an image mapped to the bitmap index from the bitmap table and storing the extracted image in a storage unit; and filtering the extracted image based on a filter corresponding to the filter index. ### Claim 9 (depends on 8) The method of claim 8, wherein the filtering of the extracted image comprises filtering a current pixel value and neighboring pixel values by using the filter corresponding to the filter index. ### Claim 10 A method of encoding and decoding an image, the method comprising: encoding an image by: generating a bitmap table by mapping a quantized image, that is quantized according to a predetermined bit-depth, to a map table, and setting a bitmap index corresponding to each pixel location of the quantized image with reference to the bitmap table; setting a fixed filter index regarding an image of each pixel of the image by analyzing local characteristics of the image; and generating bitmap data by adding the filter index to the bitmap index; and decoding an encoded image by: extracting a bitmap index, a bitmap table, and a filter index from the bitmap data; extracting the encoded image mapped to the bitmap index from the bitmap table; and filtering the extracted encoded image based on a filter corresponding to the filter index. ### Claim 11 An apparatus for encoding an image, the apparatus comprising: a bitmap data creator which generates a bitmap table by using a quantized image that is quantized to a predetermined bit-depth, and sets a bitmap index corresponding to each pixel location of the quantized image with reference to the bitmap table; a filter index creator which sets a fixed filter index regarding an image of each pixel of the image by analyzing local image characteristics of the image; and a merging unit which merges the bitmap index created by the bitmap data creator and the filter index created by the filter index creator. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the filter index creator comprises: an arithmetic calculator which extracts local image characteristic parameters between a current pixel and neighboring pixels; and a filter selector which selects a pre-defined filter for each pixel according to the local image characteristic parameters extracted by the arithmetic calculator and indexes the selected filter. ### Claim 13 An apparatus for decoding an image, the apparatus comprising: a bitmap data restorer which extracts a pixel value mapped to a bitmap table according to a bitmap index; and an adaptive filtering unit which filters a current pixel and neighboring pixels, which are extracted by the bitmap data restorer, according to a filter corresponding to a filter index assigned to the bitmap index. ### Claim 14 (depends on 1) A computer readable recording medium having recorded thereon a computer program for executing the method of claim 1. ### Claim 15 (depends on 8) A computer readable recording medium having recorded thereon a computer program for executing the method of claim 8.