# US 2013/0156310 A1 · Dynamic Image Quality Checker for use in Image Transcoding > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0156310 A1 - Document ID: US20130156310A1 - Status: Published application - Kind: A1 - Application number: 13/327,551 - Filed: 2011-12-15 - Published: 2013-06-20 - Earliest claimed: 2011-12-15 - Assignees: Microsoft Corporation - Inventors: Yisheng Yao; Ke-Cheng Huang; Emmanuel Papirakis; Patrick E. Plaisted - Web page: https://patentgrep.com/patent/US20130156310A1 ## CPC - H04N 19/154: Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion (use of rate-distortion criteria H04N19/147) - H04N 19/192: the adaptation method, adaptation tool or adaptation type being iterative or recursive - H04N 19/40: using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Described is a technology by which an image is transcoded to a desired quality measure (e.g., PSNR). A quality measure of transcoded image data is checked against a desired quality measure, and if a desired quality measure is not achieved, a different quality level is iteratively provided to attempt to re-transcode the image until the desired quality measure is achieved. ## Claims ### Claim 1 In a computing environment, a method performed at least in part on at least one processor comprising, checking a quality measure of transcoded image data obtained from an input image against a desired quality measure, and if a desired quality measure is not achieved by the quality measure of the transcoded image data, providing, a different quality level one or more times for re-transcoding until the desired quality measure is achieved. ### Claim 2 (depends on 1) The method of claim 1 wherein checking the quality measure comprises obtaining a quality measure, comprising peak signal-to-noise ratio (PSNR) or structural similarity (ssim), based upon the input image and the transcoded image data. ### Claim 3 (depends on 1) The method of claim 1 wherein checking the quality measure of the image against a desired quality measure comprises determining whether the quality measure is within a desired range of values. ### Claim 4 (depends on 1) The method of claim 1 wherein re-transcoding with a different quality level comprises decreasing a previous quality level to obtain the different quality level if the quality measure of the image is too high relative to the desired quality measure. ### Claim 5 (depends on 4) The method of claim 4 wherein decreasing the quality level comprises using a binary calculation. ### Claim 6 (depends on 1) The method of claim 1 wherein re-transcoding with a different quality level comprises increasing a previous quality level to obtain the different quality level if the quality measure of the image is too low relative to the desired quality measure. ### Claim 7 (depends on 6) The method of claim 6 wherein increasing the quality level comprises using a binary calculation. ### Claim 8 (depends on 1) The method of claim 1 wherein transcoding comprises performing a color reduction operation to obtain a number of colors, and wherein re-transcoding with a different quality level comprises performing a different color reduction operation corresponding to a different number of colors. ### Claim 9 (depends on 1) The method of claim 1 wherein checking the quality measure of the transcoded image data against the desired quality measure comprises evaluating loss compression factors. ### Claim 10 A system comprising, a quality checker mechanism configured to determine when any set of transcoded image data has a quality measure within a desired range of quality measures, and for at least for one iteration to calculate a next quality level to obtain a different set of transcoded image data having a different quality measure when a previous quality measure did not fall within the desired range of quality measures, and the quality checker mechanism further configured to identify a selected set of transcoded image data having a quality measure that falls within the quality range if one exists. ### Claim 11 (depends on 10) The system of claim 10 wherein the quality measure comprises a peak signal-to-noise ratio (PSNR) value, or structural similarity (SSIM) value. ### Claim 12 (depends on 10) The system of claim 10 wherein the set of transcoded image data corresponds to a transcoded JPEG file, PNG file, or GIF file. ### Claim 13 (depends on 10) The system of claim 10 wherein the quality checker mechanism calculates the next quality level by decreasing the quality level. ### Claim 14 (depends on 10) The system of claim 10 wherein the quality checker mechanism calculates the next quality level by increasing the quality level. ### Claim 15 (depends on 10) The system of claim 10 wherein the quality checker mechanism calculates the next quality level by increasing or decreasing the quality level using a binary calculation. ### Claim 16 One or more computer-readable media having computer-executable instructions, which when executed perform steps, comprising: (a) transcoding an image into a transcoded image based upon an input image and a quality level input to a transcoder; (b) determining a quality measure of the transcoded image; (c) if the quality measure is not within a desired range and a stop condition is not reached, changing the quality level and returning to step (a); and (d) returning a transcoded image if the quality measure of that transcoded image is within the desired range, or returning the input image if the if the quality measure is not within the desired range. ### Claim 17 (depends on 16) The one or more computer-readable media of claim 16 wherein changing the quality level comprises increasing the quality level if the quality measure is too low. ### Claim 18 (depends on 16) The one or more computer-readable media of claim 16 having further computer-executable instructions comprising, monitoring for a stop condition, including maintaining and evaluating a retry counter. ### Claim 19 (depends on 16) The one or more computer-readable media of claim 16 having further computer-executable instructions comprising, monitoring for a stop condition, including calculating a next quality level and evaluating whether the next quality level equals a previous quality level. ### Claim 20 (depends on 16) The one or more computer-readable media of claim 16 having further computer-executable instructions comprising, monitoring for a stop condition, including evaluating gain-related data.