File:Lichtenstein jpeg2000 difference.png
Lichtenstein_jpeg2000_difference.png (512 × 512 pixels, file size: 394 KB, MIME type: image/png)
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Summary
DescriptionLichtenstein jpeg2000 difference.png |
The picture shows the difference pixel-by-pixel between an image and its JPEG2000 compressed version: white=no-difference; black=big-difference The original image is Image:Lichtenstein img processing test.png, that I have renamed castle.png on my hard-disk to make it simpler. The I have converted it so JPEG2000 using the "convert" utility by ImageMagik, with the following command: convert -quality 50 castle.png castle.jp2 Then I had to reconvert the JPEG2000 version to PNG to be able to read it: convert castle.jp2 castle_2000.png The I have used the following Matlab code: %read original image original=imread('castle.png'); %read compressed image compressed=imread('castle_2000.png'); original=im2double(original); compressed=im2double(compressed); error=abs(original-compressed); %amplify the error for each color layer error(:,:,1)=imadjust(error(:,:,1)); error(:,:,2)=imadjust(error(:,:,2)); error(:,:,3)=imadjust(error(:,:,3)); %invert the picture error=1-error; %write it to a file imwrite(error,'castle_error_2000.png'); |
Date | |
Source | Own work |
Author | Alessio Damato |
Other versions |
Licensing
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License.http://www.gnu.org/copyleft/fdl.htmlGFDLGNU Free Documentation Licensetruetrue |
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. | ||
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This licensing tag was added to this file as part of the GFDL licensing update.http://creativecommons.org/licenses/by-sa/3.0/CC BY-SA 3.0Creative Commons Attribution-Share Alike 3.0truetrue |
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19 May 2007
File history
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Date/Time | Thumbnail | Dimensions | User | Comment | |
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current | 10:27, 6 July 2019 | 512 × 512 (394 KB) | wikimediacommons>Alexis Jazz | Reverted to version as of 19:11, 19 May 2007 (UTC) Can't be sure if metadata, color profiles or browser compatiblity was lost. These overwrites are not needed, MediaWiki handles this. |
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