Image:JPEG JFIF and 2000 Comparison.png
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Full resolution (720 × 672 pixels, file size: 550 KB, MIME type: image/png)
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[edit] Summary
This image is a PNG for a comparison between JPEG (plain, JFIF) and JPEG 2000. I (Shlomi Tal) cut a chunk of the photo (576×224 out of the original 1024×768, to be exact) with the GIMP, then saved to PPM. I then generated a JPEG version of it with a quality of 30 (on the IJG scale), yielding a file size of 11,502 bytes, computed as approximately 1/33.65 of the size of the uncompressed image. After that, I generated a JPEG 2000 version with a compression ratio of 1:33.65, yielding a size of 11,406 bytes. Finally I converted both images to PPM, created the captions (144×224 each) for the three images, stitched them all into one image and converted them to PNG with 0.45455 gamma. With pngcrush I added the text chunks and optimised the file.
I chose quality 30 because compression artifacts are guaranteed at that compression level. The reference uncompressed image is from my camera in lossless mode. The PNG is not interlaced, for I deem interlacing fit only for critical images (such as image maps for navigation) or previewing (which on Wikimedia is taken care of by the thumbnails).
[edit] Licensing
File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Dimensions | User | Comment | |
|---|---|---|---|---|
| current | 03:18, 19 January 2008 | 720×672 (550 KB) | CountingPine | (Losslessly reduce file size) |
| 18:40, 24 June 2006 | 720×672 (571 KB) | Shlomital | (Comparison image for JPEG and JPEG 2000) |
