[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 --- Comment #16 from Tim Starling tstarl...@wikimedia.org 2011-04-13 06:41:09 UTC --- As for measuring peak memory usage, check out my blog post on the subject: http://tstarling.com/blog/2010/06/measuring-memory-usage-with-strace/ -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 --- Comment #14 from Bryan Tong Minh bryan.tongm...@gmail.com 2011-04-12 22:01:44 UTC --- I poked a bit at sharpening in r85207. It still looks a bit worse than ImageMagick, even though the convolution matrix should match the IM sharpening parameters. As for the libpng thing, PNG is not marked as PIO in VIPS, so it might be that it will just try to decompress the entire file into memory. Somebody should look into the peak memory usage when scaling PNGs. I have no clue on how to do so unfortunately. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 --- Comment #15 from Tim Starling tstarl...@wikimedia.org 2011-04-13 04:40:37 UTC --- (In reply to comment #14) As for the libpng thing, PNG is not marked as PIO in VIPS, so it might be that it will just try to decompress the entire file into memory. Somebody should look into the peak memory usage when scaling PNGs. I have no clue on how to do so unfortunately. Using the same source image as my tests in bug 23258, except pre-converted to PNG, the memory usage was 18MB for VIPS, and 411MB for ImageMagick. Memory usage in VIPS was low even if I used interlaced encoding in the source image. Note that im_tiff2vips and im_jpeg2vips are also marked WIO, but reading TIFF and JPEG images uses a small amount of memory nonetheless. I think file format handlers are a special case. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 --- Comment #11 from Bryan Tong Minh bryan.tongm...@gmail.com 2011-03-28 16:28:37 UTC --- (In reply to comment #9) (In reply to comment #8) Fixed the scaling in r84635. I was made aware of the vipsthumbnail program. This uses the sharpening that is also done in IM. See http://www.vips.ecs.soton.ac.uk/index.php?title=What%27s_New_in_7.22#vipsthumbnail The problem with vipsthumbnail is that it stores the uncompressed image. For a large image, it could take gigabytes of disk space. ImageMagick does this also, that's one of the reasons we want to get rid of it. Well, we'll have to do that anyway for non random accessible images (PNG, non tiled TIFF); they need to be converted to a .v file on disk, and as far as I know .v is uncompressed. So if that is your objection to VIPS we need to find another solution, such as writing a PNG reader that supports random access. Should be possible as the PNG format is line based (but I don't know about zlib). -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 Max Semenik maxsem.w...@gmail.com changed: What|Removed |Added CC||maxsem.w...@gmail.com --- Comment #12 from Max Semenik maxsem.w...@gmail.com 2011-03-28 16:58:07 UTC --- (In reply to comment #11) So if that is your objection to VIPS we need to find another solution, such as writing a PNG reader that supports random access. Should be possible as the PNG format is line based (but I don't know about zlib). libpng supports line-by-line reading. As the matter of fact, VIPS uses it to handle PNGs. I uses it for my pngds rewrite, which stopped on downscaling. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 --- Comment #13 from Tim Starling tstarl...@wikimedia.org 2011-03-28 22:29:53 UTC --- (In reply to comment #12) libpng supports line-by-line reading. As the matter of fact, VIPS uses it to handle PNGs. I uses it for my pngds rewrite, which stopped on downscaling. Right, VIPS can buffer several lines from libpng, do a block average, and then write out a line of output. Almost no intermediate storage space is required. That's why we want it. Sharpening is done on the downscaled image, not the original image. It's feasible to store the downscaled unsharpened image so that it can be fed into another run of VIPS or into ImageMagick. We just want to avoid storing the uncompressed unscaled image. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 --- Comment #10 from Jeff G. rsyqfiojg...@spammotel.com 2011-03-25 20:41:40 UTC --- (In reply to comment #9) The problem with vipsthumbnail is that it stores the uncompressed image. For a large image, it could take gigabytes of disk space. ImageMagick does this also, that's one of the reasons we want to get rid of it. Can either one be made to use a compressed filesystem for storage, or modified to store compressed images? -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 --- Comment #9 from Tim Starling tstarl...@wikimedia.org 2011-03-25 02:01:54 UTC --- (In reply to comment #8) Fixed the scaling in r84635. I was made aware of the vipsthumbnail program. This uses the sharpening that is also done in IM. See http://www.vips.ecs.soton.ac.uk/index.php?title=What%27s_New_in_7.22#vipsthumbnail The problem with vipsthumbnail is that it stores the uncompressed image. For a large image, it could take gigabytes of disk space. ImageMagick does this also, that's one of the reasons we want to get rid of it. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 --- Comment #8 from Bryan Tong Minh bryan.tongm...@gmail.com 2011-03-23 22:07:12 UTC --- Fixed the scaling in r84635. I was made aware of the vipsthumbnail program. This uses the sharpening that is also done in IM. See http://www.vips.ecs.soton.ac.uk/index.php?title=What%27s_New_in_7.22#vipsthumbnail -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 --- Comment #6 from Bryan Tong Minh bryan.tongm...@gmail.com 2011-03-21 18:47:53 UTC --- I've changed to im_shrink in r84471. The problem however is that due to rounding, the results may be inaccurate, i.e. images of 179px wide instead of 180px. The result is then that the browser upsizes the image again. Other options would be im_affine, but that uses a bilinear interpolation, which if I understand correctly is causing poor results similar to im_resize_linear. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990
--- Comment #7 from Tim Starling tstarl...@wikimedia.org 2011-03-21 23:42:16
UTC ---
(In reply to comment #6)
I've changed to im_shrink in r84471. The problem however is that due to
rounding, the results may be inaccurate, i.e. images of 179px wide instead of
180px. The result is then that the browser upsizes the image again.
There's 53 bits of precision in a floating-point number, you should be able to
manipulate these tiny integers without rounding errors.
/* Prepare output. Note: we round the output width down!
*/
...
out-Xsize = in-Xsize / xshrink;
out-Ysize = in-Ysize / yshrink;
typedef struct im__IMAGE {
...
int Xsize;
int Ysize;
If you offset the destination sizes by 0.5px, then the output size should
always be accurate.
You need to add sharpening. I discussed sharpening on bug 23258. Note that
sharpening is only necessary for images which are resized by significant
factor, see $wgSharpenReductionThreshold.
For small images that are resized to a size that is only slightly smaller, you
should use a VIPS function that has interpolation. For PagedTiffHandler, we
could get away with ignoring this case, but if we use VIPS to scale all images,
then we have to think about every possible case.
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[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 Bryan Tong Minh bryan.tongm...@gmail.com changed: What|Removed |Added Status|NEW |RESOLVED Resolution||FIXED --- Comment #4 from Bryan Tong Minh bryan.tongm...@gmail.com 2011-03-20 15:41:47 UTC --- The palette and grayscale handling has been fixed in the latest unreleased VIPS version, so this is done. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 Bryan Tong Minh bryan.tongm...@gmail.com changed: What|Removed |Added Blocks||28135 -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 --- Comment #5 from Tim Starling tstarl...@wikimedia.org 2011-03-20 23:18:29 UTC --- (In reply to comment #1) Bug 24984#c13 seems to indicate that Tim supports it. My initial comments about VIPS were on bug 23258. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 --- Comment #3 from Bryan Tong Minh bryan.tongm...@gmail.com 2011-03-18 23:11:27 UTC --- It's done as extension VipsScaler (r84281), but needs a bit of workaround for non RGBA images as VIPS is broken. I already know the workaround of greyscale images, but I'm waiting on the reply of the maintainers for palette based images. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 Mark A. Hershberger m...@everybody.org changed: What|Removed |Added Priority|Normal |Low --- Comment #2 from Mark A. Hershberger m...@everybody.org 2011-02-18 22:30:23 UTC --- Jeff, Priority settings are explained here: http://www.mediawiki.org/wiki/Bugmeister/Bugzilla -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 Jeff G. rsyqfiojg...@spammotel.com changed: What|Removed |Added Priority|Low |Normal CC||rsyqfiojg...@spammotel.com --- Comment #1 from Jeff G. rsyqfiojg...@spammotel.com 2011-02-14 03:56:02 UTC --- Bug 24984#c13 seems to indicate that Tim supports it. Lack of support for 12.5MP images, including PNG and TIFF, is negatively impacting multiple projects' scalability. VIPS implementation should save much RAM on the image scalers, allowing them to be more efficient and effective in RAM bottleneck situations. I have reverted the unexplained downgrade in importance. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
[Bug 25990] Add VIPS image scaling support to MediaWiki
https://bugzilla.wikimedia.org/show_bug.cgi?id=25990 Mark A. Hershberger m...@everybody.org changed: What|Removed |Added Priority|Normal |Low CC||m...@everybody.org -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email --- You are receiving this mail because: --- You are the assignee for the bug. You are on the CC list for the bug. ___ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
