Search found 6 matches

by beaudet
2017-09-20T12:17:52-07:00
Forum: Users
Topic: taking advantage of chroma subsampling with JPEG and ycbcr in pyramidal tiff files
Replies: 3
Views: 1772

Re: taking advantage of chroma subsampling with JPEG and ycbcr in pyramidal tiff files

Follow-up question: I know there was discussion elsewhere about ImageMagick's lack of support for chroma sub-sampling when JPEG compression is used in a TIFF files unless the colorspace is ycbcr. The latest I read was that it was due to a libtiff limitation. However, there are other programs such as...
by beaudet
2017-09-19T13:11:25-07:00
Forum: Users
Topic: taking advantage of chroma subsampling with JPEG and ycbcr in pyramidal tiff files
Replies: 3
Views: 1772

taking advantage of chroma subsampling with JPEG and ycbcr in pyramidal tiff files

I have an uncompressed TIFF source image that I'm converting to pyramidal tiff files with JPEG compression. I would like to take advantage of the significant space savings (3x) afforded by chrominance subsampling as as John Cupitt, the author of vips, points out here: https://github.com/jcupitt/libv...
by beaudet
2017-09-19T08:02:38-07:00
Forum: Users
Topic: tile-geometry ignored in IM 7?
Replies: 2
Views: 1310

Re: tile-geometry ignored in IM 7?

the tile geometry in use can also be discovered using the tiffinfo command
by beaudet
2017-09-15T09:23:30-07:00
Forum: Users
Topic: tile-geometry ignored in IM 7?
Replies: 2
Views: 1310

Re: tile-geometry ignored in IM 7?

I was able to verify using IIP Image server that the tile-geometry parameter is being honored. The fact that additional pages are being created is probably not a big deal since the resolution is so low. It would still be nice to know of a way to report on the tile geometry of a pyramidal tiff though...
by beaudet
2017-09-15T07:40:07-07:00
Forum: Users
Topic: tile-geometry ignored in IM 7?
Replies: 2
Views: 1310

tile-geometry ignored in IM 7?

Installed ImageMagick-7.0.7-2.x86_64.rpm and ImageMagick-libs-7.0.7-2.x86_64.rpm into RHEL7 magick -size 1024x1024 canvas:khaki canvas.jpg magick canvas.jpg -define tiff:tile-geometry=256x256 ptif:canvas.tif identify canvas.tif produces canvas.tif[0] TIFF 1024x1024 1024x1024+0+0 8-bit sRGB 4.314MiB ...