Search found 11817 matches

by snibgo
2010-03-04T05:01:20-07:00
Forum: Users
Topic: Can someone explain what the difference is?
Replies: 8
Views: 16389

Re: Can someone explain what the difference is?

I haven't tested this, but I suspect the problem is "-gravity". In the all-in-one command, the value "northeast" is carried through until you change it to "center". In the separate commands, it will be reinitialise (to "northwest"?) at each command.
by snibgo
2010-03-04T02:06:28-07:00
Forum: Users
Topic: repairing jpegs
Replies: 23
Views: 65652

Re: repairing jpegs

By comparing imgfoo.jpg, a valid jpg file, the JPEG spec at http://www.w3.org/Graphics/JPEG/jfif3.pdf, and /usr/share/ImageMagick-6.4.5/config/magic.xml which contains the line: <magic name="JPEG" offset="0" target="\377\330\377"/> it seems imgfoo contains 21 spurious bytes at the start. These can b...
by snibgo
2010-03-04T01:00:21-07:00
Forum: Users
Topic: libMagickCore.so.3
Replies: 6
Views: 22079

Re: libMagickCore.so.3

Hi Bonzo. I can't remember if you run Mac, Windows or *nix. On Ubuntu, I have spent a frustrating few days compiling IM and especially ffmpeg, and all their various dependancies. It turns out the trick for IM (and ffmpeg) both is to ensure I have done both: $ export LDFLAGS="-L/usr/local/lib -Wl,-rp...
by snibgo
2010-03-03T12:50:30-07:00
Forum: Users
Topic: SAve lossless copies of images (JP2 -> JP2)
Replies: 3
Views: 7884

Re: SAve lossless copies of images (JP2 -> JP2)

JPEG 2000 can be lossy, so I would guess the exact command/parameters would be relevant if you want it to be lossless.

You might post a link to the image.

And you might update IM.
by snibgo
2010-03-03T12:30:42-07:00
Forum: Users
Topic: repairing jpegs
Replies: 23
Views: 65652

Re: repairing jpegs

Have you looked at the first 4 (or whatever) magic bytes? Maybe that's all that is wrong. If so, a simple C program could fix it.
by snibgo
2010-03-03T01:43:20-07:00
Forum: Users
Topic: How to identify dropframes/missing frames
Replies: 7
Views: 15469

Re: How to identify dropframes/missing frames

I'm currently converting my brain from Windows. The actual script isn't important, except as a proof of concept. You would have to determine how to process the output numbers, perhaps highlighting returned values that are either higher or lower than expected. As you say, 0 = no change. I reckon it s...
by snibgo
2010-03-02T22:57:30-07:00
Forum: Users
Topic: How to identify dropframes/missing frames
Replies: 7
Views: 15469

Re: How to identify dropframes/missing frames

It works quite well. #!/bin/bash rm framediffs.lis ffmpeg -i MPEG0004.AVI f%d.png framenum=1 while [ $framenum -lt 50 ] do file1=f$(( $framenum )).png file2=f$(( $framenum + 1 )).png compare -metric RMSE $file1 $file2 NULL: 2>diff.lis fdiff=`cat diff.lis |cut -d ' ' -f 1` echo $file1 $file2 $fdiff>>...
by snibgo
2010-03-02T20:32:58-07:00
Forum: Users
Topic: How to identify dropframes/missing frames
Replies: 7
Views: 15469

Re: How to identify dropframes/missing frames

compare -metric RMSE f200.png f201.png NULL: will return a numerical measure of the difference between the two frames. Higher numbers are more different. You could write a script to generate a list of such differences, then look for entries that are peaks, or are more than say 10% greater then the ...
by snibgo
2010-03-02T10:24:13-07:00
Forum: Users
Topic: Resizing to 100% x 1pixel
Replies: 3
Views: 8087

Re: Resizing to 100% x 1pixel

Inelegant solution (Ubuntu):

Code: Select all

convert input.png -resize `convert input.png -format %[fx:w] info:`x1! output.png
by snibgo
2010-03-02T09:50:11-07:00
Forum: Users
Topic: mac os 10.4
Replies: 2
Views: 6175

Re: mac os 10.4

by snibgo
2010-03-02T09:08:15-07:00
Forum: Users
Topic: debian: no code delegate, but they are listed [6.5.9-10]
Replies: 2
Views: 7361

Re: debian: no code delegate, but they are listed [6.5.9-10]

Code: Select all

convert configure logo:logo.jpg
isn't a valid convert command.

Try:

Code: Select all

convert logo: logo.jpg
by snibgo
2010-03-01T17:50:10-07:00
Forum: Users
Topic: Varying transparency according to rgb values
Replies: 11
Views: 21393

Re: Varying transparency according to rgb values

I suggest you look at images in a program such as Gimp that shows transparency against a chequered background, so you can see it. Then try to define your requirements. Your starter image has a large area that is transparent black. (Gimp shows it as transparent. In Gimp, I anti-erase it, showing the ...
by snibgo
2010-03-01T17:00:13-07:00
Forum: Users
Topic: Varying transparency according to rgb values
Replies: 11
Views: 21393

Re: Varying transparency according to rgb values

The docs say: copy-* ... If the channel specified does not exist in the source image, (which can only happen for methods, 'copy-opacity' or 'copy-black') then it is assumed that the source image is a special grayscale channel image of the values to be copied. But "-colorspace gray" is more explicit....
by snibgo
2010-03-01T15:53:54-07:00
Forum: Users
Topic: Varying transparency according to rgb values
Replies: 11
Views: 21393

Re: Varying transparency according to rgb values

I learn from the best. fmw's version uses brackets so we don't need that second negate. My version with brackets is:

convert input.png -alpha on \( +clone -alpha off -negate \) -compose copyOpacity -composite output.png
by snibgo
2010-03-01T15:38:01-07:00
Forum: Users
Topic: PDF: auto crop and bleed mark detection
Replies: 1
Views: 5762

Re: PDF: auto crop and bleed mark detection

See "How crop a PDF file " 3 days ago in this forum.