Legacy ImageMagick Discussions Archive

Brackets don't localise the gravity change to within the brackets. To get the multi-command to give the same version as the all-in-one, insert "-gravity northeast" at the start of the final command: convert .\done1\3_%filenameext% -gravity northeast -background white -splice 100x100 -gravi...

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 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 b...

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 -W...

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.

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.

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...

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>>...

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 ...

Inelegant solution (Ubuntu):

isn't a valid convert command.

Try:

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 ...

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...

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