Legacy ImageMagick Discussions Archive

I have the problem that adding a -thumbnail flag to a resize command gives no decode delegate for this image format.
Resize without -thumbnail just works. Why this difference?

This works

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FOR %%G IN (*.jpg) DO (
    D:\progs\ImageMagick\convert.exe %%G -interlace plane -quality 85 "84x53>" -resize ..\thumbs\%%G 
)

This works not:

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FOR %%G IN (*.jpg) DO (
    D:\progs\ImageMagick\convert.exe %%G -interlace plane -quality 85 -thumbnail "84x53>" ..\thumbs\%%G 
)

it gives:

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convert.exe: no decode delegate for this image format `C:/DOCUME~1/Erich/LOCALS~1/
Temp/magick-jzTjvk2f' @ constitute.c/ReadImage/531.

Those magick-* files are 0bytes and do not have an extension.

I have the stand-alone version of ImageMagick, on windows xp32 sp3. Imagemagick is not in the path, nor do I have any special imagemagick environment variable defined.

Some info from identify -list format:

JNG* rw- JPEG Network Graphics
See http://www.libpng.org/pub/mng/ for details about the JNG
format.
JP2* rw- JPEG-2000 File Format Syntax
JPC* rw- JPEG-2000 Code Stream Syntax
JPEG* rw- Joint Photographic Experts Group JFIF format (70)
JPG* rw- Joint Photographic Experts Group JFIF format (70)
JPX* rw- JPEG-2000 File Format Syntax

edit: corrected the examples, missing input parameter due to wrong copying here.

I don't see how your first command can work because it has "84x53>" without a preceeding operation (-resize ??) and the convert command also requires an input and output filename whereas your command only has one filename. Both commands, as you have shown them, should fail.

Pete

Pete thanks, you were right that -resize was missing in the first example.

The mad thing is: it correctly thumbnailed the jpgs (the size is correct at least). So I do not understand what went wrong.

I've changed the parameter order. Is this correct? It runs at least.

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D:\progs\ImageMagick\convert.exe %%G -thumbnail  "84x53>" -interlace plane -quality 85  ..\thumbs\%%G

Some 0-byte files get this warning, but the error disappeared at least.

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convert.exe: Empty input file `102657.jpg' @ jpeg.c/EmitMessage/233.
convert.exe: missing an image filename `..\400-400\102657.jpg' @ convert.c/Conve
rtImageCommand/2838.

The command looks good now. You could use the DOS "if" command to test for a zero length file but either way it's best ot have something warning you of bad files.

Pete

Legacy ImageMagick Discussions Archive

Thumbnail flag in resize causes: no decode delegate for this

Thumbnail flag in resize causes: no decode delegate for this

Re: Thumbnail flag in resize causes: no decode delegate for this

Re: Thumbnail flag in resize causes: no decode delegate for this

Re: Thumbnail flag in resize causes: no decode delegate for this