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Convert 6.4.2 Q16: unexpected 'dual' output files

Posted: 2008-06-30T11:42:53-07:00
by mikea
(Apologies if this has come up before. I haven't yet found it via a site search.) Using 6.4.2 (06/22/08 Q16) under Win XP SP2. I've only recently discovered these programs and was downright thrilled that I could use convert.exe to roll my own 'save for web' solution, providing exactly the output I needed (including color-space conversion). I have worked up a shell script that calls convert.exe and passes the following switches+arguments (all on one line, of course):

-resample 72x72 -filter Lanczos -quality 85
-profile "C:\WINDOWS\SYSTEM32\SPOOL\DRIVERS\COLOR\sRGB Color Space Profile.icm"
-resize 800x800 inputfile outputfile

... if "inputfile" were "test.tif", the script would pass output filename "test-web.jpg" to Convert.exe.

This has worked well with two of the four TIFF files I've been using for testing. All are from Nikon D3 .NEF files. One was converted to TIFF via the raw converter SilkyPix. The second was converted with Nikon Capture NX. The other two were converted with PhaseOne's CaptureOne program (version 4).

With the first two, all is well. Convert.exe does an excellent job with them. But with the two created with CaptureOne, Convert writes two output files each. If the name were "filename.tif," the output filenames would be "test-web-0.jpg" and "test-web-1.jpg". ("test-web.jpg" itself is never created.) The "-0.jpg" version looks like what I'm after (and the output quality is good). But the "-1.jpg" version is a much smaller file -- in bytes, not pixel dimensions. It is both noticeably undersaturated and noticeably blurred -- as if I had done a blur operation of some kind on the whole image in Photoshop.

Why in those two cases would Convert.exe be making two (unexpectedly named) output files per input file? Is there a switch+argument I must add to prevent this? The fact that both of the problem-child source files were written by CaptureOne is suggestive...but what might CaptureOne be doing that's different from the others?

Re: Convert 6.4.2 Q16: unexpected 'dual' output files

Posted: 2008-06-30T11:46:51-07:00
by magick
Your TIFF image most likely has the original image and a thumbnail in the same image file. Verity with the identify program. To only convert the first frame of a multi-frame image sequence, try this command:
  • convert test.tif[0] test.jpg

Re: Convert 6.4.2 Q16: unexpected 'dual' output files

Posted: 2008-06-30T12:15:54-07:00
by mikea
magick wrote:Your TIFF image most likely has the original image and a thumbnail in the same image file. Verity with the identify program. To only convert the first frame of a multi-frame image sequence, try this command:
  • convert test.tif[0] test.jpg
Perfect. Does the job exactly. Thanks!

As long as 'identify' came up...I'm looking at the usage info now for the 'identify' program. (I'm so new to these apps that I have only barely scratched the surface of the documentation.) 'Identify' by itself does display the bare-bones information showing me that there are in fact two images to contend with in some of these files.

I can use Exiftool to display a file's embedded/attached color profile in some cases. Strangely, even though the raw converters always convert to a user-selected profile, for some reason Exiftool doesn't display this info when it's run on the TIFF files (unless, apparently, they have been worked on by Photoshop). Is this possible with Identify? I see that it has a '-colorspace' switch, but it requires an argument. Is there a way to have it query a file for the attached/embedded color profile name and then just print it to the console? Thanks again...