ExifTool Forum

Hi Phil,

Thanks for this piece of work that I am new with and trying to learn to work with.

I am trying to to extract Image data from an ITC file with the following command :
exiftool -b -itc:ImageData art.itc > art.png (this works great)

but I would like to do the same but to save the output to a file with the extension corresponding to : exiftool -itc:ImageType art.itc
The reason for this is that in my recollection the embedded data in ITC can also be a jpg file.

I'd like to combine both with something like this (doesn't work):
exiftool -b -itc:ImageData art.itc > art.${-itc:ImageType art.itc}

What am I missing? how is it suppose to be passed to the shell?

Thanks for your help

The way to do this is to run 2 commands:

exiftool -ext itc -if '$imageType eq "PNG"' -itc:imagedata -b -w png DIR
exiftool -ext itc -if '$imageType eq "JPEG"' -itc:imagedata -b -w jpg DIR

where DIR is the name of a directory containing the ITC files.

Note: the quoting above is for Mac/Linux.  Interchange the single and double quotes if you are running on Windows.

- Phil

Edit: Using some of the more advanced features allows this to be done in a single command...

exiftool -if '$imageType eq "PNG"' -w png -execute -if '$imageType eq "JPEG"' -w jpg -common_args -ext itc -itc:imagedata -b DIR

Edit2:  Hmmm.  I just tried this to be sure I got the command right, and noticed a funny quirk that keeps this from working.  I will look into fixing this, but until then, do this:

exiftool -ext itc -if '$imageType =~ /PNG/' -itc:imagedata -b -w png DIR
exiftool -ext itc -if '$imageType !~ /PNG/' -itc:imagedata -b -w jpg DIR

or

exiftool -if '$imageType =~ /PNG/' -w png -execute -if '$imageType !~ /PNG/' -w jpg -common_args -ext itc -itc:imagedata -b DIR

(the problem is that for some reason the print conversion isn't getting applied to $imageType, so I changed the test to work on the unconverted value)

Edit3: It turns out that the print conversion is being disabled by -b (which makes sense), but this also applies to tags in the -if condition (which we don't want here).  I'm still working on a solution...

Thanks a lot for your fast reply  ;D
I tried the second edit options and they work like a charm.

Is there a way to get the value from a tag by its "identifier" because it seems to me that the output of -itc:imagetype (or any other tag) is a string containing :  "Image Type                      : PNG" instead of a value like 'PNG' (this is at least the output when implemented in an applescript)

I have some last silly questions:
what does the $ in $imageType represents? is it linked to -itc:imageType? how could exiftool link both of them as -itc:ImageType has not been defined in command?

Thanks again for your help. I will use your method for now  :)

G.

Quote from: Georges75 on November 09, 2011, 08:11:56 AM
Is there a way to get the value from a tag by its "identifier" because it seems to me that the output of -itc:imagetype (or any other tag) is a string containing :  "Image Type                      : PNG" instead of a value like 'PNG' (this is at least the output when implemented in an applescript)

Yes.  There are a multitude of output formats.  The -b option returns only the value of the tag, and doesn't include the tag description.  But I'm not sure exactly what you are looking for.  Also see the -s option (use -s -S to drop the description and tag name from the output when not using -b).

QuoteI have some last silly questions:
what does the $ in $imageType represents? is it linked to -itc:imageType? how could exiftool link both of them as -itc:ImageType has not been defined in command?

I could have used $itc:imagetype in the -if condition with the same result (since there aren't any other ImageType tags in the file).  The $ is just a prefix to introduce a tag name in the expression.  See the -if option documentation (https://exiftool.org/exiftool_pod.html#item__2dif_expr) for details.

- Phil

Great thanks for your help, you answered my questions.
I will keep digging into the different command options.

Glad to clear things up.

Regarding the unexpected behaviour with the -b option, I will add this note to the -if documentation:

            Note that the -n and -b options also apply to tags used in EXPR.

Also, for this tag (ITC ImageType), I think it is best if I change the decoding to convert the value earlier, rather than using the current lookup table.  If I do this, then the original commands I suggested will work.  This will be implemented  in the next release (version 8.70).

- Phil

ExifTool 9.23 adds a new -W (upper case) option that provides this functionality.

exiftool -a -b -itc:imagedata -W %d%f-%t%c.%s DIR

This writes ITC:ImageData to a file with the same name as the original but with the tag name added (and an index, in case there are more than one ImageData tags, which is why I added the -a option, even though I don't know if it is possible to have multiple ImageData tags).  The "%s" gives the file an extension appropriate to the data type (".png", ".jpg", etc).  You can extract multiple embedded images with this single command.

- Phil