ExifTool Forum

ExifTool => Newbies => Topic started by: cwboomer on March 19, 2015, 02:34:34 PM

Title: Channels
Post by: cwboomer on March 19, 2015, 02:34:34 PM
Is there a way to query a TIFF document and gather the names of the channels that are in an RGB document, that contains multiple additional channels. I have, for example, a document that has RGB, and 3-5 additional channels, and I want to query it with exiftools and poll the names of those other channels. I may have set them up with other names, over the course of time.
Title: Re: Channels
Post by: Phil Harvey on March 19, 2015, 07:48:17 PM
I'm not exactly sure what you are talking about.  The TIFF ComponentsConfiguration specifies the Y, Cb, Cr, R, G and B channels.  ExifTool extracts this, and any other standard information that exists (and converts them to more readable strings).

- Phil
Title: Re: Channels
Post by: cwboomer on March 20, 2015, 02:56:46 AM
thank you for replying so quickly.
In looking up the values, with -list on a file I put together, it showed up under "Alpha Channels Names". Is that an event that can be queried separately to get the filename and these results?

And just so I actually know, are these known as "TIFF Tag ExtraSamples", or is that incorrect?

IFD      Image
Code      338 (hex 0x0152)
Name      ExtraSamples
LibTiff name      TIFFTAG_EXTRASAMPLES
Type      SHORT
Count      N
Default      None
Title: Re: Channels
Post by: Phil Harvey on March 20, 2015, 06:54:58 AM
AlphaChannelsNames is is a Photoshop tag (https://exiftool.org/TagNames/Photoshop.html), not a TIFF tag.  I don't know if this is related to the TIFF ExtraSamples tags.

- Phil
Title: Re: Channels
Post by: cwboomer on March 20, 2015, 08:57:13 PM
Thank you so much. I have learned more in the past few months working with exiftool, than I have in a cumulative few years in working with photoshop. The tool has also boosted me into the unix arena.

I am going to come back for more help soon. This is simply amazing that you have put this together.