ExifTool Forum

ExifTool => Bug Reports / Feature Requests => Topic started by: fpria on January 23, 2022, 12:19:33 PM

Title: PSD file ImageData compression tag
Post by: fpria on January 23, 2022, 12:19:33 PM
I'm having trouble reading whether the PSD file is compressed or not.
In Photoshop settings you can change whether the file should be compressed or not.
(https://i.ibb.co/ysKgpCy/dialog.jpg)

Regardless of how I save the file, ExifTool always returns the "Compression" tag value as RLE.

My steps to reproduce:

Phil, can you confirm if it's a bug in ExifTool or not?


Title: Re: PSD file ImageData compression tag
Post by: StarGeek on January 23, 2022, 12:29:10 PM
Try using the command in FAQ #3 (https://exiftool.org/faq.html#Q3) to make sure you are looking at all the tags, including duplicated named tags, as well as the locations those tags are in.  Also, the actual tag you really want may be a different tag.
Title: Re: PSD file ImageData compression tag
Post by: fpria on January 23, 2022, 12:37:03 PM
Quote from: StarGeek on January 23, 2022, 12:29:10 PM
Try using the command in FAQ #3 (https://exiftool.org/faq.html#Q3) to make sure you are looking at all the tags, including duplicated named tags, as well as the locations those tags are in.  Also, the actual tag you really want may be a different tag.

I confirm, I am checking the correct tag.
Title: Re: PSD file ImageData compression tag
Post by: Phil Harvey on January 23, 2022, 09:24:19 PM
Can you post 2 identical (small) files, one compressed and one not?

- Phil
Title: Re: PSD file ImageData compression tag
Post by: fpria on January 24, 2022, 01:23:31 AM
Two files here, one compressed, one not.
Title: Re: PSD file ImageData compression tag
Post by: Phil Harvey on January 24, 2022, 07:52:47 AM
You're right.  The compression values are the same.  I can't say why, but ExifTool is extracting them properly.

- Phil

> exiftool uncompressed.psd compressed.psd -compression -a -G1
======== /Users/phil/Desktop/uncompressed.psd
[IFD0]          Compression                     : Uncompressed
[IFD1]          Compression                     : JPEG (old-style)
[Photoshop]     Compression                     : RLE
======== /Users/phil/Desktop/compressed.psd
[IFD0]          Compression                     : Uncompressed
[IFD1]          Compression                     : JPEG (old-style)
[Photoshop]     Compression                     : RLE
    2 image files read
Title: Re: PSD file ImageData compression tag
Post by: blue-j on January 27, 2022, 10:54:04 PM
Seems like a bug in Photoshop.  The value should be "0" or "RAW" for the uncompressed PSD.  The compressed document looks correct (PSD compression is RLE).  I hope you might find the time to report it!

https://www.adobe.com/products/wishform.html

- J
Title: Re: PSD file ImageData compression tag
Post by: fpria on February 02, 2022, 01:59:19 AM
Yes, it's probably a Photoshop bug. Nevertheless, the files open, so Photoshop probably doesn't use the value of the "Compression" field at all.
Do you know a method on how to recognize if data is RLE compressed or not without fixing this bug in PS?
Title: Re: PSD file ImageData compression tag
Post by: fpria on February 02, 2022, 06:16:16 AM
Update:
I found that ImageMagick correctly recognizes my files. The compressed ones shows the ZIP value in Compresssion field.
According to Adobe standards, PSD files support this compression type.