Bug report: EXIF comment not extracted

[dev-null-2007]

Description of the bug
EXIF comments added to JPEGs with exiftool (12.00) are not being extracted by the 'Extract EXIF' operation. Linux' file utility (file-5.11 on CentOS 7.7) successfully outputs the comment, so I believe it is being added correctly.

To Reproduce
Steps to reproduce the behaviour:

1. Load the provided test.jpg image (embedded under 'Additional Context') into the input
2. Add an 'Extract EXIF' operation
3. [Auto-]Bake
4. Note '0 tags extracted' in output

Expected behaviour
The EXIF comment 'This comment is in EXIF' should be in the output pane.

Screenshots

Desktop (if relevant, please complete the following information):

• OS: Windows 10
• Browser: Firefox 78.6.1esr (64-bit)

CyberChef debugging information:

• Version: 9.21.0
• Compile time: 12/06/2020 12:53:19 UTC
• User-Agent:
  Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0
• Link to reproduce

Additional context
Sample image test.jpg:

Hexdump of first 192 bytes of test.jpg:

[dev-null-2007]

Oh, and the test image was created with ImageMagick and exiftool as follows:

convert -size 1024x96 xc:white -font "DejaVu-Sans-Book" -pointsize 48 -fill black -draw "text 64, 50 'This image has an EXIF comment'" test.jpg

exiftool -comment="This comment is in EXIF" test.jpg

[git-emil]

Afais there isn't an EXIF tag named "comment". You are writing a file tag.

exiftool test.jpg -comment -G1
[File] Comment : This comment is in EXIF

[dev-null-2007]

Ahh, OK, I wasn't aware of that distinction - thanks! Personally I'd want it to display any potentially relevant metadata from the image, though I understand that, since the operation is 'Extract EXIF', it makes sense to limit it to strictly EXIF tags.

While playing around to understand the distinction better, I observed that [IFD0] ImageDescription is displayed by the operation, but [ExifIFD] UserComment is not. Both are included in the EXIF 2.32 specification - should UserComment be displayed, or is there something else I'm failing to grok?

[n1474335]

I'd say that we should be displaying comments. If anyone would like to submit a PR, we will accept it.