Not able to disable auto rotate when using thumbnail_image

[becoded]

It seems that the flag auto-rotate for thumbnail_image doesn't have any effect when using vips command line.

Source file: https://github.com/ianare/exif-samples/blob/master/jpg/orientation/portrait_8.jpg

Using the following command:
vips thumbnail_image portrait_8.jpg "portrait_8-600x450.jpg[strip,background=255 255 255,Q=95]" 600 --height=450 --auto-rotate=false

As I specify to strip the metadata + don't do the auto-rotate, I would expect that my end result should be a rotated image but the images displays correctly.

vips --version
vips-8.7.0-Fri Aug 31 14:11:19 UTC 2018

[jcupitt]

Hi @becoded,

You're right, I'd expect

vips thumbnail_image portrait_8.jpg x.jpg 128 --auto-rotate=false

to not rotate, but it does. I'll have a look.

vipsthumbnail seems to only rotate with --rotate option, so that works at least.

[jcupitt]

It's because of the way that glib arg parsing works, sorry, I don't think this is directly fixable.

The best workaround would be to use vipsthumbnail instead, ie. your example would be:

vipsthumbnail portrait_8.jpg -o portrait_8-600x450.jpg[strip,background=255,Q=95] -s 600x450

I think the best solution would be to tag the auto-rotate option as deprecated, and add a new one called no-rotate which defaults to FALSE. Your command-line would then be:

vips thumbnail_image portrait_8.jpg x.jpg 128 --no-rotate

Background: glib command-line switches must take one of two forms:

1. -v or --verbose. A simple flag, meaning TRUE if present.
2. -w 12 or --width=12. A switch with a single argument. The argument can be one of several types: string, int, filename etc.

You can't mix the two styles, so a no-arg flag can't have an =arg appended to it.

See https://developer.gnome.org/glib/stable/glib-Commandline-option-parser.html

[becoded]

Hello @jcupitt

I really appreciate it that you looked into this so fast!

I don't really see your point to be honest.
If I just type vips thumbnail_image
I get

...
   auto-rotate  - Use orientation tags to rotate image upright, input gboolean
			default: true
...

How I read this is as follows:

• auto-rotate is set to true if you don't define it in the options
• if you want to change it, it requires an boolean input.

So the only way to use the option auto-rotate is the 2nd form:
--auto-rotate=true or --auto-rotate=false

So it seems that auto-rotate is configured as a simple flag but should be changed to a switch with a single argument.

[jcupitt]

I think the argument is:

• thumbnail_image has auto-rotate as an optional boolean argument.
• All boolean arguments are mapped to simple GOption switches, with --thing meaning set thing TRUE
• However, auto_rotate is default TRUE, so you can never set it FALSE on the command-line.

It was an unfortunate oversight when thumbnail_image was designed.

Anyway, use vipsthumbnail instead for now and you should be OK.

[becoded]

Will do.
Thanks again for the fast support!

[jcupitt]

OK, fixed in git master. I'll close.

[becoded]

Hello @jcupitt
I saw there was a new release with these changes included.
Is it expected that I don't see the new option if I do vips thumbnail_image
Also providing the new option gives me an error (Unknown option)

[jcupitt]

Hello, there's 8.7.1, but that's just a bugfix from 8.7.0.

This change will be in 8.8.0, due in the spring some time, or you can build from git master if you want it now.