Exif rotation

[swissspidy]

Read exif data, rotate image if necessary, remove rotation header afterwards

See https://github.com/mattiasw/ExifReader

Vips' thumbnail functions also look at exif headers and rotate if necessary. But what about the full size?

Related:

• Ensure optimized images have correct metadata #237
• https://make.wordpress.org/core/2019/10/11/updates-to-image-processing-in-wordpress-5-3/
• https://core.trac.wordpress.org/changeset/46202
• https://core.trac.wordpress.org/ticket/14459

Sample image:

(orientation: 3)

The Exif orientation flag can have nine different values from 1 to 9:

Typically, you will only get flag 1, 8, 3, 6 for digital photos. Flag 2, 7, 4, 5 represent mirrored and rotated version of images.

(source)

[swissspidy]

At the moment this doesn't seem to be an actual issue. The sample image above is always displayed correctly no matter where I look at it, and the blurhash looks correct as well. So not sure if there is really something that needs to be changed 🤷

[swissspidy]

@adamsilverstein since you brought up https://github.com/WordPress/wordpress-develop/blob/b4eeefe786100fc8a9e7d0650aeddee3825b9451/src/wp-includes/class-wp-image-editor.php#L500-L570, would love your thoughts on this, maybe you can reproduce this?

Right now it seems to "just work" and no action is needed, but maybe I'm wrong.

[swissspidy]

Good repo I found: https://github.com/recurser/exif-orientation-examples

I guess my point is: if the browser already handles this nowadays, I don't see the need for handling this also.