use Tumbler for thumbnails
Bug #1272577 reported by
Danielle Foré
This bug affects 4 people
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Photos |
Triaged
|
Wishlist
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Unassigned |
Bug Description
No sense creating two sets of thumbnails on the disk. Let's use Tumbler to create thumbnails and drop the thumbnailing code from Shotwell.
Changed in pantheon-photos: | |
milestone: | none → loki-beta1 |
Changed in pantheon-photos: | |
milestone: | loki-beta1 → none |
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One major issue: Shotwell doesn't store fully-transformed images on disk.
Shotwell's editor is non-destructive. It stores changes (rotation, color correction, crop, etc.) in its database and applies them on-the-fly when the image is viewed within Shotwell. This is a major reason for Shotwell's internal thumbnailing. Shotwell stores fully-transformed thumbnails (including rotation) to get them on the screen as quickly as possible.
An external thumbnailer will need to know how to get that information from Shotwell's database and apply those changes exactly as Shotwell would in order to produce thumbnails that look like the final image. Those thumbnails aren't useful outside of Shotwell, as they might show images that look nothing like the image if it was loaded with a regular image viewer (like eog).
A secondary issue is that Shotwell allows the user to dynamically change the size of the thumbnail. If the thumbnail is too small, artifacts will appear when scaled up. If it's too large, Shotwell is slow to display thumbnails when the user sets them small, as it needs to load a large number of them and apply scaling. This is why Shotwell stores two sets of thumbnails, 360px and 128px. Our guiding rule is: always scale down, never scale up.