> I don't quite understand why you need to know the aspect ratio beforehand. > Surely, there must be some display size into which the thumbnail is expected > to fit?
Ok, let's give you an example. I know i have to fit my image in something that is 100 width x 100 height and i am using the PreserveAspectCrop fill format meaning the image is scaled uniformly to fill, cropping if necessary If i don't know the aspect ratio of the image that i have to draw which size do i request? If the image is portrait i have to request (100, 0) If the image is landscape i have to request (0, 100) See http://paste.ubuntu.com/12197917/ using http://i.imgur.com/xiP0k4T.jpg as landscape.jpg and http://i.imgur.com/A2M6bnF.jpg as portrait.jpg and you'll see http://i.imgur.com/f5sEMhe.png. You can see there why we need to know the aspect ratio to achive the best quality. In the first row "Source Size Width" has the best quality while in the second row "Source Size Height" has the best quality. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to thumbnailer in Ubuntu. https://bugs.launchpad.net/bugs/1467740 Title: Lots of thumbnail requests with invalid size Status in thumbnailer package in Ubuntu: New Status in unity8 package in Ubuntu: New Bug description: When using scopes, the thumbnailer gets loads of requests with QSize(-1,-1) from the shell. For example, with a bunch of videos recorded, run up the video scope and go to "My Videos". The shell asks for a thumbnail at QSize(-1,-1) for the tiny thumbnail that appears to the left of each list entry. The problem with this is that the thumbnailer interprets this to mean "give me the largest size you can (limited to a 1920x1920 bounding box). That's very expensive, especially in terms of disk space, because that 1920 "thumbnail" ends up going into the cache, needlessly hogging space. We are about to add a qWarning message to the QML side that reports invalid QSize requests. For now, we are going to retain the old behavior, but this will turn into an error soon. The most effective way to use the thumbnailer is to simply ask for an image in the desired size, with neither width nor height of -1. The thumbnailer will efficiently produce a thumbnail for that. (We do lots of internal caching to avoid extracting or downloading a thumbnail unnecessarily.) The thumbnailer may deliver a thumbnail that is smaller than what was asked for (because it never up-scales) so, if asked for a thumbnail of size 256, it's guaranteed not to be larger, but might be smaller (if the original image is smaller than what was asked for). Could you please adjust the shell behavior to ask for specific, valid sizes only? Running a tail -f on ~/.cache/upstart/dbus.log allows you to see the requests as they are made. Each request shows the size that was asked for. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/thumbnailer/+bug/1467740/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
