> On Jun 7, 2020, at 3:15 PM, Steve Christensen via Cocoa-dev
> wrote:
>
> For slide shows that I’ve seen, they typically display each image for several
> seconds at a time. If that’s the case, why can’t you just load the next image
> from disk on a background queue while the current image
> On Jun 7, 2020, at 3:27 AM, Gabriel Zachmann via Cocoa-dev
> wrote:
>
> For large images, this "thumbnail" can well occupy 1 GB of RAM.
That seems excessive. Shouldn’t you shrink it down to the actual screen
resolution first?
> My current approach is to calculate the amount of unused
Thanks a lot for your response.
> If that’s the case, why can’t you just load the next image from disk on a
> background queue while
That is what I'm doing, since loading the next image could take up to 9 seconds.
> the current image is being displayed and not have to worry about memory usage
For slide shows that I’ve seen, they typically display each image for several
seconds at a time. If that’s the case, why can’t you just load the next image
from disk on a background queue while the current image is being displayed and
not have to worry about memory usage needed to cache
Thanks a lot for the hints - I'll look into the different ideas.
Also thanks to Christos for his hints.
Best regards, Gabriel
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Please do
The vast majority of data used by a CGImageRef for any sufficiently
representable image is going to be its bitmap data (a 1x1 pixel image
wouldn’t), and you can calculate that by using CGImageGetBytesPerRow and its
neighbor APIs. If I recall from your previous posts, you are showing very
Good question.
Well, some users want to feed my app with image files of 100 MB, even up to 400
MB (mostly jpeg compressed).
Those images have resolutions of over 8k, sometimes over 10k.
The slideshow app needs to be able to zoom into those images with at least a
factor 2x scaling.
So I
I am developing a slideshow app; one of its features is that it keeps a history
of the last N images it has displayed. It keeps kind of a cache , where it
stores, among other things, the image returned by
CGImageSourceCreateThumbnailAtIndex(), because this is one of the expensive
operations.
