Hi,
I've been working on my cropping and scaling flow and have noticed that there are big memory spikes when resizing an image (both using ImageIO and drawing in a context). What I don't get is that I see no memory spikes when cropping an image. My mental model says that cropping should decompress the image into memory and then copy the pixels to a new image object. Is that wrong?
It depends on exactly what you're doing.
In general, a crop operation could just retain the original backing store (sharing it with the original image) and keep metadata so it "knows" that it's just a portion of it. When it draws or whatever, it would just draw that portion.
As Ken notes, depends...
Maybe some discussion here:
https://developer.apple.com/videos/play/wwdc2018/416/
Also, don't forget you can use Instruments to dig in rather than rely strictly on your mental model...it might be fun to validate that model, too 😉
Ken
