Hacker News Reader

Using 16-bit images won't save any memory, and may actually use more memory. The iOS graphics pipeline requires 32-bit images for rendering, so all other types of images are converted to a 32-bit texture.

If you are trying to optimize memory consumption, you need to measure memory consumption! You can't just change some code and assume your memory consumption has gone down.

View on HN

I certainly was measuring memory consumption. Many of these images are offscreen in paging scroll views (per the blog post), or stuck in caches.

Like gurgeous, I also measure memory consumption almost to a fault. Even though it appear iOS loads jpgs directly into a 32bpp RGBA bitmap, you can after that trim down the size of the image resident in memory. It makes a significant difference in memory usage according to Instruments, but slows down the loading of an image from disk. Unfortunately, like noted elsewhere in this thread, it doesn't seem possible to load a jpg directly into a 16bpp in memory representation and skip the intermediate 32bpp format.

Reply on news.ycombinator.com