UIWebview can not display some large size image?

what's biggest size image can UIWebvi开发者_C百科ew handle? the origin image size is: width 700 pixels, height 6900 pixels, And uiwebview display nothing.

iOS has the 3MB size limitation. the image size (width x height) must less than 3 * 1024*1024

I've discovered from some testing a limit on my html5 canvasses of 768*4096, or 3MB at 1 byte per pixel. The same resolution is enforced for images, as its not the original image size that matters, but the size of the bitmap that is rendered on the screen..