loadImage does not work for ios if canvas option is set to true

[zengxinzhy]

Hi Sebastian:

I'm not sure is it a good way to describe the problem.

The test demo is fairly simple, you can access it via:
http://canvas-load-image-test.s3-website-us-east-1.amazonaws.com/

If canvas option is set to true, loadImage function won't work for my iPhone 4S. I've tried the demo in desktop browser and Nexus, it works fine for those devices.

However, if we set canvas to false and then resize the image using {canvas: true}, it will work, just like the preview feature you used in:
http://blueimp.github.io/jQuery-File-Upload/

I also find that for iPhone 4s, the test demo works for images from screenshot (does not work for images from camera), so I guess the problem has something to do with processing exif data in ios.

Thanks,
Sidney

[blueimp]

Hi @zengxinzhy,

I can confirm that on your demo, loading images and adding them as canvas to the body does indeed fail on iPhone 4s.

However, selecting and displaying images as canvas works on iPhone 4s on the demo, which also sets the canvas option to true by default:
https://github.com/blueimp/JavaScript-Load-Image/blob/master/js/demo.js#L79
The demo works with images independently of the image source - camera or screenshot - and does display EXIF data as well.

So I'm sorry I'm not sure what is wrong with your specific demo, especially since it's quite a simple one.
You could try setting a size constraint, as it might very well be a simple memory constraint, as photos taken with the camera are quite large, and drawing them as canvas in the original size could exceed the memory available for the browser process.

[zengxinzhy]

Yes . After setting a maxWidth constraint, the problem is solved.

Thanks a lot for helping me figure out the issue