shoot I thought this was handled. I'll add this to the 5.0.1 release which is a patch coming out soon

Thanks!

@ericdrowell is this issuce still open. Since you clain it is fixed in 5.0.1 and now 5.1.0 is released?

The problem is still there. Actually, 5.1.0 is worse, not just the cashed image, the quality of non-cached shape is bad too.

Set the pixelRatio to 1 for desktops is really bad. It made everything blur in high resolution computers, like Mac Book Pro with Retina display. Here is the comments:

    As of 02/26/2014, there doesn't seem to be a way
    // to reliably calculate the browser zoom for modern browsers, which is why we just set
    // the pixel ratio to 1 for desktops

I don't know why you care browser zoom? Browser zoom wouldn't matter, it apply after the canvas drawing.

Are you sure that quality of non-cached shapes is bad? Everything is good for me. (tested on iPad)

I have the same problem. The quality is very bad. The the worst quality is when I downscale an image.

100% sure.
Here is the image in 5.1.0, left side is non-cached shape, right side is cached shape.
http://jsfiddle.net/kzhdev/43tfG/18/

This is the original in 5.0.1
http://jsfiddle.net/kzhdev/43tfG/8/

This is my fix:
http://jsfiddle.net/kzhdev/43tfG/17/

On iPad is OK because it was on mobile, its pixelRatio is 2. On desktop, like Mac Book with Retina display, the pixelRation is 1, that bad.