Ian Hickson wrote:
For another example, consider an algorithm that wants to reduce the size of
the image by 1px horizontally (e.g. content-aware image resizing as demoed
using canvas at
<http://labs.pimsworld.org/wp-content/uploads/2009/04/demo-content-aware-image-resizing-2/>).
If we're shrinking by one device pixel, then suddenly we can't even create a
canvas of the right size for the new image, because canvas size is specified
in integer CSS pixels. Note that the algorithm used here, basically
off-the-shelf, would in fact want to work on device pixels the way the spec is
written right now; in general it would want to work on whatever pixels
imagedata is in.
If you want to shrink an image, redraw it using drawImage() with different
dimensions.
You apparently didn't look at the linked-to page. It's basically
applying a graphical filter to an image that results in a smaller image.
It's explicitly NOT trying to resize the image using whatever
algorithm the browser happens to implement; it's implementing its own
image-resizing algorithm (one that arguably produces much better results
at the cost of a lot more computation).
I don't know what we can do about it either, though.
I'll think about this some more... I'm not too hopeful, though. :(
Especially for that image-resizing case, where we basically need to be
able to create a canvas with fractional CSS pixel dimensions or something.
-Boris
