ie image incompatibility

[dyoo]

something's breaking on ie8 for the following program

`(define p (crop 330 180 80 100 (bitmap/url "http://www.bootstrapworld.org/images/girls.jpg")))

(define (ghost p) (color-list->bitmap (map (lambda (c) (make-color (color-red c) (color-green c) (color-blue c) 100)) (image->color-list p)) (image-width p) (image-height p)))

(scale 2 (overlay (ghost p) (bitmap/url "http://racket-lang.org/logo.png")))`

[schanzer]

In the runtime, color-list->bitmap and image->color-list rely on canvas.getImageData and putImageData, neither of which are supported by the ExCanvas library. I explored adding this back in 2010, but it would require a serverside component to do the image<->pixel bridging, and send the result back to ExCanvas. It's simply not worth it, and even if this feature appeared tomorrow it would be unusably slow to work through a list of pixels in the current compiler on IE8. Even on Chrome, which DOES support this and whose js engine 100x faster, this is unusable.

WONTFIX, close bug.