On 12/5/2009 13:24, Franz Buchinger wrote: > Gears introduced the concept of an "offscreen canvas" that doesn't draw > anything in the browser window, but can be used to manipulate images in a > web worker. > > I used this functionality to implement a "resize-before-upload" feature in > my photo gallery uploader. Now I'm trying to port my uploader to HTML5 but > there seems no way to delegate the scaling work to a HTML5 web worker. > Surely I could use the DOM canvas to scale down the photos in the main > "browser thread", but this means that the UI gets blocked during this > process. > > If the user chooses more than a few multi-megapixel photos, the > CPU-intensive downscaling will likely freeze the browser and trigger a > script abortion warning. > > Are there plans to introduce an "offscreen canvas" in html5? If not, which > workarounds are possible? > Hi Franz,
ImageData is cloneable via postMessage(), so you could perform some forms of image processing that way. --sigbjorn <s...@opera.com>
