Re: JPEG Quality test

On 11/29/2010 06:03 PM, Jakob Nilsson-Ehle wrote:

> canvas(toDataURL.jpeg.alpha.html ):
> http://test.w3.org/html/tests/approved/canvas/toDataURL.jpeg.alpha.html
> canvas(toDataURL.jpeg.quality.basic.html ):
> http://test.w3.org/html/tests/approved/canvas/toDataURL.jpeg.quality.basic.html
> canvas(toDataURL.jpeg.quality.notnumber.html ):
> http://test.w3.org/html/tests/approved/canvas/toDataURL.jpeg.quality.notnumber.html
> canvas(toDataURL.jpeg.quality.outsiderange.html ):
> http://test.w3.org/html/tests/approved/canvas/toDataURL.jpeg.quality.outsiderange.html
>
> All those tests will automatically pass if the returned data from
> toDataURL("image/jpeg") does not contain the mime type image/jpeg.
> That seems like very odd behaviour, since it is the explicit jpeg
> encoding that is being tested. So my question, once again, is, what is
> the reason for that? Wouldn't it make more sense to fail a browser if
> it doesn't do the jpeg encoding?

Support for image/jpeg is not required by the specification; see [1]. 
Arguably the tests should ensure that the image is correctly returned in 
PNG format if JPEG is not supported. At present only [2] tests this.

[1] http://www.whatwg.org/specs/web-apps/current-work/#dom-canvas-todataurl
[2] 
http://philip.html5.org/tests/canvas/suite/tests/toDataURL.unrecognised.html

Received on Monday, 29 November 2010 17:14:24 UTC