<canvas> JPEG quality

At Opera we're planning on adding support to <canvas> for JPEG as export  
format. To make the file size reasonable there needs to be a way to set  
the quality level of the JPEG. Wikipedia has a nice example of why that  


One simple solution to this which is reasonably consistent with the rest  
of the <canvas> API is to add a jpegQuality DOM attribute to the <canvas>  
element which takes an integer in the range 0-1 (similar to globalAlpha).  
The default value could maybe be 0.75 as that usually gives reasonable  
looking images with a much smaller size than 1.0.

This attribute only affects toDataURL() and only when the first argument  
is not omitted and case-insensitively matches "image/jpeg".

Anne van Kesteren

Received on Thursday, 5 June 2008 15:05:11 UTC