On 24-01-12 15:31, Ivan Louette wrote:
Thanks ! I was not aware of that ! But then the Save Cairo png format should take account of the background color and this isn't the case.
True. Actually, I'm not sure why we have that format (I think I remember that it came up before on the mailing list, but I forgot the reason for its existence).
On the other hand if you have for example a semi-transparent red background color you cannot export an opaque bitmap with a background color which matches the tint of the semi-transparent red. You must open your png image in Gimp and remove alpha channel there. My proposal remove this additional step.
My point is, if you want the SVG to have a semi-transparent red background, why shouldn't the PNG? If you want an easy method to change a semitransparent background to an opaque background with the same look (assuming that the background is drawn over a white "backbackground"), why not create a button/extension to do that, why link it to bitmap export?
However that doesn't solve the question for "Make bitmap copy" which never take account of the background or the unselected objects in the area.
There are no reasons to treat differently "Export bitmap" and "Make bitmap copy" (or the "Copy to clipboard I add to the possibilities in my mockup).
Indeed, and "not taking into account the background" is exactly that behaviour. Basically "export to bitmap" gives you a bitmap version of the entire drawing, while "make bitmap copy" gives you a bitmap version of some object (which naturally does not contain a background).
I'm not saying that your proposal is a bad idea (in fact, I quite like the idea of consolidating these different features), just trying to understand why you wish to do something special with the alpha channel.