Hi Justyn, On Wed, Sep 24, 2008 at 8:43 AM, Justyn Butler <[EMAIL PROTECTED]> wrote: > Hi, > > I've been searching for the answer to this but I'm stumped. Maybe it's > so obvious that there's no need for it to be covered in the docs, or > perhaps I just don't know the correct terminology to search for. > > If I have a png (like a button or logo) with anti-aliasing around the > edge and an alpha channel and I need to convert it to a gif, I can use > the semi-flatten option under Layer->Transparency. > This will remove any semi-transparency while conserving anti-aliasing > and the full-transparency of the image. > To use this filter you have to know what color background will be > behind the image when it is placed on the page. > > With the semi-flatten tool you can only provide a solid color that the > image will be placed over. > Normally this works fine, but I have a situation where the background > behind the gif fades from light to dark and consequently > semi-flattening against a solid color is not sufficient. > > So what I want to do is semi-flatten against my known background image > (a gradient, rather than a solid color) whilst preserving the > fully-transparent parts of the gif. > > I am very inexperienced with image software but I'm sure there must be > a better way than I am doing right now, which is: > > 1) png with alpha channel in top layer > 2) known background image in bottom layer > 3) select non-fully-transparent part of image with Select By Color > Tool (select alpha pixel then invert selection) > 4) Flatten image > 5) Copy selection > 6) Paste As New > > (Alpha to selection doesn't do the trick for step 3 because it > discounts some semi-transparent pixels as well as transparent ones.) I recommend:
1) Layer->Transparency->Threshold Alpha (to 1) 2) Alpha to selection 3) Copy Visible 4) Paste as New David -- Everything has reasons. Nothing has justification. Ĉio havas kialojn; Neniaĵo havas pravigeron. _______________________________________________ Gimp-user mailing list [email protected] https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
