{"id":131,"date":"2006-06-08T21:41:30","date_gmt":"2006-06-09T02:41:30","guid":{"rendered":"http:\/\/bitpost.com\/news\/2006\/06\/08\/nice-png-alpha-blending-complements-of-the-gimp\/"},"modified":"2011-04-06T19:31:39","modified_gmt":"2011-04-07T00:31:39","slug":"nice-png-alpha-blending-complements-of-the-gimp","status":"publish","type":"post","link":"https:\/\/bitpost.com\/news\/2006\/nice-png-alpha-blending-complements-of-the-gimp\/","title":{"rendered":"Nice PNG alpha-blending complements of the Gimp"},"content":{"rendered":"

The PNG format is nice because it’s supported by Firefox and it has real alpha-based transparency. This looks great no matter WHAT color your background is:<\/p>\n

<\/div>\n

I have been working on improving the alpha on the category images here, specifically the MythTV and Linux-projects category images. Here’s how to get nice anti-aliased alpha-blended edges on PNG images in the Gimp.<\/p>\n

    \n
  1. Make sure you are using a PNG format, and you set Image->Mode to RGB.<\/li>\n
  2. If the PNG image doesn’t yet have an alpha layer, add one with Layer->Transparency->AddAlphaChannel.<\/li>\n
  3. Typically, you have an image with white where you want transparency, or an edge that used to be white and was sloppily converted to transparent along a hard edge. You want to select the white and\/or transparent areas, and let them cut into the rest of the image by a pixel or two. Use the magic wand selector, holding down Shift to gradually add to the selection, until you’ve got what you want. If it’s helpful, use Select->Grow and increase what you have selected by a pixel or two, once you get close.<\/li>\n
  4. Convert the white in the selection into alpha-blended anti-aliased transparency via either Layer->Transparency->ColorToAlpha or Colors->ColorToAlpha (they appear to be the same command).<\/li>\n<\/ol>\n

    This does a really nice job in a lot of cases (especially if you’ve got a clean starting image). Don’t forget about my image scraper<\/a>, to help you see what’s out there already – but I know you can do even better, whoop! I know this is bad of me… but I’m actually getting off on the fact that it looks awesome in Firefox and like a$$ in IE. Suck it M$. Oops did I say that out loud…<\/p>\n","protected":false},"excerpt":{"rendered":"

    The PNG format is nice because it’s supported by Firefox and it has real alpha-based transparency. This looks great no matter WHAT color your background is: I have been working on improving the alpha on the category images here, specifically the MythTV and Linux-projects category images. Here’s how<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"enabled":false},"version":2}},"categories":[10],"tags":[82],"class_list":["post-131","post","type-post","status-publish","format-standard","hentry","category-tricks-tips-tools","tag-gimp"],"aioseo_notices":[],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p9M11L-27","jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/posts\/131","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/comments?post=131"}],"version-history":[{"count":1,"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/posts\/131\/revisions"}],"predecessor-version":[{"id":1180,"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/posts\/131\/revisions\/1180"}],"wp:attachment":[{"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/media?parent=131"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/categories?post=131"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bitpost.com\/news\/wp-json\/wp\/v2\/tags?post=131"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}