I was recently working on some images of a mobile phone, where the mobile phone was surrounded by a solid color that I wanted to make transparent. Unfortunately the phone was black, and that color was dark gray, so when I made the dark gray a transparent color in Gimp using my usual approach — clicking Colors > Color to Alpha, then choosing dark gray — it had the effect of bleeding a lot of color out of the black phone. This was wrong.
I recently needed to make an icon look like an iOS style app icon -- a rounded rectangle with transparent corners -- and to do that I needed to learn how to create a rounded rectangle in Gimp. This tutorial contains a short step-by-step description of how to do this.
Note: I’m writing this tutorial in April, 2015, using Gimp 2.8.
Summary: How to make a Java JFrame transparent (translucent) on Mac OS X.
A lot of people complain about a lot of things in regards to Java on Apple's Mac OS X platform, and okay, occasionally I'm one of them, but a very cool thing you can do on OS X is to create translucent (transparent) frames and windows with Java.
Earlier today I wrote a blog entry about how to create a transparent/translucent JFrame on a Mac OS X system, and then I thought, "Wouldn't it be cool if you could dynamically control the transparency level of the frame?" I did a little bit of research to make sure this can be done, and sure enough, it can.