// Assumes myImage is the PNG you are converting using (var b = new Bitmap(myImage.Width, myImage.Height)) { b.SetResolution(myImage.HorizontalResolution, myImage.VerticalResolution); using (var g = Graphics.FromImage(b)) { g.Clear(Color.White); g.DrawImageUnscaled(myImage, 0, 0); } // Now save b as a JPEG like you normally would }
-background white -alpha remove -alpha off Example: convert image.png -background white -alpha remove -alpha off white.png Feel free to replace white with any other color you want. Imagemagick documentation says this about the -alpha remove operation: This operation is simple and fast, and does the job without needing any extra memory use, or other side … Read more
No, there’s a lot more to it. Icons have a pretty elaborate internal structure, optimized to work reasonably on 1980s hardware. An icon image has three bitmaps, one for the icon, a monochrome bitmap that indicates what parts of the image are transparent and another monochrome bitmap that indicates what parts are reversed. Generating those … Read more
It is pretty unclear, there’s a lot you didn’t say. The biggest issue with transparency is that you can’t see it. You skipped a couple of steps, you didn’t explicitly specify the pixel format of your new bitmap, you didn’t initialize it at all and you didn’t say what output format you use. Some don’t … Read more
-background white -alpha remove -alpha off Example: convert image.png -background white -alpha remove -alpha off white.png Feel free to replace white with any other color you want. Imagemagick documentation says this about the -alpha remove operation: This operation is simple and fast, and does the job without needing any extra memory use, or other side … Read more
You may use rgba(). div#foo { background: rgba(0, 0, 255, 0.3); } To make it work in old Internet Explorers use CSS PIE. There are some limitations, but those are handled in a backwards compatible way: the RGB value will be rendered correctly and the opacity will be ignored.
This was puzzling to me, so I went to google, and ended up learning something new (after working around some vagaries in their examples). Apparently what you are doing is drawing many rectangles on top of each other, effectively nullifying the semi-transparency you want. So, the only ways to overcome this are to hard-code the … Read more