CGImageAlphaInfo.noneSkipLast There is no alpha channel. Declarationcase noneSkipLast See AlsoConstantsCGImageAlphaInfo.firstCGImageAlphaInfo.lastCGImageAlphaInfo.noneCGImageAlphaInfo.noneSkipFirstCGImageAlphaInfo.alphaOnlyCGImageAlphaInfo.premultipliedFirstCGImageAlphaInfo.premultipliedLast