Example of "CIMaskToAlpha" filter's usage.

gistfile1.m

  CIContext *context = [CIContext contextWithOptions:nil];
  UIImage *entryImage = [UIImage imageNamed:@"someImage.png"];
  CIImage *image = [CIImage imageWithCGImage:[entryImage CGImage]];
  CIFilter *filter = [CIFilter filterWithName:@"CIMaskToAlpha"];
  [filter setValue:image forKey:kCIInputImageKey];
  CIImage *result = [filter valueForKey:kCIOutputImageKey];
  CGImageRef cgImage = [context createCGImage:result fromRect:[result extent]];

  UIImage *newImage = [UIImage imageWithCGImage:cgImage scale:[entryImage scale] orientation:UIImageOrientationUp];

Thank You! Is a SuperGood Example 😄

Thank you, that was useful.
Here's a version in Swift using a slightly shorter syntax: https://gist.github.com/lukas2/9723e3b125e5eaf856848c5c015adca5