Question

I don’t know whether it sounds silly,

I have an image which will be added in the UIImageView or an UIButton. That image contains some texts in the Red color and the background is black. Is it possible to change the BG color as well as the Text color to custom color. Is that possible ??

Answer 1

If, after considering George’s answer, you still need to modify the colours, you could try using Core Image filters.

The following example adjusts the hue of a UIImageView called screenImage by an angle given in angle.

- (void)rebuildFilterChain:(double)angle {
  UIImage *uiImage = [UIImage imageNamed:@"background.jpg"];
  CIImage *image = [CIImage imageWithCGImage:[uiImage CGImage]];

  CIFilter *hueAdjust = [CIFilter filterWithName:@"CIHueAdjust"];
  [hueAdjust setDefaults];
  [hueAdjust setValue:image forKey: @"inputImage"];
  [hueAdjust setValue: [NSNumber numberWithFloat:angle] forKey: @"inputAngle"];
  self.resultImage = [hueAdjust valueForKey: @"outputImage"];

  CGImageRef cgImage = [context createCGImage:resultImage fromRect:resultImage.extent];
  screenImage.image = [UIImage imageWithCGImage:cgImage];
  CGImageRelease(cgImage);
}

The full list of Core Image filters is on the Apple site.