Change the hue of an iOS image
I want to change the hue of an image using a slider. What I've done:
float slideValue = sldHueChange.value;
beginImage= [CIImage imageWithCGImage:imgBorder.image.CGImage];
context = [CIContext contextWithOptions:[NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES] forKey:kCIContextUseSoftwareRenderer]];
filter= [CIFilter filterWithName:@"CIHueAdjust"];
[filter setValue:beginImage forKey:kCIInputImageKey];
[filter setValue:[NSNumber numberWithFloat:slideValue] forKey:@"inputAngle" ];
CIImage *outputImage = [filter outputImage];
CGImageRef cgimg =[context createCGImage:outputImage fromRect:[outputImage extent]];
UIImage *newImg = [UIImage imageWithCGImage:cgimg];
[imgBorder setImage:newImg];
CGImageRelease(cgimg);
Works. But this is behind the scenes. I want to change the hue of an image very smoothly. If you have an idea for a sleek changer please share it. I really need it. Thanks in advance.
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2 answers
Now I am doing the following:
CGRect rect = CGRectMake(0, 0, selectedBorderForChangingHue.size.width, selectedBorderForChangingHue.size.height);
UIGraphicsBeginImageContext(rect.size);
CGContextRef context1 = UIGraphicsGetCurrentContext();
CGContextClipToMask(context1, rect, selectedBorderForChangingHue.CGImage);
CGContextSetFillColorWithColor(context1, [[UIColor colorWithHue:sldHueChange.value/255.0f saturation:1.0f brightness:1.0f alpha:1.0f] CGColor]);
CGContextFillRect(context1, rect);
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImage *flippedImage = [UIImage imageWithCGImage:img.CGImage scale:1.0 orientation: UIImageOrientationDownMirrored];
imgBorder.image = flippedImage;
and it works great for me. and it's very smooth.
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user1982396
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