How to change the skin color of face from the source image in ios?

Question

MY code: How to manage RGB value for differet shades of face,and how to apply? this code will change the color of face along with hair,but i want 1.only face to be colored excluding hair.

    -(void)changeSkinColorValue:(float)value WithImage:(UIImage*)needToModified
    {

        CGContextRef ctx;

        CGImageRef imageRef = needToModified.CGImage;
        NSUInteger width = CGImageGetWidth(imageRef);
        NSUInteger height = CGImageGetHeight(imageRef);
        CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
        //unsigned char *rawData = malloc(firstImageV.image.size.height * firstImageV.image.size.width * 10);

        CFMutableDataRef m_DataRef = CFDataCreateMutableCopy(0, 0,CGDataProviderCopyData(CGImageGetDataProvider(firstImageV.image.CGImage)));
        UInt8 *rawData = (UInt8 *) CFDataGetMutableBytePtr(m_DataRef);
        int length = CFDataGetLength(m_DataRef);
        NSUInteger bytesPerPixel = 4;
        NSUInteger bytesPerRow = bytesPerPixel * firstImageV.image.size.width;
        NSUInteger bitsPerComponent = 8;

                CGContextRef context1 = CGBitmapContextCreate(rawData, firstImageV.image.size.width, firstImageV.image.size.height, bitsPerComponent, bytesPerRow, colorSpace,                     kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
        CGColorSpaceRelease(colorSpace);

        CGContextDrawImage(context1, CGRectMake(0, 0, firstImageV.image.size.width, firstImageV.image.size.height), imageRef);

        NSLog(@"%d::%d",width,height);


       // for(int ii = 0 ; ii < 250   ; ii+=4)
        //{

            for(int ii = 0 ; ii < length ; ii+=4)
            {
            //NSLog(@"Raw data %s",rawData);

            int  R = rawData[ii];
            int G = rawData[ii+1];
            int B = rawData[ii+2];

            //        NSLog(@"%d   %d   %d", R, G, B);
            //if( ( (R>60)&&(R<237) ) || ((G>10)&&(G<120))||((B>4) && (B<120)))
                 //       if( ( (R>100)&&(R<186) ) || ((G>56)&&(G<130))||((B>30) && (B<120)))
                //        if( ( (R>188)&&(R<228) ) || ((G>123)&&(G<163))||((B>85) && (B<125)))
                       // if( ( (R>95)&&(R<260) ) || ((G>40)&&(G<210))||((B>20) && (B<170)))

                        //new code......

                if( ( (R>0)&&(R<260) ) || ((G>0)&&(G<210))||((B>0) && (B<170)))

                    {
                        rawData[ii+1]=R;//13;
                        rawData[ii+2]=G;//43;
                        rawData[ii+3]=value;//63
                    }
                }


        ctx = CGBitmapContextCreate(rawData,
                            CGImageGetWidth( imageRef ),
                            CGImageGetHeight( imageRef ),
                            8,
                            CGImageGetBytesPerRow( imageRef ),
                            CGImageGetColorSpace( imageRef ),
                            kCGImageAlphaPremultipliedLast );

        imageRef = CGBitmapContextCreateImage(ctx);
        UIImage* rawImage = [UIImage imageWithCGImage:imageRef];
        //UIImageView *ty=[[UIImageView alloc]initWithFrame:CGRectMake(100, 200, 400, 400)];
        //ty.image=rawImage;
        //[self.view addSubview:ty];
        [secondImageV setImage:rawImage];
        CGContextRelease(context1);
        CGContextRelease(ctx);  
        free(rawData);
    }

Answer 1

Try to use GPUImage Framework by Brad Larson:

https://github.com/BradLarson/GPUImage

This is very powerful framework for working with images.

Read this question:

GPUImage create a custom Filter that change selected colors

Hope it helps!