iPhone : How in set alpha in UIImage on Touches with PIxel?

Question

- (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{


    NSSet *allTouches = [[event allTouches] retain];
    switch ([allTouches count])
    {
           case 1: {
           UITouch *touch = [[allTouches allObjects] objectAtIndex:0];
           CGPoint touchPoint =  [touch locationInView:[self view]];
                if(touchPoint.x > rightleg.frame.origin.x && touchPoint.x < rightleg.frame.origin.x + rightleg.frame.size.width &&
                   touchPoint.y > rightleg.frame.origin.y && touchPoint.y < rightleg.frame.origin.y + rightleg.frame.size.height ){
                   rightleg.alpha = rightleg.alpha + 0.005;
                }
            }
        case 2 :{
            UITouch *touch = [[allTouches allObjects] objectAtIndex:0];
            CGPoint touchPoint =  [touch locationInView:[self view]];
            if(touchPoint.x > leftleg.frame.origin.x && touchPoint.x < leftleg.frame.origin.x + leftleg.frame.size.width &&
               touchPoint.y > leftleg.frame.origin.y && touchPoint.y < leftleg.frame.origin.y + leftleg.frame.size.height ){
               leftleg.alpha = leftleg.alpha + 0.005;

            }
        }
    }


}

this code is set alpha on UIImage when user touches on Image, but How to set alpha on the pixel in UIImage when touches on that pixel ?

score 0 · Accepted Answer · edited May 23 '17 at 11:48

0

You would have to convert your UIImage to a bytes array, make the changes and then save to an UIImage again.

Something like this might help:

edited May 23 '17 at 11:48

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answered Jan 03 '12 at 12:22

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iPhone : How in set alpha in UIImage on Touches with PIxel?

1 Answers1