Move,rotate and scale UIImages, then merge them?

Question

Hi,guys

I apologize first ,because My English is no good. I will try my best to explain my problem.

I am building a photo app. You can choose images and move, rotate ,scale them. Finally, you can merge them to create a new image. I had no problem to display them on the screen, but when i wanted to merge them I encountered a problem.

Below is my code, i have not done scale yet, but i have done move and rotate. Rotation works correctly, but the location of the image is wrong.Who can help me, i will appreciate a lot!

enter code here

UIImage *newImage;

UIGraphicsBeginImageContext(CGSizeMake(320.0f,480.0f));
CGContextRef contextComponent = UIGraphicsGetCurrentContext();
for (UIImageView *subview in subviews) {
    if (subview.tag >= kBottleImageView || subview.tag == kPhotoView || subview.tag == kPhotoFrameImageView) {

        CGContextSaveGState(contextComponent);

        CGContextTranslateCTM(contextComponent, subview.center.x, (subview.bounds.size.height - subview.center.y));
        CGContextTranslateCTM(contextComponent, -subview.bounds.size.width/2, -subview.bounds.size.height/2);   

        if (subview.tag != kPhotoFrameImageView ) {
            if (subview.totalAngle != 0) { //totalAngle is the total rotated angle of the view 

                CGContextTranslateCTM (contextComponent, subview.bounds.size.width/2, subview.bounds.size.height/2);
                CGContextRotateCTM(contextComponent, (subview.totalAngle));
                CGContextTranslateCTM (contextComponent, -subview.bounds.size.width/2, -subview.bounds.size.height/2);
            }

        }

        [subview.image drawInRect:CGRectMake(0.0, 0.0, subview.bounds.size.width, subview.bounds.size.height)];

        CGContextRestoreGState(contextComponent);

    }
}   
newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();