问题
I would like to have a feature in my app that
-lets you take a picture of yourself or other that has a fame eg "Wanted:" overlaid on it.
-The user then would take the photo and the overlay and photo would be combined into one
-The resulting image usable in code.
Any ideas where to/how to start with this. Any tutorials etc.
Cheers
回答1:
It can get a little tricky, dealing with the transform applied to the preview of the image which makes it look a little different from the one you get handed by the camera, but here is the basic idea:
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
UIImage *img = [info objectForKey:UIImagePickerControllerOriginalImage];
// Here we are throwing away lots of image resolution -- but since our art is built for the 320 x 480 screen
// and we are worried about uploading bandwidth, crunching the image down from ~1600 x 2400 to 320 x 480 just makes sense
// note that the proportion is a little different, so the picture is slightly stretched in the y-axis, but this is augmented reality, so we like that
// note that hardwareScreenSize has to be determined by checking UIDeviceHardware
UIGraphicsBeginImageContext(hardwareScreenSize);
[img drawInRect:CGRectMake(0, ((hardwareScreenSize.height - hardwareScreenSize.height ) / 2), hardwareScreenSize.width, hardwareScreenSize.height)];
// this scales overlayImage to fit ontop of camera image
[(UIImage *)overlayImage drawInRect:CGRectMake(0, 0, hardwareScreenSize.width, hardwareScreenSize.height)];
UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();
[finalImage retain];
UIGraphicsEndImageContext();
来源：https://stackoverflow.com/questions/4363402/overlaying-a-frame-on-the-camera-view-and-then-saving-and-using-the-resulting-ph