Real-time watermark image on iphone camera screen

Question

Special thanks in advance ...... I m beggininer in iphone software development.

Just find how to programmatically add a real-time image to the camera using cocoa. Not looking step by step (although that would be wonderful), but more or less looking for where I should start looking, how to learn. Are there frameworks designed for this? I would like to see something native to objective-C using the Xcode infrastructure, because I would like to give it to the iPhone in the end. Any help would be great.

Answer 1

UPDATE: here is my other answer about how this overlay view can be placed under the camera animation: view camera overlay - just for preview?

Helo Rajendra!

I created a simple iPhone OS application for Windows to give you a very simple example of what and how to do, to take pictures with the camera, view overlays in camera mode, resize and merge images. On this project, in fact, there is only the header and AppDelegate implementation files, and they can be easily played back in Xcode.

Here's the header file:

//
//  CameraWatermarkAppDelegate.h
//  CameraWatermark
//
//  Created by Ivan Karpan on 1/16/10.
//  Copyright __MyCompanyName__ 2010. All rights reserved.
//

#import <UIKit/UIKit.h>


@interface CameraWatermarkAppDelegate : NSObject < UIApplicationDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate > {
    UIImageView *imageView;
    UIViewController *viewController;
    UIWindow *window;
}

@property (nonatomic, retain) UIImageView *imageView;
@property (nonatomic, retain) UIViewController *viewController;
@property (nonatomic, retain) IBOutlet UIWindow *window;


@end

And here is the implementation file:

//
//  CameraWatermarkAppDelegate.m
//  CameraWatermark
//
//  Created by Ivan Karpan on 1/16/10.
//  Copyright __MyCompanyName__ 2010. All rights reserved.
//

#import "CameraWatermarkAppDelegate.h"


const float WATERMARK_ALPHA = 0.5;


@implementation CameraWatermarkAppDelegate

@synthesize imageView, viewController, window;


- (void)applicationDidFinishLaunching:(UIApplication *)application {
    self.viewController = [[UIViewController new] autorelease];
    viewController.view.backgroundColor = [UIColor blackColor];

    // An image view to save to (and therefore display) the captured image
    self.imageView = [[UIImageView new] autorelease];
    imageView.frame = viewController.view.frame;
    [viewController.view addSubview:imageView];

    [window addSubview:viewController.view];

    UIImagePickerController *anImagePickerController = [UIImagePickerController new];
    anImagePickerController.delegate = self;
    anImagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera;

    {// This block of code is only needed in case you want your watermark to be displayed also during the shooting process
        UIImageView *anImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"Watermark.png"]];
        anImageView.alpha = WATERMARK_ALPHA;
        anImageView.contentMode = UIViewContentModeTopLeft;
        anImageView.frame = viewController.view.frame;
        anImagePickerController.cameraOverlayView = anImageView;
        [anImageView release];
    }

    // From the very beginning we simply present the image picker controller
    [viewController presentModalViewController:anImagePickerController animated:NO];
    [anImagePickerController release];
}


- (void)dealloc {
    [imageView release];
    [viewController release];
    [window release];
    [super dealloc];
}

#pragma mark UIImagePickerControllerDelegate

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    UIGraphicsBeginImageContext(CGSizeMake(320, 480));
    // This is where we resize captured image
    [(UIImage *)[info objectForKey:UIImagePickerControllerOriginalImage] drawInRect:CGRectMake(0, 0, 320, 480)];
    // And add the watermark on top of it
    [[UIImage imageNamed:@"Watermark.png"] drawAtPoint:CGPointMake(0, 0) blendMode:kCGBlendModeNormal alpha:WATERMARK_ALPHA];
    // Save the results directly to the image view property
    imageView.image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    // Dismiss the image picker controller and look at the results
    [picker dismissModalViewControllerAnimated:YES];
}


@end

I hope this serves as a starting point.