OCRDemoViewController.mm

//
//  OCRDemoViewController.m
//  OCRDemo
//
//  Created by Nolan Brown on 12/30/09.
//

#import "OCRDemoViewController.h"
#import "baseapi.h"
#include <math.h>
static inline double radians (double degrees) {return degrees * M_PI/180;}

@implementation OCRDemoViewController

@synthesize iv,label;


// The designated initializer. Override to perform setup that is required before the view is loaded.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
        // Custom initialization

    }
    return self;
}


- (void)didReceiveMemoryWarning {
	// Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];
	
	// Release any cached data, images, etc that aren't in use.
}

- (void)viewDidLoad {
	[super viewDidLoad];

	// Release any retained subviews of the main view.
	// e.g. self.myOutlet = nil;
}


- (void)dealloc {
	[iv release];
	iv = nil;
	[label release];
	label = nil;
    [super dealloc];

}


#pragma mark -
#pragma mark IBAction
- (IBAction) takePhoto:(id) sender
{
	imagePickerController = [[UIImagePickerController alloc] init];
    imagePickerController.delegate = self;
    imagePickerController.sourceType =  UIImagePickerControllerSourceTypeCamera;
	
	[self presentModalViewController:imagePickerController animated:YES];
}
- (IBAction) findPhoto:(id) sender
{
	imagePickerController = [[UIImagePickerController alloc] init];
    imagePickerController.delegate = self;
    imagePickerController.sourceType =  UIImagePickerControllerSourceTypePhotoLibrary;
	
	[self presentModalViewController:imagePickerController animated:YES];
}

#pragma mark -

- (NSString *) applicationDocumentsDirectory
{
	NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
	NSString *documentsDirectoryPath = [paths objectAtIndex:0];
	return documentsDirectoryPath;
}

#pragma mark -
#pragma mark Image Processsing
- (void) startTesseract
{
	//code from http://robertcarlsen.net/2009/12/06/ocr-on-iphone-demo-1043

	NSString *dataPath = [[self applicationDocumentsDirectory] stringByAppendingPathComponent:@"tessdata"];
	/*
	 Set up the data in the docs dir
	 want to copy the data to the documents folder if it doesn't already exist
	 */
	NSFileManager *fileManager = [NSFileManager defaultManager];
	// If the expected store doesn't exist, copy the default store.
	if (![fileManager fileExistsAtPath:dataPath]) {
		// get the path to the app bundle (with the tessdata dir)
		NSString *bundlePath = [[NSBundle mainBundle] bundlePath];
		NSString *tessdataPath = [bundlePath stringByAppendingPathComponent:@"tessdata"];
		if (tessdataPath) {
			[fileManager copyItemAtPath:tessdataPath toPath:dataPath error:NULL];
		}
	}
	
	NSString *dataPathWithSlash = [[self applicationDocumentsDirectory] stringByAppendingString:@"/"];
	setenv("TESSDATA_PREFIX", [dataPathWithSlash UTF8String], 1);
	
	// init the tesseract engine.
	tess = new TessBaseAPI();
	
	tess->SimpleInit([dataPath cStringUsingEncoding:NSUTF8StringEncoding],  // Path to tessdata-no ending /.
					 "eng",  // ISO 639-3 string or NULL.
					 false);
	
	
}

- (NSString *) ocrImage: (UIImage *) uiImage
{
	
	//code from http://robertcarlsen.net/2009/12/06/ocr-on-iphone-demo-1043
	
	CGSize imageSize = [uiImage size];
	double bytes_per_line	= CGImageGetBytesPerRow([uiImage CGImage]);
	double bytes_per_pixel	= CGImageGetBitsPerPixel([uiImage CGImage]) / 8.0;
	
	CFDataRef data = CGDataProviderCopyData(CGImageGetDataProvider([uiImage CGImage]));
	const UInt8 *imageData = CFDataGetBytePtr(data);
	
	// this could take a while. maybe needs to happen asynchronously.
	char* text = tess->TesseractRect(imageData,(int)bytes_per_pixel,(int)bytes_per_line, 0, 0,(int) imageSize.height,(int) imageSize.width);
	
	// Do something useful with the text!
	NSLog(@"Converted text: %@",[NSString stringWithCString:text encoding:NSUTF8StringEncoding]);

	return [NSString stringWithCString:text encoding:NSUTF8StringEncoding];
}


//http://www.iphonedevsdk.com/forum/iphone-sdk-development/7307-resizing-photo-new-uiimage.html#post33912
-(UIImage *)resizeImage:(UIImage *)image {
	
	CGImageRef imageRef = [image CGImage];
	CGImageAlphaInfo alphaInfo = CGImageGetAlphaInfo(imageRef);
	CGColorSpaceRef colorSpaceInfo = CGColorSpaceCreateDeviceRGB();
	
	if (alphaInfo == kCGImageAlphaNone)
		alphaInfo = kCGImageAlphaNoneSkipLast;
	
	int width, height;
	
	width = 640;//[image size].width;
	height = 640;//[image size].height;
	
	CGContextRef bitmap;
	
	if (image.imageOrientation == UIImageOrientationUp | image.imageOrientation == UIImageOrientationDown) {
		bitmap = CGBitmapContextCreate(NULL, width, height, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, alphaInfo);
		
	} else {
		bitmap = CGBitmapContextCreate(NULL, height, width, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, alphaInfo);
		
	}
	
	if (image.imageOrientation == UIImageOrientationLeft) {
		NSLog(@"image orientation left");
		CGContextRotateCTM (bitmap, radians(90));
		CGContextTranslateCTM (bitmap, 0, -height);
		
	} else if (image.imageOrientation == UIImageOrientationRight) {
		NSLog(@"image orientation right");
		CGContextRotateCTM (bitmap, radians(-90));
		CGContextTranslateCTM (bitmap, -width, 0);
		
	} else if (image.imageOrientation == UIImageOrientationUp) {
		NSLog(@"image orientation up");	
		
	} else if (image.imageOrientation == UIImageOrientationDown) {
		NSLog(@"image orientation down");	
		CGContextTranslateCTM (bitmap, width,height);
		CGContextRotateCTM (bitmap, radians(-180.));
		
	}
	
	CGContextDrawImage(bitmap, CGRectMake(0, 0, width, height), imageRef);
	CGImageRef ref = CGBitmapContextCreateImage(bitmap);
	UIImage *result = [UIImage imageWithCGImage:ref];
	
	CGContextRelease(bitmap);
	CGImageRelease(ref);
	
	return result;	
}


#pragma mark -
#pragma mark UIImagePickerControllerDelegate
- (void)imagePickerController:(UIImagePickerController *)picker 
		didFinishPickingImage:(UIImage *)image
				  editingInfo:(NSDictionary *)editingInfo
{
	
	// Dismiss the image selection, hide the picker and
	
	//show the image view with the picked image
	
	[picker dismissModalViewControllerAnimated:YES];
	UIImage *newImage = [self resizeImage:image];
	iv.image = newImage;
	NSString *text = [self ocrImage:newImage];
	label.text = text;
	
}

@end