Decoding JPEG 2000 files to UIImage

UIImage+JPEG2000.h

#import <Foundation/Foundation.h>

extern UIImage * UIImageWithJPEG2000Data( NSData * data ) ;

UIImage+JPEG2000.m

#import "UIImage+JPEG2000.h"
#import <objc/runtime.h>

#import "openjpeg.h"

static UIImage * UIImageWithJPEG2000File( id self, SEL selector, NSString * name ) ;

@implementation NSObject (UIImage_JPEG2000)

static UIImage * (*old_UIImage_imageNamed)(id target, SEL selector, NSString * name ) = NULL ;

+(void)load
{	
	NSAutoreleasePool * pool = [[ NSAutoreleasePool alloc ] init ] ;

	Method m = class_getClassMethod( [ UIImage class ], @selector( imageNamed: )) ;
	old_UIImage_imageNamed = (UIImage *(*)(id, SEL, NSString*))method_setImplementation( m, (IMP)UIImageWithJPEG2000File ) ;
	DebugAssert( old_UIImage_imageNamed ) ;	
	
	[ pool release ] ;
}

@end

static CGImageRef CGImageCreateWithJPEG2000Image( opj_image_t * image )
{
	long w = image->comps[0].w ;
	long h = image->comps[0].h ;
	DebugAssert( w > 0 && h > 0 ) ;

	CGColorSpaceRef cs = NULL ;
	BOOL hasAlpha = NO ;
	
	if ( image->numcomps == 1 )
	{
		cs = CGColorSpaceCreateDeviceGray() ;
	}
	else
	{
		// only support 3 (RGB) or 4 (RGBA) component images
		DebugAssert( image->numcomps == 3 || image->numcomps == 4 ) ;
		
		hasAlpha = image->numcomps == 4 ;
		cs = CGColorSpaceCreateDeviceRGB() ;
	}
	DebugAssert( cs ) ;
	
	for( int index=0; index < image->numcomps; ++index )
	{
		DebugAssert( image->comps[ index ].prec == 8 &&
					w == image->comps[index].w 
					&& h == image->comps[index].h ) ;
	}

	size_t bitmapNumBytes = w * h * 4;//image->numcomps ;
	CFMutableDataRef bitmapCFData = CFDataCreateMutable( kCFAllocatorDefault, 0 ) ;
	CFDataSetLength( bitmapCFData, bitmapNumBytes ) ;
	
	DebugAssert( bitmapCFData ) ;
	CGBitmapInfo bitmapInfo = kCGBitmapByteOrder32Big ;
	
	if ( image->numcomps == 1 )
	{
		uint8_t * p = (uint8_t*)CFDataGetMutableBytePtr( bitmapCFData ) ;
		uint32_t * s = (uint32_t*)image->comps[0].data ;
		
		for( int index=0, count = w * h; index < count; ++index )
		{
			*p = *s ;
			++p ;
			++s ;
			
		}
	}
	else
	{
		uint8_t * p = (uint8_t*)CFDataGetMutableBytePtr( bitmapCFData ) ;

		uint32_t * r = (uint32_t *)image->comps[0].data ;
		uint32_t * g = (uint32_t *)image->comps[1].data ;
		uint32_t * b = (uint32_t *)image->comps[2].data ;

		if ( hasAlpha )
		{
			bitmapInfo |= kCGImageAlphaPremultipliedLast ;
			uint32_t * a = (uint32_t *)image->comps[3].data ;
			
			for( int index=0, count = w * h; index < count; ++index )
			{
				*p++ = *r++ ;
				*p++ = *g++ ;
				*p++ = *b++ ;
				*p++ = *a++ ;				
			}
			
		}
		else
		{
			bitmapInfo |= kCGImageAlphaNoneSkipLast ;
			for( int index=0, count = w * h; index < count; ++index )
			{
				*p++ = *r++ ;
				*p++ = *g++ ;
				*p++ = *b++ ;
				*p++ = 0xFF ;
			}
		}
	}
	
	CGDataProviderRef dataProvider = CGDataProviderCreateWithCFData( bitmapCFData ) ;
	if ( bitmapCFData ) { CFRelease( bitmapCFData ) ; }
	
	DebugAssert( dataProvider ) ;
			
	int bpc = image->comps[0].prec ;	// bits per component
	int bpp = image->numcomps == 1 ? bpc : (4 * bpc) ;		// bits per pixel
	int bpr = bpp * w / 8 ;				// bytes per row
	
	CGImageRef cgImage = CGImageCreate(w, h, bpc, bpp, bpr, cs, bitmapInfo, dataProvider, NULL, false, kCGRenderingIntentDefault ) ;

	CGDataProviderRelease( dataProvider ) ;
	CGColorSpaceRelease( cs ) ;
	
	DebugAssert( cgImage ) ;
	
	return cgImage ;
}

UIImage * UIImageWithJPEG2000Data( NSData * data )
{
	if ( data.length == 0 )
	{
		DebugLog(@"%s data is empty\n", __PRETTY_FUNCTION__ ) ;
		return nil ;
	}

	opj_dinfo_t * decompressor = opj_create_decompress(CODEC_JP2) ;	// CODEC_JP2? Just a guess.
	DebugAssert( decompressor ) ;
	
	opj_dparameters_t params ;
	opj_set_default_decoder_parameters( & params );
	
	opj_setup_decoder( decompressor, & params ) ;

	opj_cio_t * cio = opj_cio_open( (opj_common_struct_t*)decompressor, (unsigned char *)data.bytes, data.length ) ;
	DebugAssert( cio ) ;
	
//	opj_set_event_mgr( (opj_common_ptr)decompressor, & (opj_event_mgr_t){ error_handler, warning_handler, info_handler }, NULL ) ;
	
	opj_image_t * image = opj_decode( decompressor, cio ) ;
	
	CGImageRef cgImage = nil ;
	if ( image )
	{
		cgImage = CGImageCreateWithJPEG2000Image( image ) ;
	
		opj_image_destroy( image ) ;
	}
	opj_cio_close( cio ) ;
	opj_destroy_decompress( decompressor ) ;
	
	if ( !cgImage )
	{
		return nil ;
	}

	UIImage * result = [ UIImage imageWithCGImage:cgImage ]  ;
	CGImageRelease( cgImage ) ;
	
	return result ;
}

static UIImage * UIImageWithJPEG2000File( id self, SEL selector, NSString * name )
{
	UIImage * result = (*old_UIImage_imageNamed)( self, selector, name ) ;
	
	if ( !result )
	{
		NSError * error = nil ;
		NSString * baseName = [ name stringByDeletingPathExtension ] ;
		NSString * extension = [ name pathExtension ] ;
		
		NSString * path = [ [ NSBundle mainBundle ] pathForResource:baseName ofType:extension ] ;
		if ( path )
		{
			NSData * data = [ NSData dataWithContentsOfFile:path options:NSDataReadingMapped error:&error ] ;
			DebugAssert( data ) ;
			
			result = UIImageWithJPEG2000Data( data ) ;
		}
	}
	
	return result ;
}

UIImageJPEG2000.m

#import "UIImage+JPEG2000.h"
#import <objc/runtime.h>

#import "openjpeg.h"

static UIImage * UIImageWithJPEG2000File( id self, SEL selector, NSString * name ) ;

@implementation NSObject (UIImage_JPEG2000)

static UIImage * (*old_UIImage_imageNamed)(id target, SEL selector, NSString * name ) = NULL ;

+(void)load
{	
	NSAutoreleasePool * pool = [[ NSAutoreleasePool alloc ] init ] ;

	Method m = class_getClassMethod( [ UIImage class ], @selector( imageNamed: )) ;
	old_UIImage_imageNamed = (UIImage *(*)(id, SEL, NSString*))method_setImplementation( m, (IMP)UIImageWithJPEG2000File ) ;
	DebugAssert( old_UIImage_imageNamed ) ;	
	
	[ pool release ] ;
}

@end

static CGImageRef CGImageCreateWithJPEG2000Image( opj_image_t * image )
{
	long w = image->comps[0].w ;
	long h = image->comps[0].h ;
	DebugAssert( w > 0 && h > 0 ) ;

	CGColorSpaceRef cs = NULL ;
	BOOL hasAlpha = NO ;
	
	if ( image->numcomps == 1 )
	{
		cs = CGColorSpaceCreateDeviceGray() ;
	}
	else
	{
		// only support 3 (RGB) or 4 (RGBA) component images
		DebugAssert( image->numcomps == 3 || image->numcomps == 4 ) ;
		
		hasAlpha = image->numcomps == 4 ;
		cs = CGColorSpaceCreateDeviceRGB() ;
	}
	DebugAssert( cs ) ;
	
	for( int index=0; index < image->numcomps; ++index )
	{
		DebugAssert( image->comps[ index ].prec == 8 &&
					w == image->comps[index].w 
					&& h == image->comps[index].h ) ;
	}

	size_t bitmapNumBytes = w * h * 4;//image->numcomps ;
	CFMutableDataRef bitmapCFData = CFDataCreateMutable( kCFAllocatorDefault, 0 ) ;
	CFDataSetLength( bitmapCFData, bitmapNumBytes ) ;
	
	DebugAssert( bitmapCFData ) ;
	CGBitmapInfo bitmapInfo = kCGBitmapByteOrder32Big ;
	
	if ( image->numcomps == 1 )
	{
		uint8_t * p = (uint8_t*)CFDataGetMutableBytePtr( bitmapCFData ) ;
		uint32_t * s = (uint32_t*)image->comps[0].data ;
		
		for( int index=0, count = w * h; index < count; ++index )
		{
			*p = *s ;
			++p ;
			++s ;
			
		}
	}
	else
	{
		uint8_t * p = (uint8_t*)CFDataGetMutableBytePtr( bitmapCFData ) ;

		uint32_t * r = (uint32_t *)image->comps[0].data ;
		uint32_t * g = (uint32_t *)image->comps[1].data ;
		uint32_t * b = (uint32_t *)image->comps[2].data ;

		if ( hasAlpha )
		{
			bitmapInfo |= kCGImageAlphaPremultipliedLast ;
			uint32_t * a = (uint32_t *)image->comps[3].data ;
			
			for( int index=0, count = w * h; index < count; ++index )
			{
				*p++ = *r++ ;
				*p++ = *g++ ;
				*p++ = *b++ ;
				*p++ = *a++ ;				
			}
			
		}
		else
		{
			bitmapInfo |= kCGImageAlphaNoneSkipLast ;
			for( int index=0, count = w * h; index < count; ++index )
			{
				*p++ = *r++ ;
				*p++ = *g++ ;
				*p++ = *b++ ;
				*p++ = 0xFF ;
			}
		}
	}
	
	CGDataProviderRef dataProvider = CGDataProviderCreateWithCFData( bitmapCFData ) ;
	if ( bitmapCFData ) { CFRelease( bitmapCFData ) ; }
	
	DebugAssert( dataProvider ) ;
			
	int bpc = image->comps[0].prec ;	// bits per component
	int bpp = image->numcomps == 1 ? bpc : (4 * bpc) ;		// bits per pixel
	int bpr = bpp * w / 8 ;				// bytes per row
	
	CGImageRef cgImage = CGImageCreate(w, h, bpc, bpp, bpr, cs, bitmapInfo, dataProvider, NULL, false, kCGRenderingIntentDefault ) ;

	CGDataProviderRelease( dataProvider ) ;
	CGColorSpaceRelease( cs ) ;
	
	DebugAssert( cgImage ) ;
	
	return cgImage ;
}

UIImage * UIImageWithJPEG2000Data( NSData * data )
{
	if ( data.length == 0 )
	{
		DebugLog(@"%s data is empty\n", __PRETTY_FUNCTION__ ) ;
		return nil ;
	}

	opj_dinfo_t * decompressor = opj_create_decompress(CODEC_JP2) ;	// CODEC_JP2? Just a guess.
	DebugAssert( decompressor ) ;
	
	opj_dparameters_t params ;
	opj_set_default_decoder_parameters( & params );
	
	opj_setup_decoder( decompressor, & params ) ;

	opj_cio_t * cio = opj_cio_open( (opj_common_struct_t*)decompressor, (unsigned char *)data.bytes, data.length ) ;
	DebugAssert( cio ) ;
	
//	opj_set_event_mgr( (opj_common_ptr)decompressor, & (opj_event_mgr_t){ error_handler, warning_handler, info_handler }, NULL ) ;
	
	opj_image_t * image = opj_decode( decompressor, cio ) ;
	
	CGImageRef cgImage = nil ;
	if ( image )
	{
		cgImage = CGImageCreateWithJPEG2000Image( image ) ;
	
		opj_image_destroy( image ) ;
	}
	opj_cio_close( cio ) ;
	opj_destroy_decompress( decompressor ) ;
	
	if ( !cgImage )
	{
		return nil ;
	}

	UIImage * result = [ UIImage imageWithCGImage:cgImage ]  ;
	CGImageRelease( cgImage ) ;
	
	return result ;
}

static UIImage * UIImageWithJPEG2000File( id self, SEL selector, NSString * name )
{
	UIImage * result = (*old_UIImage_imageNamed)( self, selector, name ) ;
	
	if ( !result )
	{
		NSError * error = nil ;
		NSString * baseName = [ name stringByDeletingPathExtension ] ;
		NSString * extension = [ name pathExtension ] ;
		
		NSString * path = [ [ NSBundle mainBundle ] pathForResource:baseName ofType:extension ] ;
		if ( path )
		{
			NSData * data = [ NSData dataWithContentsOfFile:path options:NSDataReadingMapped error:&error ] ;
			DebugAssert( data ) ;
			
			result = UIImageWithJPEG2000Data( data ) ;
		}
	}
	
	return result ;
}

Hey,
Sorry for that comment. Removed it now. That was completely my mistake! It works like a gem!! Apologies! Memory was loosing on my end, and instrument pointed it to your code :-)