Open Radar

 
18-Jul-2010 10:21 AM Cyril Godefroy:
Summary:
Trying to edit and rewrite the IPTCDictionary with imageIO on the iPhone SDK 4.0.1 deletes the dictionary from the image. Seems only happening on jpeg files.

Steps to Reproduce:
---------------

Open a public.jpeg image with ImageIO

Read the ExifDictionary
read the GPSDictionary
Read the IPTCDictionary

Edit the info from these dictionaries

Rewrite the dictionaries to the file


Expected Results:
--------------

The end file should contain IPTC info, for example Keywords

Actual Results:
-----------
Preview on the Mac doesn't display any IPTC info, nor keywords


Notes:
------
I did try by putting a file with IPTC info in the shared document folder, editing it and saving it back: the destinationFile had no more IPTC Keywords.

Another developer had the same kind of issues, and reported on Stack Overflow:
http://stackoverflow.com/questions/3003036/

Here is the code, I also provide the full app.


- (void)saveMetaData{	
	CGImageSourceRef source = CGImageSourceCreateWithURL((CFURLRef)[NSURL fileURLWithPath:[self filePath]], nil);
	
	//get all the metadata in the image
    NSDictionary *metadata = (NSDictionary *) CGImageSourceCopyPropertiesAtIndex(source,0,NULL);
    
    //make the metadata dictionary mutable so we can add properties to it
    NSMutableDictionary *metadataAsMutable = [metadata mutableCopy];
    [metadata release];
	
	NSMutableDictionary *EXIFDictionary = [[[metadataAsMutable objectForKey:(NSString *)kCGImagePropertyExifDictionary]mutableCopy]autorelease];
    
    if(!EXIFDictionary)
    {
        //if the image does not have an EXIF dictionary (not all images do), then create one for us to use
        EXIFDictionary = [NSMutableDictionary dictionary];
    }
	
	//we need to format the date so it conforms to the EXIF spec and can be read by other apps
	
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
    
	//the date format for EXIF dates as from http://www.abmt.unibas.ch/dokumente/ExIF.pdf
    [dateFormatter setDateFormat:@"yyyy:MM:dd HH:mm:ss"]; 
    
	//use the date formatter to get a string from the date we were passed in the EXIF format
	NSString *EXIFFormattedCreatedDate = [dateFormatter stringFromDate:[self creationDate]]; 
    
	[dateFormatter release];
    
    [EXIFDictionary setObject:EXIFFormattedCreatedDate forKey:(NSString *)kCGImagePropertyExifDateTimeDigitized];
	
	NSMutableDictionary *GPSDictionary = [[[metadataAsMutable objectForKey:(NSString *)kCGImagePropertyGPSDictionary ]mutableCopy]autorelease];
	if(!GPSDictionary){

		GPSDictionary = [NSMutableDictionary dictionary];
	}
	[GPSDictionary setObject:self.longitude forKey:(NSString *)kCGImagePropertyGPSLongitude];
	[GPSDictionary setObject:self.latitude forKey:(NSString *)kCGImagePropertyGPSLatitude];
	
	
	NSMutableDictionary *IPTCDictionary = [[[metadataAsMutable objectForKey:(NSString *)kCGImagePropertyIPTCDictionary ]mutableCopy]autorelease];
	if(!IPTCDictionary){
		IPTCDictionary = [NSMutableDictionary dictionary];
	}
	if(self.name)
		[IPTCDictionary setObject:self.name forKey:(NSString *)kCGImagePropertyIPTCHeadline];
	if(self.tags)
		[IPTCDictionary setObject:self.tags forKey:(NSString *)kCGImagePropertyIPTCKeywords];
	
										  
	//add our modified dictionaries data back into the image’s metadata
    [metadataAsMutable setObject:EXIFDictionary forKey:(NSString *)kCGImagePropertyExifDictionary];
	[metadataAsMutable setObject:IPTCDictionary forKey:(NSString *)kCGImagePropertyIPTCDictionary];
    [metadataAsMutable setObject:GPSDictionary  forKey:(NSString *)kCGImagePropertyGPSDictionary];
	
    
    CFStringRef UTI = CGImageSourceGetType(source);
	//this will be the data CGImageDestinationRef will write into
    NSMutableData *data = [NSMutableData data];
    
    CGImageDestinationRef destination = CGImageDestinationCreateWithData((CFMutableDataRef)data,UTI,1,NULL);
    
    if(!destination)
    {
        NSLog(@"***Could not create image destination ***");
        return ;
    }
    
    //add the image contained in the image source to the destination, overidding the old metadata with our modified metadata
    CGImageDestinationAddImageFromSource(destination,source,0, (CFDictionaryRef) metadataAsMutable);
    
    //tell the destination to write the image data and metadata into our data object.
    //It will return false if something goes wrong
    BOOL success = NO;
    success = CGImageDestinationFinalize(destination);
    
    if(!success)
    {
        NSLog(@"***Could not create data from image destination ***");
        return ;
    }
    
    //now we have the data ready to go, so do whatever you want with it
    //here we just write it to disk at the same path we were passed
    [data writeToURL:[NSURL fileURLWithPath:[self filePath]] atomically:YES];
    
    //cleanup
    CFRelease(destination);
    CFRelease(source);
}


18-Jul-2010 10:25 AM Cyril Godefroy:
'Archive-1.zip' was successfully uploaded



-----------------
OpenRadar Note: Am I wrong in believing I should be able to write my iptc dict with this code? I have to admit, I'm an imageIO noob.