I want to be able to add a text comment to the metadata of a JPEG and be able to read it back from within an iphone app.
I thought this would be fairly simple as ios4 contains support for EXIF info. So I added metadata using a Windows tool called used AnalogExif and read it back from my app using:
NSData *jpeg = UIImageJPEGRepresentation(myUIImage,1.0);
CGImageSourceRef source = CGImageSourceCreateWithData((CFDataRef)jpeg, NULL);
NSDictionary *metadata = (NSDictionary *) CGImageSourceCopyPropertiesAtIndex(source,0,NULL);
NSMutableDictionary *metadataAsMutable = [[metadata mutableCopy]autorelease];
[metadata release];
NSMutableDictionary *EXIFDictionary = [[[metadataAsMutable objectForKey:(NSString *)kCGImagePropertyExifDictionary]
And that works...to a point :)
What I get back in the metadata dictionary is something like:
(gdb) po metadata
{
ColorModel = RGB;
Depth = 8;
Orientation = 1;
PixelHeight = 390;
PixelWidth = 380;
"{Exif}" = {
ColorSpace = 1;
PixelXDimension = 380;
PixelYDimension = 390;
};
"{JFIF}" = {
DensityUnit = 0;
JFIFVersion = (
1,
1
);
XDensity = 1;
YDensity = 1;
};
"{TIFF}" = {
Orientation = 1;
};
}
But thats all I can get! I've edited the JPEG file with every EXIF editor I can find (mostly PC ones I should say) and although they all say I have added JPEG comments and EXIF captions and keywords, none of that info seems to be available from the Apple SDK in my app.
Has anyone managed to set a text field in the metadata of a jpeg and manage to read it back from an iphone app?
I didn't want to use a third party library if at all possible
many thanks in advance
You're correct in thinking that iOS does support more metadata than what you're seeing. You probably lost the data when you created a UIImage and then converted it back to JPEG. Try NSData *jpeg = [NSData dataWithContentsOfFile:#"foo.jpg"] and you should see the EXIF.
Related
I am trying to write a prototype to prove that RAW conversion from one format to another is possible. I have to convert a Nikon's raw file which is of .NEF format to Canon's .CR2 format. With help of various posts I create the original image TIFF representation's BitmapImageRep and use this to write the output file which has a .CR2 extension.
It does work but only problem for me is, the input file is of 21.5 MB but the output am getting is of 144.4 MB. While using NSTIFFCompressionPackBits gives me 142.1 MB.
I want to understand what is happening, I have tried various compression enums available but with no success.
Please help me understanding it. This is the source code:
#interface NSImage(RawConversion)
- (void) saveAsCR2WithName:(NSString*) fileName;
#end
#implementation NSImage(RawConversion)
- (void) saveAsCR2WithName:(NSString*) fileName
{
// Cache the reduced image
NSData *imageData = [self TIFFRepresentation];
NSBitmapImageRep *imageRep = [NSBitmapImageRep imageRepWithData:imageData];
// http://www.cocoabuilder.com/archive/cocoa/151789-nsbitmapimagerep-compressed-tiff-large-files.html
NSDictionary *imageProps = [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithInt:NSTIFFCompressionJPEG],NSImageCompressionMethod,
[NSNumber numberWithFloat: 1.0], NSImageCompressionFactor,
nil];
imageData = [imageRep representationUsingType:NSTIFFFileType properties:imageProps];
[imageData writeToFile:fileName atomically:NO];
}
#end
How could I get the output file which is in CR2 format but almost around the size of the input file with little variation as required for a CR2 file?
Edit 1:
Done changes based on Peter's suggestion of using CGImageDestinationAddImageFromSource method, but still I am getting the same result. The input source NEF file size 21.5 MB but the destination file size after conversion 144.4 MB.
Please review the code:
-(void)saveAsCR2WithCGImageMethodUsingName:(NSString*)inDestinationfileName withSourceFile:(NSString*)inSourceFileName
{
CGImageSourceRef sourceFile = MyCreateCGImageSourceRefFromFile(inSourceFileName);
CGImageDestinationRef destinationFile = createCGImageDestinationRefFromFile(inDestinationfileName);
CGImageDestinationAddImageFromSource(destinationFile, sourceFile, 0, NULL);
//https://developer.apple.com/library/mac/#documentation/graphicsimaging/Conceptual/ImageIOGuide/ikpg_dest/ikpg_dest.html
CGImageDestinationFinalize(destinationFile);
}
CGImageSourceRef MyCreateCGImageSourceRefFromFile (NSString* path)
{
// Get the URL for the pathname passed to the function.
NSURL *url = [NSURL fileURLWithPath:path];
CGImageSourceRef myImageSource;
CFDictionaryRef myOptions = NULL;
CFStringRef myKeys[2];
CFTypeRef myValues[2];
// Set up options if you want them. The options here are for
// caching the image in a decoded form and for using floating-point
// values if the image format supports them.
myKeys[0] = kCGImageSourceShouldCache;
myValues[0] = (CFTypeRef)kCFBooleanTrue;
myKeys[1] = kCGImageSourceShouldAllowFloat;
myValues[1] = (CFTypeRef)kCFBooleanTrue;
// Create the dictionary
myOptions = CFDictionaryCreate(NULL, (const void **) myKeys,
(const void **) myValues, 2,
&kCFTypeDictionaryKeyCallBacks,
& kCFTypeDictionaryValueCallBacks);
// Create an image source from the URL.
myImageSource = CGImageSourceCreateWithURL((CFURLRef)url, myOptions);
CFRelease(myOptions);
// Make sure the image source exists before continuing
if (myImageSource == NULL){
fprintf(stderr, "Image source is NULL.");
return NULL;
}
return myImageSource;
}
CGImageDestinationRef createCGImageDestinationRefFromFile (NSString *path)
{
NSURL *url = [NSURL fileURLWithPath:path];
CGImageDestinationRef myImageDestination;
//https://developer.apple.com/library/mac/#documentation/graphicsimaging/Conceptual/ImageIOGuide/ikpg_dest/ikpg_dest.html
float compression = 1.0; // Lossless compression if available.
int orientation = 4; // Origin is at bottom, left.
CFStringRef myKeys[3];
CFTypeRef myValues[3];
CFDictionaryRef myOptions = NULL;
myKeys[0] = kCGImagePropertyOrientation;
myValues[0] = CFNumberCreate(NULL, kCFNumberIntType, &orientation);
myKeys[1] = kCGImagePropertyHasAlpha;
myValues[1] = kCFBooleanTrue;
myKeys[2] = kCGImageDestinationLossyCompressionQuality;
myValues[2] = CFNumberCreate(NULL, kCFNumberFloatType, &compression);
myOptions = CFDictionaryCreate( NULL, (const void **)myKeys, (const void **)myValues, 3,
&kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
//https://developer.apple.com/library/mac/#documentation/graphicsimaging/Conceptual/ImageIOGuide/imageio_basics/ikpg_basics.html#//apple_ref/doc/uid/TP40005462-CH216-SW3
CFStringRef destFileType = CFSTR("public.tiff");
// CFStringRef destFileType = kUTTypeJPEG;
CFArrayRef types = CGImageDestinationCopyTypeIdentifiers(); CFShow(types);
myImageDestination = CGImageDestinationCreateWithURL((CFURLRef)url, destFileType, 1, myOptions);
return myImageDestination;
}
Edit 2: Used the second approach told by #Peter. This gives interesting result. It's effect is the same as renaming the file in finder something like "example_image.NEF" to "example_image.CR2". Surprisingly what happens when converting both programmatically and in finder is, the source file which is 21.5 MB will turn out to be 59 KB. This is without any compression set in the code. Please see the code and suggest:
-(void)convertNEFWithTiffIntermediate:(NSString*)inNEFFile toCR2:(NSString*)inCR2File
{
NSData *fileData = [[NSData alloc] initWithContentsOfFile:inNEFFile];
if (fileData)
{
NSBitmapImageRep *imageRep = [NSBitmapImageRep imageRepWithData:fileData];
// [imageRep setCompression:NSTIFFCompressionNone
// factor:1.0];
NSDictionary *imageProps = nil;
NSData *destinationImageData = [imageRep representationUsingType:NSTIFFFileType properties:imageProps];
[destinationImageData writeToFile:inCR2File atomically:NO];
}
}
The first thing I would try doesn't involve NSImage or NSBitmapImageRep at all. Instead, I would create a CGImageSource for the source file and a CGImageDestination for the destination file, and use CGImageDestinationAddImageFromSource to transfer all of the images from A to B.
You're converting to TIFF twice in this code:
You create an NSImage, I assume from the source file.
You ask the NSImage for its TIFFRepresentation (TIFF conversion #1).
You create an NSBitmapImageRep from the first TIFF data.
You ask the NSBitmapImageRep to generate a second TIFF representation (TIFF conversion #2).
Consider creating an NSBitmapImageRep directly from the source data, and not using NSImage at all. You would then skip directly to step 4 to generate the output data.
(But I still would try CGImageDestinationAddImageFromSource first.)
Raw image files have their own (proprietary) representation.
For example, they may use 14-bit per component, and mosaic patterns, which are not supported by your code.
I think you should use a lower-level API and really reverse engineer the RAW format you are trying to save to.
I would start with DNG, which is relatively easy, as Adobe provides an SDK to write it.
I'm generating UIImages with a bit-bucket, creating them on the fly and swapping the UIImageView's image. Is there a way to edit the UIImageView's Image directly? (ie. change the color of a specific pixel, without removing the UIImage from the UIImageView, and get it to redraw.)
Currently, I'm flushing the UIImage and using imageWithCGIImage to make a new one, and assigning it to the UIImageView. This works. Shows no MemLeaks. But on the iPhone (3Gs) after about 100 image replacements, CRASHES. Cache'n issue? The memory summation seems to be hitting the phone's limit if cache not releasing, however, Simulator does not show memory consumption with each image swap. Stays flatlined without leaks.
Note: topologyImage array is the RGBA pixel-bucket. The REF variables are not released. Every attempt to do so, crashes next call. Without, Instruments reports no leaks.
=========
CGColorSpaceRef colorSpaceRef=CGColorSpaceCreateDeviceRGB();
CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault | kCGImageAlphaLast;
CGColorRenderingIntent renderingIntent=kCGRenderingIntentDefault;
CGDataProviderRef provider=CGDataProviderCreateWithData(NULL,topologyImage,(I*I*4),NULL);
CGImageRef imageRef=CGImageCreate(I,I,8,4*8,4*I,colorSpaceRef,bitmapInfo,provider,NULL,false,renderingIntent);
UIImage *img=[UIImage imageWithCGImage:imageRef];
if( IMG[NDXtopo].vw ) {
[IMG[NDXtopo].vw setImage:img];
}
else {
IMG[NDXtopo].vw=[[UIImageView alloc] initWithImage:img];
[master.view addSubview:IMG[NDXtopo].vw];
}
Basically you should release your references, especially the CGImageRef since the imageWithCGImage doesn't take ownership of the CGImage but rather seems to copy the data internally.
The docs on this are quite unclear, but from what I have found in my testing if I don't release CGImageRefs and CGDataProviderRefs it will eventually cause the application to get memory warnings... and then crash.
Not sure why you would have a crash, but in doing a quick test with:
UIImageView *view = [[UIImageView alloc] init];
int I = 128;
unsigned char *topologyImage = malloc(I*I*4*sizeof(unsigned char));
for(int i=0; i<I*I*4; i++)
{
topologyImage[i] = 100;
}
for(int i=0; i<1000; i++)
{
CGColorSpaceRef colorSpaceRef=CGColorSpaceCreateDeviceRGB();
CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault | kCGImageAlphaLast;
CGColorRenderingIntent renderingIntent=kCGRenderingIntentDefault;
CGDataProviderRef provider=CGDataProviderCreateWithData(NULL,topologyImage,(I*I*4),NULL);
CGImageRef imageRef=CGImageCreate(I,I,8,4*8,4*I,colorSpaceRef,bitmapInfo,provider,NULL,false,renderingIntent);
CGColorSpaceRelease(colorSpaceRef);
CGDataProviderRelease(provider);
UIImage *img=[UIImage imageWithCGImage:imageRef];
view.image = img;
CGImageRelease(imageRef);
}
free(topologyimage);
Seems to work just fine for me, so whatever is causing your crash seems to be because of something outside of your example, like for example how you got the image data into the topologyImage
in a cocoa application I'm currently coding, I'm getting snapshot images from a Quartz Composer renderer (NSImage objects) and I would like to encode them in a QTMovie in 720*480 size, 25 fps, and H264 codec using the addImage: method. Here is the corresponding piece of code:
qRenderer = [[QCRenderer alloc] initOffScreenWithSize:NSMakeSize(720,480) colorSpace:CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB) composition:[QCComposition compositionWithFile:qcPatchPath]]; // define an "offscreen" Quartz composition renderer with the right image size
imageAttrs = [NSDictionary dictionaryWithObjectsAndKeys: #"avc1", // use the H264 codec
QTAddImageCodecType, nil];
qtMovie = [[QTMovie alloc] initToWritableFile: outputVideoFile error:NULL]; // initialize the output QT movie object
long fps = 25;
frameNum = 0;
NSTimeInterval renderingTime = 0;
NSTimeInterval frameInc = (1./fps);
NSTimeInterval myMovieDuration = 70;
NSImage * myImage;
while (renderingTime <= myMovieDuration){
if(![qRenderer renderAtTime: renderingTime arguments:NULL])
NSLog(#"Rendering failed at time %.3fs", renderingTime);
myImage = [qRenderer snapshotImage];
[qtMovie addImage:myImage forDuration: QTMakeTimeWithTimeInterval(frameInc) withAttributes:imageAttrs];
[myImage release];
frameNum ++;
renderingTime = frameNum * frameInc;
}
[qtMovie updateMovieFile];
[qRenderer release];
[qtMovie release];
It works, however my application is not able to do that in real time on my new MacBook Pro, while I know that QuickTime Broadcaster can encode images in real time in H264 with an even higher quality that the one I use, on the same computer.
So why ? What's the issue here? Is this a hardware management issue (multi-core threading, GPU,...) or am I missing something? Let me preface that I'm new (2 weeks of practice) in the Apple development world, both in objective-C, cocoa, X-code, Quicktime and Quartz Composer libraries, etc.
Thanks for any help
AVFoundation is a more efficient way to render a QuartzComposer animation to an H.264 video stream.
size_t width = 640;
size_t height = 480;
const char *outputFile = "/tmp/Arabesque.mp4";
QCComposition *composition = [QCComposition compositionWithFile:#"/System/Library/Screen Savers/Arabesque.qtz"];
QCRenderer *renderer = [[QCRenderer alloc] initOffScreenWithSize:NSMakeSize(width, height)
colorSpace:CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB) composition:composition];
unlink(outputFile);
AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:[NSURL fileURLWithPath:#(outputFile)] fileType:AVFileTypeMPEG4 error:NULL];
NSDictionary *videoSettings = #{ AVVideoCodecKey : AVVideoCodecH264, AVVideoWidthKey : #(width), AVVideoHeightKey : #(height) };
AVAssetWriterInput* writerInput = [[AVAssetWriterInput alloc] initWithMediaType:AVMediaTypeVideo outputSettings:videoSettings];
[videoWriter addInput:writerInput];
[writerInput release];
AVAssetWriterInputPixelBufferAdaptor *pixelBufferAdaptor = [AVAssetWriterInputPixelBufferAdaptor assetWriterInputPixelBufferAdaptorWithAssetWriterInput:writerInput sourcePixelBufferAttributes:NULL];
int framesPerSecond = 30;
int totalDuration = 30;
int totalFrameCount = framesPerSecond * totalDuration;
[videoWriter startWriting];
[videoWriter startSessionAtSourceTime:kCMTimeZero];
__block long frameNumber = 0;
dispatch_queue_t workQueue = dispatch_queue_create("com.example.work-queue", DISPATCH_QUEUE_SERIAL);
NSLog(#"Starting.");
[writerInput requestMediaDataWhenReadyOnQueue:workQueue usingBlock:^{
while ([writerInput isReadyForMoreMediaData]) {
NSTimeInterval frameTime = (float)frameNumber / framesPerSecond;
if (![renderer renderAtTime:frameTime arguments:NULL]) {
NSLog(#"Rendering failed at time %.3fs", frameTime);
break;
}
CVPixelBufferRef frame = (CVPixelBufferRef)[renderer createSnapshotImageOfType:#"CVPixelBuffer"];
[pixelBufferAdaptor appendPixelBuffer:frame withPresentationTime:CMTimeMake(frameNumber, framesPerSecond)];
CFRelease(frame);
frameNumber++;
if (frameNumber >= totalFrameCount) {
[writerInput markAsFinished];
[videoWriter finishWriting];
[videoWriter release];
[renderer release];
NSLog(#"Rendered %ld frames.", frameNumber);
break;
}
}
}];
In my testing this is around twice as fast as your posted code that uses QTKit. The biggest improvement appears to come from the H.264 encoding being handed off to the GPU rather than being performed in software. From a quick glance at a profile it appears that the remaining bottlenecks are the rendering of the composition itself, and reading the rendered data back from the GPU in to a pixel buffer. Obviously the complexity of your composition will have some impact on this.
It may be possible to further optimize this by using QCRenderer's ability to provide snapshots as CVOpenGLBufferRefs, which may keep the frame's data on the GPU rather than reading it back to hand it off to the encoder. I didn't look too far in to that though.
I wish to search in the iphone AddressBook through my app using the number as the key and then retrieve the image associated to that contact and display it on the UIImageView.
I tried using ABAddressBook framework but was clueless to proceed.
Can anyone please suggest me the solutions or any alternative path that I can follow. Any code snippet would also be of great help!!
Any form of help would be highly appreciable.
Thanks in advance
The AB framework can be a real pain at times. But it breaks down to a series of pretty simple operations. First, you have to create an ABAddressBook instance:
ABAddressBookRef addressbook = ABAddressBookCreate();
Then you'll want to make a copy of the array of all people in the address book, and step through them looking for the data you want:
CFArrayRef allPeople = ABAddressBookCopyArrayOfAllPeople(addressbook);
CFIndex numPeople = ABAddressBookGetPersonCount(addressbook);
for (int i=0; i < numPeople; i++) {
Inside your loop, you'll probably want to get a reference to the individual person:
ABRecordRef person = CFArrayGetValueAtIndex(allPeople, i);
Then you want to compare the number you have (lets call that inNumber) to every phone number associated with that particular person. To do that, you first need a list of all the person's phone numbers:
ABMutableMultiValueRef phonelist = ABRecordCopyValue(person, kABPersonPhoneProperty);
Then, of course, you'll need to have an inner loop that loops over each of the individual person's phone numbers:
CFIndex numPhones = ABMultiValueGetCount(phones);
for (int j=0; j < numPhones; j++) {
Since the phone numbers have both numbers and labels associated with them, you'll need to extract the actual phone number string as an NSString:
CFTypeRef ABphone = ABMultiValueCopyValueAtIndex(phoneList, j);
NSString *personPhone = (NSString *)ABphone;
CFRelease(ABphone);
Now you can finally compare numbers! Do so with the standard NSString comparison methods, but remember that you need to worry about formatting, etc.
Once you find the person who has a phone number matching inNumber, you'll want the extract that person's image into a UIImage:
CFDataRef imageData = ABPersonCopyImageData(person);
UIImage *image = [UIImage imageWithData:(NSData *)imageData];
CFRelease(imageData);
When it comes time to exit, you'll need to clean up memory. A general rule of thumb for the AB framework is that anything with Get in the function name you don't need to release, and anything with Copy or Create, you do need to release. So, in this case you'll need to CFRelease() phonelist, allPeople, and addressbook, but not numPeople, person, or numPhones.
-(void)fetchAddressBook:(NSString *)searchnumber
{
ABAddressBookRef UsersAddressBook = ABAddressBookCreateWithOptions(NULL, NULL);
//contains details for all the contacts
CFArrayRef ContactInfoArray = ABAddressBookCopyArrayOfAllPeople(UsersAddressBook);
//get the total number of count of the users contact
CFIndex numberofPeople = CFArrayGetCount(ContactInfoArray);
//iterate through each record and add the value in the array
for (int i =0; i<numberofPeople; i++) {
ABRecordRef ref = CFArrayGetValueAtIndex(ContactInfoArray, i);
NSString *firstName = (__bridge NSString *)ABRecordCopyValue(ref, kABPersonFirstNameProperty);
//Get phone no. from contacts
ABMultiValueRef multi = ABRecordCopyValue(ref, kABPersonPhoneProperty);
UIImage *iimage;
NSString* phone;
for (CFIndex j=0; j < ABMultiValueGetCount(multi); j++) {
iimage=nil;
phone=nil;
phone = (__bridge NSString*)ABMultiValueCopyValueAtIndex(multi, j);
//if number matches
if([phone isEqualToString:searchnumber])
{
NSLog(#"equlas%#",searchnumber);
//if person has image store it
if (ABPersonHasImageData(ref)) {
CFDataRef imageData=ABPersonCopyImageDataWithFormat(ref, kABPersonImageFormatThumbnail);
iimage = [UIImage imageWithData:(__bridge NSData *)imageData];
}else{
//default image
iimage=[UIImage imageNamed:#"icon"];
}
//set image and name
userimage.image=iimage;
lblname.text=firstName;
return;
}
}
}
}
What I am trying to do (under 10.6)....
I have an image (jpeg) that includes an icon in the image file (that is you see an icon based on the image in the file, as opposed to a generic jpeg icon in file open dialogs in a program). I wish to edit the exif metadata, save it back to the image in a new file. Ideally I would like to save this back to an exact copy of the file (i.e. preserving any custom embedded icons created etc.), however, in my hands the icon is lost.
My code (some bits removed for ease of reading):
// set up source ref I THINK THE PROBLEM IS HERE - NOT GRABBING THE INITIAL DATA
CGImageSourceRef source = CGImageSourceCreateWithURL( (CFURLRef) URL,NULL);
// snag metadata
NSDictionary *metadata = (NSDictionary *) CGImageSourceCopyPropertiesAtIndex(source,0,NULL);
// make metadata mutable
NSMutableDictionary *metadataAsMutable = [[metadata mutableCopy] autorelease];
// grab exif
NSMutableDictionary *EXIFDictionary = [[[metadata objectForKey:(NSString *)kCGImagePropertyExifDictionary] mutableCopy] autorelease];
<< edit exif >>
// add back edited exif
[metadataAsMutable setObject:EXIFDictionary forKey:(NSString *)kCGImagePropertyExifDictionary];
// get source type
CFStringRef UTI = CGImageSourceGetType(source);
// set up write data
NSMutableData *data = [NSMutableData data];
CGImageDestinationRef destination = CGImageDestinationCreateWithData((CFMutableDataRef)data,UTI,1,NULL);
//add the image plus modified metadata PROBLEM HERE? NOT ADDING THE ICON
CGImageDestinationAddImageFromSource(destination,source,0, (CFDictionaryRef) metadataAsMutable);
// write to data
BOOL success = NO;
success = CGImageDestinationFinalize(destination);
// save data to disk
[data writeToURL:saveURL atomically:YES];
//cleanup
CFRelease(destination);
CFRelease(source);
I don't know if this is really a question of image handling, file handing, post-save processing (I could use sip), or me just being think (I suspect the last).
Nick
Don't you just hate it when you post something and then find the answer....
The way to deal with this is to use:
// grab the original unique icon
NSImage *theicon = [[NSWorkspace sharedWorkspace] iconForFile:full_file_path_of_original]];
// add it to the file after you have saved
BOOL done = [[NSWorkspace sharedWorkspace] setIcon:theicon forFile:full_file_path_to_new_file options:NSExcludeQuickDrawElementsIconCreationOption];
Doh!