When I am fetching photos using the ALAssetLibrary, for some images, the AssetRepresentation.size comes zero, which does not make the image, on my ImageView.
Here is the code:
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
[library enumerateGroupsWithTypes:ALAssetsGroupAlbum usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
if ([[group valueForProperty:ALAssetsGroupPropertyName] isEqual:self.groupName]) {
[group enumerateAssetsUsingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop){
//Get the asset type
NSString *assetType = [result valueForProperty:ALAssetPropertyType];
if ([assetType isEqualToString:ALAssetTypePhoto]) {
NSLog(#"Photo Asset");
}
//Get URLs for the assets
NSDictionary *assetURLs = [result valueForProperty:ALAssetPropertyURLs];
NSUInteger assetCounter = 0;
for (NSString *assetURLKey in assetURLs) {
assetCounter++;
}
//Get the asset's representation object
ALAssetRepresentation *assetRepresentation = [result defaultRepresentation];
//From this asset representation, we take out data for image and show it using imageview.
dispatch_async(dispatch_get_main_queue(), ^(void){
CGImageRef imgRef = [assetRepresentation fullResolutionImage];
//Img Construction
UIImage *image = [[[UIImage alloc] initWithCGImage:imgRef] autorelease];
NSLog(#"before %#:::%lld", [image description], [assetRepresentation size]); //Prints '0' for size
if((image != nil)&& [assetRepresentation size] != 0){
//display in image view
}
else{
// NSLog(#"Failed to load the image.");
}
});
}];
}
}failureBlock:^(NSError *error){
NSLog(#"Error retrieving photos: %#", error);
}];
[library release];
Please Help. What am I doing wrong here? and how should I get the image?
Joe Smith is right! You release the library too soon. The moment the AssetLibrary is released, all the asset object will be gone with it. And Because these enumeration is block codes so the release of AssetLibrary will be executed somewhere during the reading process.
I suggest that you create your assetLibrary in the app delegate to keep it alive and only reset it when you receive change notification ALAssetsLibraryChangedNotification from the ALAssetLibrary
I think you released the assets library too soon.
Related
Please find the below code for fetching images from Photo library
- (void) initilizeAssetForPhotoLibrary {
if (!assets) {
assets = [[NSMutableArray alloc] init];
} else {
[assets removeAllObjects];
}
ALAssetsGroupEnumerationResultsBlock assetsEnumerationBlock = ^(ALAsset *result, NSUInteger index, BOOL *stop) {
if (result) {
[assets addObject:result];
}
};
ALAssetsFilter *onlyPhotosFilter = [ALAssetsFilter allPhotos];
[assetsGroup setAssetsFilter:onlyPhotosFilter];
[assetsGroup enumerateAssetsUsingBlock:assetsEnumerationBlock];
}
- (NSMutableArray *) getImagesFromPhotoLibrary {
for(int i=0; i<assets.count; i++) {
ALAsset *asset = [assets objectAtIndex:i];
ALAssetRepresentation *assetRepresentation = [asset defaultRepresentation];
UIImage *getImage = [UIImage imageWithCGImage:[assetRepresentation fullScreenImage] scale:[assetRepresentation scale] orientation:(UIImageOrientation)[assetRepresentation orientation]];
[arrImages addObject:getImage];
}
return arrImages;
}
Actually my requirement is that I need to load all image from specific album in application for creating the slideshow.
When I am loading less than 100 images then it works fine but above it gets memory warning and after that it crashed.
Please help me if anyone has different idea to load images and less memory consumption. Thanks in advanced.
Keep all the images in memory will not do, there is just not enough memory for this.
You will need to fill the array with the ALAssetRepresentation of the images and load the image only when you are ready to display it. This way you will only have the image in memory that you are really displaying.
then write down below code and let me know it is working or not!!!
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,
(unsigned long)NULL), ^(void) {
for(int i=0; i<assets.count; i++) {
ALAsset *asset = [assets objectAtIndex:i];
ALAssetRepresentation *assetRepresentation = [asset defaultRepresentation];
UIImage *getImage = [UIImage imageWithCGImage:[assetRepresentation fullScreenImage] scale:[assetRepresentation scale] orientation:(UIImageOrientation)[assetRepresentation orientation]];
[arrImages addObject:getImage];
}
return arrImages;
});
Happy Coding...!!!!
I am experimenting with the Social Framework.
I was wondering if there is any possible way to attach the last photo taken and currently saved in the camera roll using this implementation from my app:
- (IBAction)shareByActivity:(id)sender {
NSArray *activityItems;
if (self.sharingImage != nil) {
activityItems = #[self.sharingImage, self.sharingText, self.addURL];
} else {
activityItems = #[self.sharingText, self.addURL];
}
UIActivityViewController *activityController =
[[UIActivityViewController alloc] initWithActivityItems:activityItems
applicationActivities:nil];
[self presentViewController:activityController
animated:YES completion:nil];
}
If so how do I modify the shareImage name in this specific portion of my -(void)viewDidLoad ?
self.sharingImage = [UIImage imageNamed:#"notSureWhatToPutHere"];
Everything works well, the social panel opens and has all the needed service. My only request is to find out how to call the latest image from the camera roll.
I am not sure if I need the image real name or if there is any other way to achieve what i would like: a post with a picture attached (most recent picture in camera roll).
Any help is appreciated.
You can pretty painlessly get the last image in the camera roll using the asset library framework. Give this a try:
#import <AssetsLibrary/AssetsLibrary.h>
Then to get the image:
ALAssetsLibrary *cameraRoll = [[ALAssetsLibrary alloc] init];
[cameraRoll enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos usingBlock:^(ALAssetsGroup *images, BOOL *stop) {
[images setAssetsFilter:[ALAssetsFilter allPhotos]];
[images enumerateAssetsAtIndexes:[NSIndexSet indexSetWithIndex:[images numberOfAssets] - 1] options:0 usingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop){
if (result) {
ALAssetRepresentation *rep = [result defaultRepresentation];
self.sharingImage = [UIImage imageWithCGImage:[rep fullScreenImage]];
}
}];
}
failureBlock: ^(NSError *error) {
NSLog(#"An error occured: %#",error);
}];
Thanks for the great help NSPostWhenIdle!
I was able to resolve the issue of getting "newest photos" from camera roll by moving my ALAssettsLibrary chuck of code away from viewDidLoad and created a refreshAlbum
- (void) refreshAlbum
{
ALAssetsLibrary *cameraRoll = [[ALAssetsLibrary alloc] init];
[cameraRoll enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos usingBlock:^(ALAssetsGroup *images, BOOL *stop) {
[images setAssetsFilter:[ALAssetsFilter allPhotos]];
[images enumerateAssetsAtIndexes:[NSIndexSet indexSetWithIndex:[images numberOfAssets] - 1] options:0 usingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop)
{
if (result) {
ALAssetRepresentation *rep = [result defaultRepresentation];
self.sharingImage = [UIImage imageWithCGImage:[rep fullScreenImage]];
}
}];
}
failureBlock: ^(NSError *error) {
NSLog(#"An error occured: %#",error);
}];
}
Then I am calling the newly created refreshAlbum from the same button that enable the shareByActivity
- (IBAction)refreshButton:(id)sender {
[self refreshAlbum];
}
This work particularly well as my app does not have any picture to share as it starts up.
The first time that imageShare become available is after activating the shareByActivity button that now carries the refreshButton function as well!
Thanks again, this really work.
This question already has answers here:
UIImagePickerController and extracting EXIF data from existing photos
(18 answers)
Closed 7 years ago.
How can we get Exif information from UIImage selected from UIImagePickerController?
I had done much R&D for this and got many replies but still failed to implement this.
I had gone through this this and this link
Please help me to solve this problem.
Thanks in advance..
Interesting question! I came up with the following solution working for images picked from your photo library (note my code is using ARC):
Import AssetsLibrary.framework and ImageIO.framework.
Then include the needed classes inside your .h-file:
#import <AssetsLibrary/ALAsset.h>
#import <AssetsLibrary/ALAssetRepresentation.h>
#import <ImageIO/CGImageSource.h>
#import <ImageIO/CGImageProperties.h>
And put this inside your imagePickerController:didFinishPickingMediaWithInfo: delegate method:
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
[library assetForURL:[info objectForKey:UIImagePickerControllerReferenceURL]
resultBlock:^(ALAsset *asset) {
ALAssetRepresentation *image_representation = [asset defaultRepresentation];
// create a buffer to hold image data
uint8_t *buffer = (Byte*)malloc(image_representation.size);
NSUInteger length = [image_representation getBytes:buffer fromOffset: 0.0 length:image_representation.size error:nil];
if (length != 0) {
// buffer -> NSData object; free buffer afterwards
NSData *adata = [[NSData alloc] initWithBytesNoCopy:buffer length:image_representation.size freeWhenDone:YES];
// identify image type (jpeg, png, RAW file, ...) using UTI hint
NSDictionary* sourceOptionsDict = [NSDictionary dictionaryWithObjectsAndKeys:(id)[image_representation UTI] ,kCGImageSourceTypeIdentifierHint,nil];
// create CGImageSource with NSData
CGImageSourceRef sourceRef = CGImageSourceCreateWithData((__bridge CFDataRef) adata, (__bridge CFDictionaryRef) sourceOptionsDict);
// get imagePropertiesDictionary
CFDictionaryRef imagePropertiesDictionary;
imagePropertiesDictionary = CGImageSourceCopyPropertiesAtIndex(sourceRef,0, NULL);
// get exif data
CFDictionaryRef exif = (CFDictionaryRef)CFDictionaryGetValue(imagePropertiesDictionary, kCGImagePropertyExifDictionary);
NSDictionary *exif_dict = (__bridge NSDictionary*)exif;
NSLog(#"exif_dict: %#",exif_dict);
// save image WITH meta data
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSURL *fileURL = nil;
CGImageRef imageRef = CGImageSourceCreateImageAtIndex(sourceRef, 0, imagePropertiesDictionary);
if (![[sourceOptionsDict objectForKey:#"kCGImageSourceTypeIdentifierHint"] isEqualToString:#"public.tiff"])
{
fileURL = [NSURL fileURLWithPath:[NSString stringWithFormat:#"%#/%#.%#",
documentsDirectory,
#"myimage",
[[[sourceOptionsDict objectForKey:#"kCGImageSourceTypeIdentifierHint"] componentsSeparatedByString:#"."] objectAtIndex:1]
]];
CGImageDestinationRef dr = CGImageDestinationCreateWithURL ((__bridge CFURLRef)fileURL,
(__bridge CFStringRef)[sourceOptionsDict objectForKey:#"kCGImageSourceTypeIdentifierHint"],
1,
NULL
);
CGImageDestinationAddImage(dr, imageRef, imagePropertiesDictionary);
CGImageDestinationFinalize(dr);
CFRelease(dr);
}
else
{
NSLog(#"no valid kCGImageSourceTypeIdentifierHint found …");
}
// clean up
CFRelease(imageRef);
CFRelease(imagePropertiesDictionary);
CFRelease(sourceRef);
}
else {
NSLog(#"image_representation buffer length == 0");
}
}
failureBlock:^(NSError *error) {
NSLog(#"couldn't get asset: %#", error);
}
];
One thing I noticed is, that iOS will ask the user to allow location services – if he denies, you won't be abled to get the image data …
EDIT
Added code to save the image including its meta data. It's a quick approach, so maybe there is a better way, but it works!
These answers all seem extremely complex. If the image has been saved to the Camera Roll, and you have the ALAsset (either from UIImagePicker or ALAssetLibrary) you can get the metadata like so:
asset.defaultRepresentation.metadata;
If you want to save that image from camera roll to another location (say in Sandbox/Documents) simply do:
CGImageDestinationRef imageDestinationRef = CGImageDestinationCreateWithURL((__bridge CFURLRef)urlToSaveTo, kUTTypeJPEG, 1, NULL);
CFDictionaryRef imagePropertiesRef = (__bridge CFDictionaryRef)asset.defaultRepresentation.metadata;
CGImageDestinationAddImage(imageDestinationRef, asset.defaultRepresentation.fullResolutionImage, imagePropertiesRef);
if (!CGImageDestinationFinalize(imageDestinationRef)) NSLog(#"Failed to copy photo on save to %#", urlToSaveTo);
CFRelease(imageDestinationRef);
I had found solution and got answer from here
From here We can get GPS info as well..
Amazing and thanks all for helping me to solve this problem.
UPDATE
This is another function that I had created myself, also return Exif data as well as GPS data and in this function we doesn't need any third party library.. but you have to turn on location services for this. and use current latitude and longitude for that. so have to use CoreLocation.framework
//FOR CAMERA IMAGE
-(NSMutableData *)getImageWithMetaData:(UIImage *)pImage
{
NSData* pngData = UIImagePNGRepresentation(pImage);
CGImageSourceRef source = CGImageSourceCreateWithData((CFDataRef)pngData, NULL);
NSDictionary *metadata = (NSDictionary *) CGImageSourceCopyPropertiesAtIndex(source, 0, NULL);
NSMutableDictionary *metadataAsMutable = [[metadata mutableCopy]autorelease];
[metadata release];
//For GPS Dictionary
NSMutableDictionary *GPSDictionary = [[[metadataAsMutable objectForKey:(NSString *)kCGImagePropertyGPSDictionary]mutableCopy]autorelease];
if(!GPSDictionary)
GPSDictionary = [NSMutableDictionary dictionary];
[GPSDictionary setValue:[NSNumber numberWithDouble:currentLatitude] forKey:(NSString*)kCGImagePropertyGPSLatitude];
[GPSDictionary setValue:[NSNumber numberWithDouble:currentLongitude] forKey:(NSString*)kCGImagePropertyGPSLongitude];
NSString* ref;
if (currentLatitude <0.0)
ref = #"S";
else
ref =#"N";
[GPSDictionary setValue:ref forKey:(NSString*)kCGImagePropertyGPSLatitudeRef];
if (currentLongitude <0.0)
ref = #"W";
else
ref =#"E";
[GPSDictionary setValue:ref forKey:(NSString*)kCGImagePropertyGPSLongitudeRef];
[GPSDictionary setValue:[NSNumber numberWithFloat:location.altitude] forKey:(NSString*)kCGImagePropertyGPSAltitude];
//For EXIF Dictionary
NSMutableDictionary *EXIFDictionary = [[[metadataAsMutable objectForKey:(NSString *)kCGImagePropertyExifDictionary]mutableCopy]autorelease];
if(!EXIFDictionary)
EXIFDictionary = [NSMutableDictionary dictionary];
[EXIFDictionary setObject:[NSDate date] forKey:(NSString*)kCGImagePropertyExifDateTimeOriginal];
[EXIFDictionary setObject:[NSDate date] forKey:(NSString*)kCGImagePropertyExifDateTimeDigitized];
//add our modified EXIF data back into the image’s metadata
[metadataAsMutable setObject:EXIFDictionary forKey:(NSString *)kCGImagePropertyExifDictionary];
[metadataAsMutable setObject:GPSDictionary forKey:(NSString *)kCGImagePropertyGPSDictionary];
CFStringRef UTI = CGImageSourceGetType(source);
NSMutableData *dest_data = [NSMutableData data];
CGImageDestinationRef destination = CGImageDestinationCreateWithData((CFMutableDataRef)dest_data, UTI, 1, NULL);
if(!destination)
dest_data = [[pngData mutableCopy] autorelease];
else
{
CGImageDestinationAddImageFromSource(destination, source, 0, (CFDictionaryRef) metadataAsMutable);
BOOL success = CGImageDestinationFinalize(destination);
if(!success)
dest_data = [[pngData mutableCopy] autorelease];
}
if(destination)
CFRelease(destination);
CFRelease(source);
return dest_data;
}
//FOR PHOTO LIBRARY IMAGE
-(NSMutableData *)getImagedataPhotoLibrary:(NSDictionary *)pImgDictionary andImage:(UIImage *)pImage
{
NSData* data = UIImagePNGRepresentation(pImage);
CGImageSourceRef source = CGImageSourceCreateWithData((CFDataRef)data, NULL);
NSMutableDictionary *metadataAsMutable = [[pImgDictionary mutableCopy]autorelease];
CFStringRef UTI = CGImageSourceGetType(source);
NSMutableData *dest_data = [NSMutableData data];
//For Mutabledata
CGImageDestinationRef destination = CGImageDestinationCreateWithData((CFMutableDataRef)dest_data, UTI, 1, NULL);
if(!destination)
dest_data = [[data mutableCopy] autorelease];
else
{
CGImageDestinationAddImageFromSource(destination, source, 0, (CFDictionaryRef) metadataAsMutable);
BOOL success = CGImageDestinationFinalize(destination);
if(!success)
dest_data = [[data mutableCopy] autorelease];
}
if(destination)
CFRelease(destination);
CFRelease(source);
return dest_data;
}
and We will retrieve that data like this
//FOR CAMERA IMAGE
NSData *originalImgData = [self getImageWithMetaData:imgOriginal];
//FOR PHOTO LIBRARY IMAGE
[self getImagedataPhotoLibrary:[[myasset defaultRepresentation] metadata] andImage:imgOriginal];
For all of this you should have to Import AssetsLibrary.framework and ImageIO.framework.
I have used this method for getting the exifdata dictionary from image , I hope this will also work for you
-(void)getExifDataFromImage:(UIImage *)currentImage
{
NSData* pngData = UIImageJPEGRepresentation(currentImage, 1.0);
CGImageSourceRef mySourceRef = CGImageSourceCreateWithData((CFDataRef)pngData, NULL);
//CGImageSourceRef mySourceRef = CGImageSourceCreateWithURL((__bridge CFURLRef)myURL, NULL);
if (mySourceRef != NULL)
{
NSDictionary *myMetadata = (__bridge NSDictionary *)CGImageSourceCopyPropertiesAtIndex(mySourceRef,0,NULL);
NSDictionary *exifDic = [myMetadata objectForKey:(NSString *)kCGImagePropertyExifDictionary];
NSDictionary *tiffDic = [myMetadata objectForKey:(NSString *)kCGImagePropertyTIFFDictionary];
NSLog(#"exifDic properties: %#", myMetadata); //all data
float rawShutterSpeed = [[exifDic objectForKey:(NSString *)kCGImagePropertyExifExposureTime] floatValue];
int decShutterSpeed = (1 / rawShutterSpeed);
NSLog(#"Camera %#",[tiffDic objectForKey:(NSString *)kCGImagePropertyTIFFModel]);
NSLog(#"Focal Length %#mm",[exifDic objectForKey:(NSString *)kCGImagePropertyExifFocalLength]);
NSLog(#"Shutter Speed %#", [NSString stringWithFormat:#"1/%d", decShutterSpeed]);
NSLog(#"Aperture f/%#",[exifDic objectForKey:(NSString *)kCGImagePropertyExifFNumber]);
NSNumber *ExifISOSpeed = [[exifDic objectForKey:(NSString*)kCGImagePropertyExifISOSpeedRatings] objectAtIndex:0];
NSLog(#"ISO %ld",[ExifISOSpeed integerValue]);
NSLog(#"Taken %#",[exifDic objectForKey:(NSString*)kCGImagePropertyExifDateTimeDigitized]);
}
}
You need ALAssetsLibrary to actually retrieve the EXIF info from an image. The EXIF is added to an image only when it is saved to the Photo Library. Even if you use ALAssetLibrary to get an image asset from the library, it will lose all EXIF info if you set it to a UIImage.
I have tried to insert GPS coordinates into image metadata picked by iPad Camera as it was suggested by Mehul.
It Works, Thank you for your post.
P.S.
Who intends to use that code, just substitude the two geolocations at the top of the function -(NSMutableData *)getImageWithMetaData:(UIImage *)pImage {
double currentLatitude = [locationManager location].coordinate.latitude;
double currentLongitude = [locationManager location].coordinate.longitude;
...
By supposing that you have already initializied somewhere locationManager in your code, like this:
locationManager = [[CLLocationManager alloc] init];
[locationManager setDesiredAccuracy:kCLLocationAccuracyBest];
[locationManager setDelegate:self]; // Not necessary in this case
[locationManager startUpdatingLocation]; // Not neccessary in this case
and by importing CoreLocation/CoreLocation.h and ImageIO/ImageIO.h headers with associated frameworks.
I know how to let user select an image from UIImagePickerController, but I don't want that.
I just want to have NSArray of images stored in the phone, but I don't want to involve user (to select a one and then have that image...),rather, I have created my own custom Image selector controller and want to have source as the gallary.
You can easily do that using the AVFoundation and AssetsLibrary framework. Here is the code to access all the photos:
-(void)addPhoto:(ALAssetRepresentation *)asset
{
//NSLog(#"Adding photo!");
[photos addObject:asset];
}
-(void)loadPhotos
{
photos = [[NSMutableArray alloc] init];
library = [[ALAssetsLibrary alloc] init];
// Enumerate just the photos and videos group by using ALAssetsGroupSavedPhotos.
if([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone)
{
[library enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos usingBlock:^(ALAssetsGroup *group, BOOL *stop)
{
// Within the group enumeration block, filter if necessary
[group setAssetsFilter:[ALAssetsFilter allPhotos]];
[group enumerateAssetsUsingBlock:^(ALAsset *alAsset, NSUInteger index, BOOL *innerStop)
{
// The end of the enumeration is signaled by asset == nil.
if (alAsset)
{
ALAssetRepresentation *representation = [alAsset defaultRepresentation];
[self addPhoto:representation];
}
else
{
NSLog(#"Done! Count = %d", photos.count);
//Do something awesome
}
}];
}
failureBlock: ^(NSError *error) {
// Typically you should handle an error more gracefully than this.
NSLog(#"No groups");
}];
}
}
I am aware of how to save metadata using ALAssets. But, I want to save an image, or upload it somewhere, with exif intact. I have exif data as an NSDictionary. But how can I inject it properly into a UIImage (or probably an NSData JPEG representation)?
I am using UIImagePickerController to get the image from the camera and my flow is a bit different than the one described by Chiquis. Here it is:
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
UIImage *image = info[#"UIImagePickerControllerOriginalImage"];
NSString *fullPhotoFilename = ...; // generate the photo name and path here
NSData *photoData = [UIImage taggedImageData:image.jpegData metadata:info[#"UIImagePickerControllerMediaMetadata"] orientation:image.imageOrientation];
[photoData writeToFile:fullPhotoFilename atomically:YES];
}
And using a UIImage category to put combine the image data with its metadata:
#import <ImageIO/ImageIO.h>
#import "UIImage+Tagging.h"
#import "LocationHelper.h"
#implementation UIImage (Tagging)
+ (NSData *)writeMetadataIntoImageData:(NSData *)imageData metadata:(NSMutableDictionary *)metadata {
// create an imagesourceref
CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef) imageData, NULL);
// this is the type of image (e.g., public.jpeg)
CFStringRef UTI = CGImageSourceGetType(source);
// create a new data object and write the new image into it
NSMutableData *dest_data = [NSMutableData data];
CGImageDestinationRef destination = CGImageDestinationCreateWithData((__bridge CFMutableDataRef)dest_data, UTI, 1, NULL);
if (!destination) {
NSLog(#"Error: Could not create image destination");
}
// add the image contained in the image source to the destination, overidding the old metadata with our modified metadata
CGImageDestinationAddImageFromSource(destination, source, 0, (__bridge CFDictionaryRef) metadata);
BOOL success = NO;
success = CGImageDestinationFinalize(destination);
if (!success) {
NSLog(#"Error: Could not create data from image destination");
}
CFRelease(destination);
CFRelease(source);
return dest_data;
}
+ (NSData *)taggedImageData:(NSData *)imageData metadata:(NSDictionary *)metadata orientation:(UIImageOrientation)orientation {
CLLocationManager *locationManager = [CLLocationManager new];
CLLocation *location = [locationManager location];
NSMutableDictionary *newMetadata = [NSMutableDictionary dictionaryWithDictionary:metadata];
if (!newMetadata[(NSString *)kCGImagePropertyGPSDictionary] && location) {
newMetadata[(NSString *)kCGImagePropertyGPSDictionary] = [LocationHelper gpsDictionaryForLocation:location];
}
// Reference: http://sylvana.net/jpegcrop/exif_orientation.html
int newOrientation;
switch (orientation) {
case UIImageOrientationUp:
newOrientation = 1;
break;
case UIImageOrientationDown:
newOrientation = 3;
break;
case UIImageOrientationLeft:
newOrientation = 8;
break;
case UIImageOrientationRight:
newOrientation = 6;
break;
case UIImageOrientationUpMirrored:
newOrientation = 2;
break;
case UIImageOrientationDownMirrored:
newOrientation = 4;
break;
case UIImageOrientationLeftMirrored:
newOrientation = 5;
break;
case UIImageOrientationRightMirrored:
newOrientation = 7;
break;
default:
newOrientation = -1;
}
if (newOrientation != -1) {
newMetadata[(NSString *)kCGImagePropertyOrientation] = #(newOrientation);
}
NSData *newImageData = [self writeMetadataIntoImageData:imageData metadata:newMetadata];
return newImageData;
}
And finally, here is the method I am using to generate the needed GPS dictionary:
+ (NSDictionary *)gpsDictionaryForLocation:(CLLocation *)location {
NSTimeZone *timeZone = [NSTimeZone timeZoneWithName:#"UTC"];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setTimeZone:timeZone];
[formatter setDateFormat:#"HH:mm:ss.SS"];
NSDictionary *gpsDict = #{(NSString *)kCGImagePropertyGPSLatitude: #(fabs(location.coordinate.latitude)),
(NSString *)kCGImagePropertyGPSLatitudeRef: ((location.coordinate.latitude >= 0) ? #"N" : #"S"),
(NSString *)kCGImagePropertyGPSLongitude: #(fabs(location.coordinate.longitude)),
(NSString *)kCGImagePropertyGPSLongitudeRef: ((location.coordinate.longitude >= 0) ? #"E" : #"W"),
(NSString *)kCGImagePropertyGPSTimeStamp: [formatter stringFromDate:[location timestamp]],
(NSString *)kCGImagePropertyGPSAltitude: #(fabs(location.altitude)),
};
return gpsDict;
}
Hope it helps someone. Thanks to Gustavo Ambrozio, Chiquis and several others SO members I was able to piece it together and use it in my project.
UIImage does not contain metadata information (it is stripped). So if you want to save it without using the imagepicker method (not in camera roll):
Follow the answer here to write to a file with the metadata intact:
Problem setting exif data for an image
no idea why would this be downvoted but here is the method:
In this case im getting the image through AVFoundation and this is what goes in the
[[self stillImageOutput] captureStillImageAsynchronouslyFromConnection:videoConnection
completionHandler:^(CMSampleBufferRef imageSampleBuffer, NSError *error)
{
// code here
}
block code:
CFDictionaryRef metaDict = CMCopyDictionaryOfAttachments(NULL, imageSampleBuffer, kCMAttachmentMode_ShouldPropagate);
CFMutableDictionaryRef mutable = CFDictionaryCreateMutableCopy(NULL, 0, metaDict);
// Create formatted date
NSTimeZone *timeZone = [NSTimeZone timeZoneWithName:#"UTC"];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setTimeZone:timeZone];
[formatter setDateFormat:#"HH:mm:ss.SS"];
// Create GPS Dictionary
NSDictionary *gpsDict = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithFloat:fabs(loc.coordinate.latitude)], kCGImagePropertyGPSLatitude
, ((loc.coordinate.latitude >= 0) ? #"N" : #"S"), kCGImagePropertyGPSLatitudeRef
, [NSNumber numberWithFloat:fabs(loc.coordinate.longitude)], kCGImagePropertyGPSLongitude
, ((loc.coordinate.longitude >= 0) ? #"E" : #"W"), kCGImagePropertyGPSLongitudeRef
, [formatter stringFromDate:[loc timestamp]], kCGImagePropertyGPSTimeStamp
, [NSNumber numberWithFloat:fabs(loc.altitude)], kCGImagePropertyGPSAltitude
, nil];
// The gps info goes into the gps metadata part
CFDictionarySetValue(mutable, kCGImagePropertyGPSDictionary, (__bridge void *)gpsDict);
// Here just as an example im adding the attitude matrix in the exif comment metadata
CMRotationMatrix m = att.rotationMatrix;
GLKMatrix4 attMat = GLKMatrix4Make(m.m11, m.m12, m.m13, 0, m.m21, m.m22, m.m23, 0, m.m31, m.m32, m.m33, 0, 0, 0, 0, 1);
NSMutableDictionary *EXIFDictionary = (__bridge NSMutableDictionary*)CFDictionaryGetValue(mutable, kCGImagePropertyExifDictionary);
[EXIFDictionary setValue:NSStringFromGLKMatrix4(attMat) forKey:(NSString *)kCGImagePropertyExifUserComment];
CFDictionarySetValue(mutable, kCGImagePropertyExifDictionary, (__bridge void *)EXIFDictionary);
NSData *jpeg = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer] ;
After this code you will have your image in the jpeg nsdata and the correspoding dictionary for that image in the mutable cfdictionary.
All you have to do now is:
CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)jpeg, NULL);
CFStringRef UTI = CGImageSourceGetType(source); //this is the type of image (e.g., public.jpeg)
NSMutableData *dest_data = [NSMutableData data];
CGImageDestinationRef destination = CGImageDestinationCreateWithData((__bridge CFMutableDataRef)dest_data,UTI,1,NULL);
if(!destination) {
NSLog(#"***Could not create image destination ***");
}
//add the image contained in the image source to the destination, overidding the old metadata with our modified metadata
CGImageDestinationAddImageFromSource(destination,source,0, (CFDictionaryRef) mutable);
//tell the destination to write the image data and metadata into our data object.
//It will return false if something goes wrong
BOOL success = CGImageDestinationFinalize(destination);
if(!success) {
NSLog(#"***Could not create data from image destination ***");
}
//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
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0]; // Get documents folder
NSString *dataPath = [documentsDirectory stringByAppendingPathComponent:#"ImagesFolder"];
NSError *error;
if (![[NSFileManager defaultManager] fileExistsAtPath:dataPath])
[[NSFileManager defaultManager] createDirectoryAtPath:dataPath withIntermediateDirectories:NO attributes:nil error:&error]; //Create folder
// NSString *imageName = #"ImageName";
NSString *fullPath = [dataPath stringByAppendingPathComponent:[NSString stringWithFormat:#"%#.jpg", name]]; //add our image to the path
[dest_data writeToFile:fullPath atomically:YES];
//cleanup
CFRelease(destination);
CFRelease(source);
Note how I'm not saving using the ALAssets but directly into a folder of my choice.
Btw most of this code can be found in the link I posted at first.
There is easier way. If you need to save some exif, you can use SimpleExif pod
First create a ExifContainer:
ExifContainer *container = [[ExifContainer alloc] init];
and populate it with all requred data:
[container addUserComment:#"A long time ago, in a galaxy far, far away"];
[container addCreationDate:[NSDate dateWithTimeIntervalSinceNow:-10000000]];
[container addLocation:locations[0]];
Then you can add this data to image:
NSData *imageData = [[UIImage imageNamed:#"DemoImage"] addExif:container];
Then you just save this data as a JPEG
I faced the same problem, now I can upload files with EXIF data, also you can compress photo if need it, this solved the issue for me:
// Get your image.
UIImage *loImgPhoto = [self getImageFromAsset:loPHAsset];
// Get your metadata (includes the EXIF data).
CGImageSourceRef loImageOriginalSource = CGImageSourceCreateWithData(( CFDataRef) loDataFotoOriginal, NULL);
NSDictionary *loDicMetadata = (__bridge NSDictionary *) CGImageSourceCopyPropertiesAtIndex(loImageOriginalSource, 0, NULL);
// Set your compression quality (0.0 to 1.0).
NSMutableDictionary *loDicMutableMetadata = [loDicMetadata mutableCopy];
[loDicMutableMetadata setObject:#(lfCompressionQualityValue) forKey:(__bridge NSString *)kCGImageDestinationLossyCompressionQuality];
// Create an image destination.
NSMutableData *loNewImageDataWithExif = [NSMutableData data];
CGImageDestinationRef loImgDestination = CGImageDestinationCreateWithData((__bridge CFMutableDataRef)loNewImageDataWithExif, CGImageSourceGetType(loImageOriginalSource), 1, NULL);
// Add your image to the destination.
CGImageDestinationAddImage(loImgDestination, loImgPhoto.CGImage, (__bridge CFDictionaryRef) loDicMutableMetadata);
// Finalize the destination.
if (CGImageDestinationFinalize(loImgDestination))
{
NSLog(#"Successful image creation.");
// process the image rendering, adjustment data creation and finalize the asset edit.
//Upload photo with EXIF metadata
[self myUploadMethod:loNewImageDataWithExif];
}
else
{
NSLog(#"Error -> failed to finalize the image.");
}
CFRelease(loImageOriginalSource);
CFRelease(loImgDestination);
getImageFromAsset method:
-(UIImage *)getImageFromAsset:(PHAsset *)aPHAsset
{
__block UIImage *limgImageResult;
PHImageRequestOptions *lPHImageRequestOptions = [PHImageRequestOptions new];
lPHImageRequestOptions.synchronous = YES;
[self.imageManager requestImageForAsset:aPHAsset
targetSize:PHImageManagerMaximumSize
contentMode:PHImageContentModeDefault//PHImageContentModeAspectFit
options:lPHImageRequestOptions
resultHandler:^(UIImage *limgImage, NSDictionary *info) {
limgImageResult = limgImage;
}];
return limgImageResult;
}
Here's the basics of setting Make and Model metadata on a .jpg file in Swift 3 https://gist.github.com/lacyrhoades/09d8a367125b6225df5038aec68ed9e7 The higher level versions, like using ExifContainer pod, did not work for me.