获取图片的metaData

获取图片的metaData

 

 

获取简易的metaData较为容易,以下是测试图:

以下是本人提供的源码:

UIImage+MetaData.h

//

// UIImage+MetaData.h

// PictureInfo

// Created by YouXianMing on 14-8-27.

// Copyright (c) 2014年 YouXianMing. All rights reserved.

#import UIKit/UIKit.h 

@interface UIImage (MetaData)

- (NSDictionary *)JPEGmetaData;

- (NSDictionary *)PNGmetaData;

@end

UIImage+MetaData.h

//

// UIImage+MetaData.m

// PictureInfo

// Created by YouXianMing on 14-8-27.

// Copyright (c) 2014年 YouXianMing. All rights reserved.

#import "UIImage+MetaData.h"

#import AssetsLibrary/AssetsLibrary.h 

#import ImageIO/ImageIO.h 

@implementation UIImage (MetaData)

- (NSDictionary *)JPEGmetaData

 if (self == nil)

 return nil;

 // 转换成jpegData,信息要多一些

 NSData *jpegData = UIImageJPEGRepresentation(self, 1.0);

 CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)jpegData, NULL);

 CFDictionaryRef imageMetaData = CGImageSourceCopyPropertiesAtIndex(source, 0, NULL);

 CFRelease(source);

 NSDictionary *metaDataInfo = CFBridgingRelease(imageMetaData);

 return metaDataInfo;

- (NSDictionary *)PNGmetaData

 if (self == nil)

 return nil;

 NSData *pngData = UIImagePNGRepresentation(self);

 CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)pngData , NULL);

 CFDictionaryRef imageMetaData = CGImageSourceCopyPropertiesAtIndex(source, 0, NULL);

 CFRelease(source);

 NSDictionary *metaDataInfo = CFBridgingRelease(imageMetaData);

 return metaDataInfo;

@end

使用情况:

//

// AppDelegate.m

// GetPictureInfo

// Copyright (c) 2014年 Y.X. All rights reserved.

#import "AppDelegate.h"

#import "UIImage+MetaData.h"

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

 self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

 // Override point for customization after application launch.

 NSLog(@"%@", [[UIImage imageNamed:@"IMG_0151.JPG"] JPEGmetaData]);

 self.window.backgroundColor = [UIColor whiteColor];

 [self.window makeKeyAndVisible];

 return YES;

@end

以下是打印信息:

{
    ColorModel = RGB;
    Depth = 8;
    Orientation = 1;
    PixelHeight = 1936;
    PixelWidth = 2592;
    "{Exif}" =     {
        ColorSpace = 1;
        PixelXDimension = 2592;
        PixelYDimension = 1936;
    };
    "{JFIF}" =     {
        DensityUnit = 0;
        JFIFVersion =         (
            1,
            1
        );
        XDensity = 1;
        YDensity = 1;
    };
    "{TIFF}" =     {
        Orientation = 1;
    };
}
几个需要注意的地方:

1. 需要引入两个库

2. 一些需要注意的细节

你以为结束了么?没有呢,你还没取到图片的经纬度信息,对吧,一下给你提供资料自己去尝试:)

http://stackoverflow.com/questions/9766394/get-exif-data-from-uiimage-uiimagepickercontroller

 

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"],

 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(@"couldnt get asset: %@", error);

];

One thing I noticed is, that iOS will ask the user to allow location services – if he denies, you wont be abled to get the image data …

EDIT

Added code to save the image including its meta data. Its a quick approach, so maybe there is a better way, but it works!

@Marvin Im using ARC. __bridge is one of a hand full of keywords, which tell ARC about the objects ownership so it can properly clean them up. The simplest case is a __bridge cast, for which ARC will not do any extra work (it assumes you handle the objects memory yourself). –  dom Mar 21 12 at 6:45

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 doesnt 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 useCoreLocation.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.

where is currentLatitude coming from? Are you setting this from the standard CoreLocation calls before you invoke the UIImagePicker or are you reading it directly from the image that was returned? –  Paul Cezanne Apr 24 12 at 14:55
ahhh, it can be inaccurate then. You call CoreLocation, invoke UIImagePicker and then physically move the device a distance before taking the image. You will now have inaccurate latitude and longitude. Drat... –  Paul Cezanne Apr 25 12 at 8:48
but youll never know the location when the shutter button is pressed, just the current location. (You can keep on moving after the shutter button is pressed.) –  Paul Cezanne Apr 25 12 at 9:54

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);

It also return much more info than the other ways: They wont return infos Stored in {TIFF} like Model, Make, Copyright, Artist and so on. This should be marked as answer! –  Benedikt Mokroß Dec 7 13 at 17:02

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.

积分图像（Integral image） 积分图算法由Crow在1984年首次提出，是为了在多尺度透视投影中提高渲染速度。积分图算法是一种快速计算图像区域和以及图像区域平方和的算法。它的核心思想就是对每一个图像建立起自己的积分图查找表，在图像处理的阶段就可以根据预先建立积分图查找表直接查找从而实现对均值卷积的线性时间计算。做到了卷积执行的时间与窗口大小无关。之前介绍的NL-means算法就可以采用积分图算法进行优化加速。
Image图片查找不存在时(九) 在实际的开发中，常常会遇到关于图片的问题。 如图片显示的问题，然而在显示图片的过程中，常常也会遇到一些问题，如图片不存在，图片引用的路径不匹配等。