Iphone 从UIImage-UIImagePickerController获取Exif数据

如何从UIImagePickerController中选择的UIImage获取Exif信息

我为此做了很多研发工作，得到了很多回复，但仍然没有实现

我已经通过了这个链接

请帮我解决这个问题

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提前感谢..

有趣的问题！我为从您的照片库中拾取的图像提出了以下解决方案（请注意，我的代码使用的是ARC）：

导入

AssetLibrary.framework

和

ImageIO.framework

然后在.h文件中包含所需的类：

#import <AssetsLibrary/ALAsset.h>
#import <AssetsLibrary/ALAssetRepresentation.h>
#import <ImageIO/CGImageSource.h>
#import <ImageIO/CGImageProperties.h>

我注意到的一件事是，iOS会要求用户允许定位服务–如果他拒绝，你将无法获取图像数据

编辑

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添加了用于保存图像（包括其元数据）的代码。这是一个快速的方法，所以也许有更好的方法，但它是有效的

我找到了解决办法，并从

从这里我们还可以获得GPS信息

太棒了，谢谢大家帮我解决这个问题

更新

这是我自己创建的另一个函数，也返回Exif数据以及GPS数据，在这个函数中，我们不需要任何第三方库。。但你必须为此打开定位服务。并使用当前的纬度和经度。因此必须使用

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;
}

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对于所有这些，您必须导入

assetsbrary.framework

和

ImageIO.framework

您需要从图像中实际检索EXIF信息。只有在将EXIF保存到照片库时，才会将其添加到图像中。即使您使用ALAssetLibrary从库中获取图像资源，如果您将其设置为UIImage，它也会丢失所有EXIF信息。

我尝试将GPS坐标插入到iPad摄像头拾取的图像元数据中，正如Mehul建议的那样。 这很有效，谢谢你的帖子

附言。 谁打算使用该代码，只需将函数顶部的两个地理位置-（NSMutableData*）getImageWithMetaData:（UIImage*）pImage替换即可{

假设您已经在代码中初始化了locationManager，如下所示：

    locationManager = [[CLLocationManager alloc] init];
    [locationManager setDesiredAccuracy:kCLLocationAccuracyBest];
    [locationManager setDelegate:self]; // Not necessary in this case
    [locationManager startUpdatingLocation]; // Not neccessary in this case

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通过导入CoreLocation/CoreLocation.h和ImageIO/ImageIO.h标题以及相关框架，这些答案似乎都非常复杂。如果图像已保存到相机卷，并且您拥有ALAsset（从UIImagePicker或ALAssetLibrary），则可以获得如下元数据：

asset.defaultRepresentation.metadata;

如果您想将该图像从相机卷保存到另一个位置（例如在沙盒/文档中），只需执行以下操作：

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);

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我使用这种方法从图像中获取exifdata字典，我希望这也能对您起作用

-(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]);


    }

}

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你能告诉我获取exif数据后如何保存图像吗？请告诉我什么是“桥”在您的代码中？：-）@Marvin我使用的是ARC。

\uuuu bridge

是一手关键字之一，它告诉ARC对象的所有权，以便它可以正确地清理它们。最简单的情况是

\uuu bridge

强制转换，ARC不会为其做任何额外的工作（它假设您自己处理对象的内存）。缓冲区的内存是否释放过？怀疑没有…？注意：您还需要包括#导入currentLatitude从何而来？您是在调用UIImagePicker之前通过标准CoreLocation调用进行设置，还是直接从返回的映像读取？调用UIImage之前的CoreLocation调用PickerControllerahh，它可能不准确。您调用CoreLocation，调用UIImagePicker，然后在拍摄图像之前物理移动设备一段距离。您现在的纬度和经度不准确。Drat…但您也可以将距离过滤器设置为5米，因此如果使用moves，它将自动获取其当前位置。您实际上，您并没有从映像中获取EXIF数据，而是创建EXIF并将其添加到映像中。这实际上并没有回答问题。这是一种比2012年的答案更好的方法。它还返回比其他方法多得多的信息：它们不会返回存储在{TIFF}中的信息如型号、品牌、版权、艺术家等。这应该标记为答案！请参见此答案。这不是回答问题，这与主题无关。他没有问如何获取位置，而是需要将位置作为UIImage的元数据

asset.defaultRepresentation.metadata;

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);

-(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]);


    }

}