从 UIImage 获取 Exif 数据 - UIImagePickerController [英] Get Exif data from UIImage - UIImagePickerController

问题描述

如何从 UIImagePickerController 中选择的 UIImage 中获取 Exif 信息?

How can we get Exif information from UIImage selected from UIImagePickerController?

我为此做了很多研发，得到了很多回复，但仍然未能实现.

I had done much R&D for this and got many replies but still failed to implement this.

我经历过这个这个和这个链接

请帮我解决这个问题.

提前致谢..

推荐答案

我找到了解决方案并从 此处

I had found solution and got answer from here

从这里我们也可以获取 GPS 信息..

From here We can get GPS info as well..

太棒了，感谢大家帮助我解决这个问题.

Amazing and thanks all for helping me to solve this problem.

更新

这是我自己创建的另一个函数，也返回 Exif 数据和 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.并为此使用当前的纬度和经度.所以必须使用 CoreLocation.framework

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;
}

我们将像这样检索数据

//FOR CAMERA IMAGE
NSData *originalImgData = [self getImageWithMetaData:imgOriginal];

//FOR PHOTO LIBRARY IMAGE
[self getImagedataPhotoLibrary:[[myasset defaultRepresentation] metadata] andImage:imgOriginal];

对于所有这些，您应该导入 AssetsLibrary.framework 和 ImageIO.framework.

For all of this you should have to Import AssetsLibrary.framework and ImageIO.framework.

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