添加和读取图片的exif信息

添加经纬度信息和自定义字段

#import <ImageIO/ImageIO.h>

- (NSData *)addExifDataToImage:(NSData *)imageData withLatitude:(double)latitude longitude:(double)longitude customField:(NSString *)customFieldValue {
    // 创建图片数据源
    CGImageSourceRef source = CGImageSourceCreateWithData((CFDataRef)imageData, NULL);

    // 获取图片属性字典
    CFDictionaryRef properties = CGImageSourceCopyPropertiesAtIndex(source, 0, NULL);

    // 创建新的 EXIF 信息字典
    NSMutableDictionary *exifDictionary = [NSMutableDictionary dictionaryWithDictionary:(__bridge NSDictionary *)CFDictionaryGetValue(properties, kCGImagePropertyExifDictionary)];

    // 设置经纬度信息
    [exifDictionary setObject:[NSNumber numberWithDouble:latitude] forKey:(NSString *)kCGImagePropertyGPSLatitude];
    [exifDictionary setObject:[NSNumber numberWithDouble:longitude] forKey:(NSString *)kCGImagePropertyGPSLongitude];

    // 添加自定义字段
    [exifDictionary setObject:customFieldValue forKey:@"MyCustomField"];

    // 将新的 EXIF 信息字典添加到图片属性字典中
    CFMutableDictionaryRef mutableProperties = CFDictionaryCreateMutableCopy(NULL, 0, properties);
    CFDictionarySetValue(mutableProperties, kCGImagePropertyExifDictionary, (__bridge CFDictionaryRef)exifDictionary);

    // 创建图片数据目标
    CGImageDestinationRef destination = CGImageDestinationCreateWithData((CFMutableDataRef)[NSMutableData data], (CFStringRef)CGImageSourceGetType(source), 1, NULL);

    // 将图片数据添加到目标对象中，并传入修改后的属性字典
    CGImageDestinationAddImageFromSource(destination, source, 0, (__bridge CFDictionaryRef)mutableProperties);

    // 完成写入操作
    BOOL success = CGImageDestinationFinalize(destination);

    // 获取修改后的图片数据
    NSData *updatedImageData = nil;
    if (success) {
        updatedImageData = (__bridge_transfer NSData *)CGImageDestinationCopyData(destination, 0);
    }

    // 释放资源
    CFRelease(source);
    CFRelease(properties);
    CFRelease(mutableProperties);
    CFRelease(destination);

    return updatedImageData;
}

读取exif信息

NSURL *imageFileURL = [NSURL fileURLWithPath:@"/Users/USERNAME/Documents/tasting_menu_004.jpg"];
CGImageSourceRef imageSource = CGImageSourceCreateWithURL((CFURLRef)imageFileURL, NULL);
NSDictionary *treeDict;
NSMutableString *exifData;

NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
                         [NSNumber numberWithBool:NO], (NSString *)kCGImageSourceShouldCache,
                         nil];

CFDictionaryRef imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, ( CFDictionaryRef)options);
CFRelease(imageSource);
if (imageProperties) {
    treeDict = [NSDictionary dictionaryWithDictionary:(NSDictionary*)(imageProperties)];
    id exifTree = [treeDict objectForKey:(NSString *)kCGImagePropertyExifDictionary];

    exifData = [NSMutableString stringWithString:@""];

    for (NSString *key in [[exifTree allKeys] sortedArrayUsingSelector:@selector(compare:)]) {
        NSString* locKey = [[NSBundle bundleWithIdentifier:@"com.apple.ImageIO.framework"] localizedStringForKey:key value:key table: @"CGImageSource"];
        id  value = [exifTree  valueForKey:key]  ;

        [exifData appendFormat:@"key =%@ ; Value = %@ \n", locKey,value];
    }
    NSLog(@" exifData %@", exifData);
}