objective-c - ios-在uiimage元数据中添加地理位置

先生，
    在这里，我需要从元数据到uiimage中添加地理位置，但是在添加之后，我仅将其加载到相册中，但是在这里，我需要该图像，在此我添加了源代码

- (void) saveImage:(UIImage *)imageToSave withInfo:(NSDictionary *)info
{
    ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];


        // Get the image metadata (EXIF & TIFF)
    NSUserDefaults *defaults=[NSUserDefaults standardUserDefaults];
    [defaults objectForKey:latkey];
    float longitude=[defaults floatForKey:longkey];
    float latitude=[defaults floatForKey:latkey];
    CLLocation * loc=[[CLLocation alloc] initWithLatitude:latitude longitude:longitude];
    NSMutableDictionary *metaDict = nil;
    if ([info objectForKey:UIImagePickerControllerOriginalImage] != nil) {
        metaDict = [NSMutableDictionary dictionaryWithDictionary:[info objectForKey:UIImagePickerControllerMediaMetadata]];
        NSDictionary *gpsDict = [self currentLocation:loc];
        if ([gpsDict count] > 0) {
            [metaDict setObject:gpsDict forKey:(NSString*)kCGImagePropertyGPSDictionary];
        }
    }
    [library writeImageToSavedPhotosAlbum:[imageToSave CGImage] metadata:metaDict completionBlock:^(NSURL *newURL, NSError *error) {
        if (error) {

        } else {
        }
    }];

    NSLog(@"metaDict  :%@",metaDict);


    NSURL *referenceURL = [info objectForKey:UIImagePickerControllerReferenceURL];
    [library assetForURL:referenceURL resultBlock:^(ALAsset *asset) {
        ALAssetRepresentation *rep = [asset defaultRepresentation];
        NSDictionary *metadata = rep.metadata;
        NSLog(@"%@", metadata);

        CGImageRef iref = [rep fullScreenImage] ;

        if (iref) {
            capturedImage.image = [UIImage imageWithCGImage:iref];
        }
    } failureBlock:^(NSError *error) {
            // error handling
    }];
}

为当前地理位置创建一个EXIF字段。

- (NSMutableDictionary*)currentLocation:(CLLocation *)location{
    NSMutableDictionary *locDict = [[NSMutableDictionary alloc] init];

    if (location != nil) {
        CLLocationDegrees exifLatitude = location.coordinate.latitude;
        CLLocationDegrees exifLongitude = location.coordinate.longitude;

        [locDict setObject:location.timestamp forKey:(NSString*)kCGImagePropertyGPSTimeStamp];

        if (exifLatitude < 0.0) {
            exifLatitude = exifLatitude*(-1);
            [locDict setObject:@"S" forKey:(NSString*)kCGImagePropertyGPSLatitudeRef];
        } else {
            [locDict setObject:@"N" forKey:(NSString*)kCGImagePropertyGPSLatitudeRef];
        }
        [locDict setObject:[NSNumber numberWithFloat:exifLatitude] forKey:(NSString*)kCGImagePropertyGPSLatitude];

        if (exifLongitude < 0.0) {
            exifLongitude=exifLongitude*(-1);
            [locDict setObject:@"W" forKey:(NSString*)kCGImagePropertyGPSLongitudeRef];
        } else {
            [locDict setObject:@"E" forKey:(NSString*)kCGImagePropertyGPSLongitudeRef];
        }
        [locDict setObject:[NSNumber numberWithFloat:exifLongitude] forKey:(NSString*) kCGImagePropertyGPSLongitude];
    }

    return [locDict autorelease];
}

请帮我

最佳答案

编辑：U可以通过按this链接来将图像添加到相册中。

现在，如果您拥有资产，则可以使用资产的创建日期，在添加到相册之前，可以知道最后添加的这样的照片作为保存日期：

NSDate *imgCreateddate = [asset valueForProperty:ALAssetPropertyDate];
if(imgCreateddate isGreaterThan savedDate)
{
  last Photo;
}

请参考Adding metadata to iOS images the easy way链接。

有关示例代码，请参见GusUtils。

请参考saving-geotag-info-with-photo链接