Objective-c - The image obtained by PHImageManager is blurry

Question

PHImageManager method- (PHImageRequestID)requestImageForAsset:(PHAsset *)asset targetSize:(CGSize)targetSize contentMode:(PHImageContentMode)contentMode options:(nullable PHImageRequestOptions *)options resultHandler:(void (^)(UIImage *__nullable result, NSDictionary *__nullable info))resultHandler; The image obtained is blurry, please solve it?