iOS 图片压缩

       //压缩
        NSData *imageData = UIImageJPEGRepresentation(image, 0.00001);
        
        // 获取沙盒目录
        NSString *fullPath = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"/small.png"];
        
        // 将图片写入文件
        [imageData writeToFile:fullPath atomically:NO];