ios - 优化从相机胶卷中选取的图像以减小文件大小

Question

在我的应用程序中，如果用户从相机胶卷中选择一张图像用作公司 Logo (添加到最终的 pdf 中)，在某些情况下，附加文件的大小可能从 8mb(没有图像)到 29mb。当用户通过电子邮件发送文件时，这是一个问题，因为它比大多数服务器允许的附件大小要大

- (IBAction)schemeLogoPressed:(id)sender {
 LogCmd();
    UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
    imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    imagePicker.delegate = self;
    imagePicker.allowsEditing = NO;
    [self.editController presentModalViewController:imagePicker animated:YES];
   }    

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
 {
    DebugLog(@"info dict: %@", info);
    [picker dismissModalViewControllerAnimated:YES];
    UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
    self.schemeLogo.backgroundColor = [UIColor whiteColor];
    self.schemeLogo.image = image;
    NSData *imageData1 = UIImagePNGRepresentation(image);
    NSString *path1 = [ICUtils pathForDocument:@"schemeLogo.png"];
    [imageData1 writeToFile:path1 atomically:NO];

我可以做些什么来优化选取的图像大小吗？

Answer 1

改变这一行:

NSData *imageData1 = UIImagePNGRepresentation(image);

到:

NSData *imageData1 = UIImageJPEGRepresentation(image, 0.9f);

第二个参数(0.9 float )是质量。数字越大，质量越高。从 0.0 到 1.0