C#StorageFile图像调整大小为一定的字节数

时间:2016-12-27 11:39:29

标签: c# uwp bitmapimage storagefile

我已经在Stack上阅读了很多关于图像大小调整和质量降低的帖子,但其中没有关于降低某些物理磁盘空间质量的帖子

我有一个拍照的代码:

 import android.view.viewgroup.layoutparams;

现在我需要将数据发送到服务器,但在此之前,我需要确保照片不超过3 MB。

所以我这样做:

private async void TakeAPhoto_Click(object sender, RoutedEventArgs e)
{
    CameraCaptureUI captureUI = new CameraCaptureUI();
    captureUI.PhotoSettings.Format = CameraCaptureUIPhotoFormat.Jpeg;

    StorageFile photo = await captureUI.CaptureFileAsync(CameraCaptureUIMode.Photo);
    if (photo != null)
    {

    }
}

所以问题是关于ELSE阻止

有没有更好的,或者我错过了一些内置的方法,通过降低图像的质量来将图像调整到一定的兆字节数?

因为这样做:

BasicProperties pro = await photo.GetBasicPropertiesAsync();
if (pro.Size < 3072)
{
    // SEND THE FILE TO SERVER
}
else
{
    // DECREASE QUALITY BEFORE SENDING
}

看起来不太好。

1 个答案:

答案 0 :(得分:0)

只需创建一个功能:

    /// <summary>
    /// function to reduce image size and returns local path of image
    /// </summary>
    /// <param name="scaleFactor"></param>
    /// <param name="sourcePath"></param>
    /// <param name="targetPath"></param>
    /// <returns></returns>
    private string ReduceImageSize(double scaleFactor, Stream sourcePath, string targetPath)
    {
        try
        {
            using (var image = System.Drawing.Image.FromStream(sourcePath))
            {
                //var newWidth = (int)(image.Width * scaleFactor);
                //var newHeight = (int)(image.Height * scaleFactor);


                var newWidth = (int)1280;
                var newHeight = (int)960;

                var thumbnailImg = new System.Drawing.Bitmap(newWidth, newHeight);
                var thumbGraph = System.Drawing.Graphics.FromImage(thumbnailImg);
                thumbGraph.CompositingQuality = CompositingQuality.HighQuality;
                thumbGraph.SmoothingMode = SmoothingMode.HighQuality;
                thumbGraph.InterpolationMode = InterpolationMode.HighQualityBicubic;
                var imageRectangle = new System.Drawing.Rectangle(0, 0, newWidth, newHeight);
                thumbGraph.DrawImage(image, imageRectangle);
                thumbnailImg.Save(targetPath, image.RawFormat);
                return targetPath;



            }
        }
        catch (Exception e)
        {
            Console.WriteLine("Exception in ReduceImageSize" + e);
            return "";
        }
    }

然后在您的else块中调用此函数,如下所示,您将获得缩小尺寸的相同图像:

        string ImageLink = "https://imagesus-ssl.homeaway.com/mda01/337b3cbe-80cf-400a-aece-c932852eb929.1.10";
        string FinalTargetPath=@"F:\ReducedImage.png";
        HttpWebRequest imageRequest = (HttpWebRequest)WebRequest.Create(ImageLink);
        WebResponse imageResponse = imageRequest.GetResponse();
        Stream responseStream = imageResponse.GetResponseStream();

       string ImagePath= ReduceImageSize(0.5, responseStream, FinalTargetPath);