Question

I am totally stuck on image resizing because I am getting OutOfMemoryException using the typical examples of image resizing that can be found on the many questions that feature OOMs.

I even tried DynamicImage, which can be found on Nuget, and this also threw an OutOfMemoryException.

Can anyone tell me how I can reduce the quality/size of an image in C#, without loading it into memory?

Edit: I want the c# equivalent to this, if there is one?

Edit: I give up with the typical methods of resizing, as I just can’t avoid OutOfMemoryExceptions on my live site, which is running on an old server.

Further Edit: My server’s OS is Microsoft Server 2003 Standard Edition

I can post examples of my code, but I’m trying to find a way around OutOfMemoryExceptions.

public static void ResizeImage(string imagePath, int imageWidth, int imageHeight, bool upscaleImage) {
      using (Image image = Image.FromFile(imagePath, false)) {
        int width = image.Width;
        int height = image.Height;
        if (width > imageWidth || height > imageHeight || upscaleImage) {

          image.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipX);
          image.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipX);

          float ratio = 0;
          if (width > height) {
            ratio = (float)width / (float)height;
            width = imageWidth;
            height = Convert.ToInt32(Math.Round((float)width / ratio));
          }
          else {
            ratio = (float)height / (float)width;
            height = imageHeight;
            width = Convert.ToInt32(Math.Round((float)height / ratio));
          }

          using (Bitmap bitmap = new Bitmap(width, height)) {
            bitmap.SetResolution(image.HorizontalResolution, image.VerticalResolution);
            using (Graphics graphic = Graphics.FromImage(bitmap)) {

              graphic.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
              graphic.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
              graphic.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
              graphic.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
              graphic.DrawImage(image, 0, 0, width, height);

              string extension = ".jpg"; // Path.GetExtension(originalFilePath);

              using (EncoderParameters encoderParameters = new EncoderParameters(1)) {
                encoderParameters.Param[0] = new EncoderParameter(Encoder.Quality, 100L);
                using (MemoryStream imageMemoryStream = new MemoryStream()) {
                  bitmap.Save(imageMemoryStream, GetImageCodec(extension), encoderParameters);
                  using (Image result = Image.FromStream(imageMemoryStream, true, false)) {
                    string newFullPathName = //path;
                    result.Save(newFullPathName);
                  }
                }
              }
            }
          }
        }
      }
        }

I also tried this code as I hoped GetThumbnailImage would reduce the picture quality/size for me, but this is also throwing an OOM exception:

viewModel.File.SaveAs(path);
        Image image = Image.FromFile(path);
        Image thumbnail = image.GetThumbnailImage(600, 600, null, new IntPtr());
        image.Dispose();
        File.Delete(path);
        thumbnail.Save(path);
        thumbnail.Dispose();

Again, both my code examples work for me in my local machine, so I am not trying to find faults/fixes in the code as they should be fine. I’m looking for any solution to avoid the OOM exceptions, I had the idea of reducing the fize size somehow without loading the image into memory, but any alternative ideas that can help me would be appreciated.

Answer 1

I failed to mention that I inherited legacy code that was not disposing of images properly, because I did not think it was relevant since fixing it. The strange thing is, after restarting the website and the AppPool, I was able to upload pictures again without getting an OutOfMemoryExcepiton. I’m struggling to understand why this happened as I have changed the code to dispose of images properly and have done several deploys since, so I would expect that to clear any undisposed images from memory? All the code for picture resizing and uploading was in a static class and I believe that GC.collect() does not work on static variables?

My theory is that the undisposed images have built up in memory and have remained even when I have redepolyed to the site, as that’s the only conclusion I can reach since the code began working again after restarting the app pool.

I would delete my question but it has been answered now, happy to reassign the answer if anyone can help explain what was going on here.