An unhandled exception of type 'Leadtools.RasterException' occurred in Leadtools.Codecs.dll

Question

I am using Lead Tool with c#. And Got error in below code. I pass this string base64String value from JS when I cropped Image and then convert it in c# in to Image with Base64ToImage function. So this is all complete code which I did.

private static Image Base64ToImage(string base64String)
    {
        Image img = null;
        // Convert Base64 String to byte[]
        byte[] imageBytes = Convert.FromBase64String(base64String);
        using (MemoryStream ms = new MemoryStream(imageBytes, 0, imageBytes.Length))
        {

            // Convert byte[] to Image
            ms.Write(imageBytes, 0, imageBytes.Length);
            img = System.Drawing.Image.FromStream(ms);
        }
        return img;
    }


public static void CropImage(string base64String)
    {
        Image img = Base64ToImage(base64String);
        using (MemoryStream ms = new MemoryStream())
        {
            img.Save(ms, ImageFormat.Bmp);
            ms.Seek(0, System.IO.SeekOrigin.Begin);
            using (RasterCodecs codecs = new RasterCodecs())
            {
                // Load the source image from disk
                using (RasterImage image = codecs.Load(ms))
                {
                    // Crop 100 pixels from each side of the image
                    CropCommand command = new CropCommand();
                    command.Rectangle = new LeadRect(
                       left,
                       top,
                       width,
                       height);
                    command.Run(image); 
                    // Save it to disk
                    codecs.Save(image, output, RasterImageFormat.Bmp, 24);
                }
            } 
        }
    }

An unhandled exception of type 'Leadtools.RasterException' occurred in Leadtools.Codecs.dll

Anyone please give my some solution for this.

Answer 1

With LEADTOOLS 19, a license (eval or release) must be specified with the application before any LEADTOOLS features are used. If you haven't provided one, this is why you're getting the "Kernel has expired" message. If you have provided a license, check to see if it's still valid. If not, please contact the LEADTOOLS Sales team to get a valid license.

I couldn't get your code to work exactly as-is because I don't know how your Base64ToImage() method is returning an Image. In lieu of this, I took a more direct approach, and just loaded a file from disk to memory. This loads without any problem.

   class Program
   {
      static void Main(string[] args)
      {
         RasterSupport.SetLicense(@"C:\LEADTOOLS 19\Common\License\LEADTOOLS.LIC",
                                 File.ReadAllText(@"C:\LEADTOOLS 19\Common\License\LEADTOOLS.LIC.KEY"));

         Byte[] imageData = File.ReadAllBytes(@"C:\Users\Public\Documents\LEADTOOLS Images\cannon.jpg");

         using (MemoryStream ms = new MemoryStream(imageData))
         {
            // Put the pointer back to the beginning
            ms.Seek(0, System.IO.SeekOrigin.Begin);

            using( RasterCodecs codecs = new RasterCodecs())
            {
               // Load the source image from disk
               using (RasterImage image = codecs.Load(ms))  // on this line I got error...
               {
                  //do something with the image
               }
            }
         }
      }
   }

Since this works, it's possible the problem is within how you're creating the memory stream or what is in the memory stream. I recommend using the File.WriteAllBytes() method after creating your memory stream, and then read the file from disk. If this works, then the issue is in reading the memory stream. Typically this would mean the MemoryStream's position is not at the beginning. The code you have accounts for that though, so it's likely an issue with the data in the memory stream.