Question

Here’s the deal. I’m trying to use a function to compress an image from my notebook camera while using a standard code to do that:

    public static byte[] EncodeImage(this Image image)
    {
        using (MemoryStream ms = new MemoryStream())
        {
            ImageCodecInfo jpegCodec = GetEncoderInfo("image/jpeg");
            EncoderParameter qualityParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 80);
            EncoderParameters encoderParams = new EncoderParameters(1);
            encoderParams.Param[0] = qualityParam;

            image.Save(ms, jpegCodec, encoderParams);
            return ms.ToArray();
        }
    }

After the compression is done, I save it to the database. Works good, providing me with a good amount of compression (500 000 bytes vs 32 000). Some time later, I need to show the image to the user in a winforms application.

using (MemoryStream ms = new MemoryStream(entity.Photo))
    fotoPictureBox.Image = Image.FromStream(ms);

Again, this displays a nice image. However, then I want the user to be able to download the image and save where he sees suitable. And this is when all the problems arise.

If I use this code:

fotoPictureBox.Image.Save(imageSaveFileDialog.FileName);

I receieve a typical generic GDI+ error.
If I try to save the image by using the code I’ve encoded it

     public static void SaveEncodedImage(this Image image, string targetPath)
    {
        ImageCodecInfo jpegCodec = Pomocne.GetEncoderInfo("image/jpeg");
        EncoderParameter qualityParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 80);
        EncoderParameters encoderParams = new EncoderParameters(1);
        encoderParams.Param[0] = qualityParam;

        image.Save(targetPath, jpegCodec, encoderParams);
    }

I get this error (pointing to the line image.Save(targetPath, jpegCodec, encoderParams);):

An unhandled exception of type System.ArgumentException occurred in System.Drawing.dll
Additional information: Parameter is not valid.

Can please anyone help? It’s rather urgent, thank you.

To address some questions/answers you will probably start with – if I don’t compress the image with this code, I can save the image to the chosen path without any problems. So there’s clearly some problem with decoding or something like that. Don’t ask me if I have sufficient permissions, because I have.

Answer 1

For some reason this code works great:

File.WriteAllBytes(targetPath, byteArray);

I guess sometimes the easiest solution is the right one. Not sure about the exact explanation (you can provide one, I’ll surely vote up), but this is resolved.
Thanks anyway.