Error converting byte array to image and trying to save

Question

I receive the below error when trying to save an image which is converted from a byte array and not too sure why. Unfortunately, the error doesn't provide much detail on what the actual problem is. Error and code below

Error:

Exception Details: System.Runtime.InteropServices.ExternalException: A generic error occurred in GDI+.

and code:

byte[] imageBytes = Convert.FromBase64String(base64string);
Image image;
MemoryStream ms = new MemoryStream(imageBytes);
image = Image.FromStream(ms);
image.Save("testImage.png", System.Drawing.Imaging.ImageFormat.Png);

EDIT: this error is thrown on the image.Save line

Possible duplicate of [How to find reason for Generic GDI+ error when saving an image?](http://stackoverflow.com/questions/15571022/how-to-find-reason-for-generic-gdi-error-when-saving-an-image) — djv, Apr 12 '16 at 15:31
Try disposing of the `MemoryStream` object before saving the image in case it holds a lock on it — TheLethalCoder, Apr 12 '16 at 15:31
@Verdolino I tried converting to a bitmap before saving it, the same error occurs — GregH, Apr 12 '16 at 15:36
@TheLethalCoder this does not solve the issue, same error occurs — GregH, Apr 12 '16 at 15:37
@peggy there are many other solutions on that page. Make sure you have exhausted them all. — djv, Apr 12 '16 at 15:40
Do you/your application have write permission to the folder it's in? In the _Program Files_ folders you usually don't. — Visual Vincent, Apr 12 '16 at 16:25

score 1 · Accepted Answer · answered Apr 12 '16 at 15:50

I created a small test method like your code that looks like the below:

using (System.IO.MemoryStream ms = new System.IO.MemoryStream())
{
    image.Save(ms, System.Drawing.Imaging.ImageFormat.Tiff);
    string base64String = Convert.ToBase64String(ms.ToArray());

    //Your code
    byte[] imageBytes = Convert.FromBase64String(base64String);
    System.IO.MemoryStream ms2 = new System.IO.MemoryStream(imageBytes);
    image = Image.FromStream(ms2);
    image.Save("testImage.tif", System.Drawing.Imaging.ImageFormat.Tiff);
}

The only difference from my code to yours is that it uses a .tif image as input to get the base64String.

When I have tested this it works fine with no error, therefore I suggest you check a few things:

The application has Read and Write permissions to the current directory
The testImage.png is not locked by another process
The base64String is valid and not providing errors
The image when loaded looks fine, i.e. display it in a PictureBox if your application runs in WindowsForms

Error converting byte array to image and trying to save

1 Answers1