How to find reason for Generic GDI+ error when saving an image?

Question

Having a code that works for ages when loading and storing images, I discovered that I have one single image that breaks this code:

const string i1Path = @"c:\my\i1.jpg";
const string i2Path = @"c:\my\i2.jpg";

var i = Image.FromFile(i1Path);
i.Save(i2Path, ImageFormat.Jpeg);

The exception is:

System.Runtime.InteropServices.ExternalException occurred

A generic error occurred in GDI+.

at System.Drawing.Image.Save(String filename, ImageCodecInfo encoder, EncoderParameters encoderParams)
at System.Drawing.Image.Save(String filename, ImageFormat format)
at ...

As far as I can see, there is nothing special about the image. It is approx 250 pixels in size and can be opened in e.g. Windows Image Viewer or Paint.NET:

(Since the image above, after being uploaded to Stack Overflow does not produce the error anymore, I've put the original image here)

What I discovered is that upon calling the Save method, the destination image file is being created with zero bytes.

I am really clueless on what causes the error.

My questions:

• Can you think of any special thing that would hinder .NET from saving the image?
• Is there any way (beside panicing) to narrow down these kind of errors?

Answer 1

While I still did not find out the reason what exactly caused the error when saving the image, I found a workaround to apply:

const string i1Path = @"c:\my\i1.jpg";
const string i2Path = @"c:\my\i2.jpg";

var i = Image.FromFile(i1Path);

var i2 = new Bitmap(i);
i2.Save(i2Path, ImageFormat.Jpeg);

I.e. by copying the image internally into a Bitmap instance and saving this image instead of the original image, the error disappeared.

I'm assuming that by copying it, the erroneous parts the caused the original Save call to fail are being removed an/or normalized, thus enabling the save operation to succeed.

Interestingly, the so stored image has a smaller file on disk (16 kB) than its original source (26 kB).

Answer 2

First of all make sure, that the desired folder has Read/Write permissions. Changing the permissions solved this problem for me.

Answer 3

Solution is here, you must dispose image object to release the memory on the server. Try use using statement. Make sure destination directory on server exists too.

Answer 4

The reason may be that the image is loaded lazily and the loading process is not yet finished when you try to save it.

Following what's said in this blog post (assuming you're German by the picture you linked in your question) provides a possible solution. Also this SO question's accepted answer indicates this is due to the fact the image file you're trying to save to is locked.

EDIT
For Ulysses Alves, from the linked blog entry: If you load an image using Image.FromFile() it remains locked until it is disposed of. This prevents calls to Save().

pictureBox1.Image = Image.FromFile("C:\\test\\test1.jpg");
pictureBox1.Image.Save("C:\\test\\test2.jpg");

The above code throws an error.

To make it work, you need to copy the image. The following code works:

pictureBox1.Image = Image.FromFile("C:\\test\\test1.jpg");
Image copy = pictureBox1.Image;
copy.Save("C:\\test\\test2.jpg")

Answer 5

my solution was to make, write temp content (File.WriteAllText) just before saving the file

Here is the code:

var i = Image.FromFile(i1Path);
File.WriteAllText(i2Path, "empty");  // <---- magic goes here
i.Save(i2Path, ImageFormat.Jpeg);

Please try and let me know

Answer 6

I found this question because I also faced the similar error and the file was actually created with zero length (if you don't see any file, first check the permissions to write into folder as other answers suggest). Although my code was slightly different (I use stream to read the image from memory, not from file), I think my answer may be helpful to anyone facing similar problem.

It may looks counter-intuitive, but you can't really dispose memory stream until you finish with image.

NOT WORKING:

Image patternImage;

using (var ms = new MemoryStream(patternBytes)) {
    patternImage = new Bitmap(ms);
}

patternImage.Save(patternFile, ImageFormat.Jpeg);

Just don't dispose the stream until you done with image.

WORKS:

using (var ms = new MemoryStream(patternBytes)) {
    patternImage = new Bitmap(ms);
    patternImage.Save(patternFile, ImageFormat.Jpeg);
}

What is misleading:

• Error message doesn't really tell you anything
• You can see the image properties, like width and height, but can't save it

Answer 7

Open in the program

const string i1Path = @"c:\my\i1.jpg";

const string i2Path = @"c:\my\i2.jpg";

var i = Image.FromFile(i1Path);

i.Save(i2Path, ImageFormat.Jpeg);

i.Dispose();

Answer 8

Key Information:

// Using System.Drawing.Imaging:
new Bitmap(image).Save(memoryStream, ImageFormat.Jpeg);

You MUST Cast the Image to a Bitmap to Save it.

Using:

// Using System.Drawing.Imaging:
image.Save(memoryStream, ImageFormat.Jpeg);

WILL throw the Error:

Generic GDI+ error when saving an image