CODEWITHSUNDEEP
c#itextabstract-classsystem.drawing.imaging
Lars Hansen
Lars Hansen

Reputation: 153

Detect a corrupt image file

Hi All you clever guys,

Im faceing a bit of a challenge here. Im supposed to create several different PDF's containing multiple (not similar) images.

Unfortunately some of the images are corrupt/defect. This causes the creation of the partikular PDF to fail/dump.

Is there a way I can test the image prior to creation of the PDF?

Please be gentle with me. Im not an expert.

I found out that System.Drawings.Image can test some formats. Better than nothing I guess (it will reduce the subset significantly).

But when using iTextSharp.text.Image for the creation of the PDF's. Then I dont know how to use the System.Drawings.Image because when I try Image newImage = Image.FromFile("SampImag.jpg"); then it (Image) refers to the iTextSharp.text.Image class.

System.Drawings.Image is abstract, so I've tried to create a subclass.

public class ImageTest : System.Drawing.Image
    {

    }

Now I get the error message:"Error 1 The type 'System.Drawing.Image' has no constructors defined" Trying to investigate which constructors I can use gives me this attempt.

public class ImageTest : System.Drawing.Image
    {
      ImageTest(string filename);
      {
      }
    }

But this doesn't work.

Please inform me if there is information you need which is relevant to you for investigating this matter.

Thanks in advance.

Upvotes: 1

Views: 2470

Answers (2)

user6438653
user6438653

Reputation:

Catch OutOfMemoryException works:

try
{
    // Using System.Drawing.Image
    System.Drawing.Image img = (System.Drawing.Bitmap)System.Drawing.Image.FromFile("myimage.png");
}
catch (OutOfMemoryException ex)
{
    // Handle the exception...
}

I tested it with this code:

try
{
    System.Drawing.Image img = (System.Drawing.Bitmap)System.Drawing.Image.FromFile("myimage.png");
}
catch (OutOfMemoryException ex)
{
    Console.WriteLine("Error loading image...");
}

And I deleted a few characters in a .png file, and the console said:

Error loading image...

And to convert it into a iTextSharp.text.Image

Upvotes: 1

Ben Jackson
Ben Jackson

Reputation: 1138

You should just be able to use

public bool IsValidImageFile (string imageFile)
{
    try
    {
        // the using is important to avoid stressing the garbage collector
        using (var test = System.Drawing.Image.FromFile(imageFile))
        {
             // image has loaded and so is fine
             return true;
        }
    }
    catch
    {
        // technically some exceptions may not indicate a corrupt image, but this is unlikely to be an issue
        return false;
    } 
}

Upvotes: 3

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