Using Older Versions of System.Drawing with IronOCR

Updated: August 2, 2026

.NET 4.6.1 to .NET 4.8 projects come with a built-in System.Drawing version 4.0.0. This version of System.Drawing is out of support and may contain vulnerable code.

Trying to instantiate OcrInput from System.Drawing.Image will throw "IronOcr.Exceptions.IronOcrProductException: 'Unable to parse Object [] as a valid image file.'". This is because IronOCR could not recognize System.Drawing.Image as a valid input type.

Error Screenshot

Trying to specify Image input type like OcrInput(Image: image) will throw a "cannot convert from System.Drawing.Image to SixLabors.ImageSharp.Image" error.

Conversion Error Screenshot

Possible Solutions

Update System.Drawing.Common to a current, supported version. The older version of System.Drawing is out of support and may contain vulnerable code.

Load the image with OcrInput.LoadImage, which accepts a file path, byte[], Stream, or IronSoftware.Drawing.AnyBitmap. In current IronOCR, OcrInput has a parameterless constructor and handles image loading internally, so you do not need SixLabors.ImageSharp or System.Drawing to prepare the input.

using IronOcr;

class Program
{
    static void Main()
    {
        var Ocr = new IronTesseract();

        // Load the image directly with IronOCR
        using (var Input = new OcrInput())
        {
            Input.LoadImage("image.jpg");

            // Perform OCR on the input
            var Result = Ocr.Read(Input);

            // Print the recognized text
            Console.WriteLine(Result.Text);
        }
    }
}

using IronOcr;

class Program
{
    static void Main()
    {
        var Ocr = new IronTesseract();

        // Load the image directly with IronOCR
        using (var Input = new OcrInput())
        {
            Input.LoadImage("image.jpg");

            // Perform OCR on the input
            var Result = Ocr.Read(Input);

            // Print the recognized text
            Console.WriteLine(Result.Text);
        }
    }
}

The above code initializes an instance of IronTesseract, loads an image from a file with OcrInput.LoadImage, and then processes the image with IronOCR to extract text.

Curtis Chau

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Technical Writer

Curtis Chau holds a Bachelor’s degree in Computer Science (Carleton University) and specializes in front-end development with expertise in Node.js, TypeScript, JavaScript, and React. Passionate about crafting intuitive and aesthetically pleasing user interfaces, Curtis enjoys working with modern frameworks and creating well-structured, visually appealing manuals.

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