Image Processing in C# - A smart solution ?

Question

I have an image with letters in it, the letters are in two colors black and blue, I want to read the blue colored letters from the image.

Can anyone suggest me a method to do this in C#. Iam studying GDI+,but still didn't get any logic to develop this program..

I tried OCRing it, but the issue with common OCRs is that they dont recognize the color difference.

I only want to read the Blue characters....

Any guidance is highly appreciated.

Answer 1

Step 1 -- set all black pixels to white

Step 2 -- set all blue pixels to blue

Step 3 -- OCR it

?

Regards

Mark

Answer 2

Try this one ;) But that's unsafe code.

void RedAndBlue()
{

    OpenFileDialog ofd;
    int imageHeight, imageWidth;

    if (ofd.ShowDialog() == DialogResult.OK)
    {
     Image tmp = Image.FromFile(ofd.FileName);
     imageHeight = tmp.Height;
     imageWidth = tmp.Width;
    }
    else
    {
     // error
    }

    int[,] bluePixelArray = new int[imageWidth, imageHeight];
    int[,] redPixelArray = new int[imageWidth, imageHeight];
    Rectangle rect = new Rectangle(0, 0, tmp.Width, tmp.Height);
    Bitmap temp = new Bitmap(tmp);
    BitmapData bmpData = temp.LockBits(rect, ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
    int remain = bmpData.Stride - bmpData.Width * 3;
    unsafe
    {
     byte* ptr = (byte*)bmpData.Scan0;
     for (int j = 0; j < bmpData.Height; j++)
     {
      for (int i = 0; i < bmpData.Width; i++)
      {
       bluePixelArray[i, j] = ptr[0];
       redPixelArray[i, j] = ptr[2];
       ptr += 3;
      }
      ptr += remain;
     }
    }
    temp.UnlockBits(bmpData);
    temp.Dispose();
}

Answer 3

You could probably modify the palette to have only black and white on the image