c# - Large black line appears when printing bmp files using the EPL2 print language

Question

This is the 3rd part to this topic. Part 1, Part 2..

I was successfully able to print my monochrome bitmap to my printer, however there is a large black stripe along the right of the image when the item prints.

Here is the original

(Scanned in)What the printer printed

Code to generate binary blob

Rectangle rect = new Rectangle(0, 0, Bitmap.Width, Bitmap.Height);
System.Drawing.Imaging.BitmapData bmpData = null;
byte[] bitVaues = null;
int stride = 0;
try
{
    bmpData = Bitmap.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadOnly, Bitmap.PixelFormat);
    IntPtr ptr = bmpData.Scan0;
    stride = bmpData.Stride;
    int bytes = bmpData.Stride * Bitmap.Height;
    bitVaues = new byte[bytes];
    System.Runtime.InteropServices.Marshal.Copy(ptr, bitVaues, 0, bytes);
}
finally
{
    if (bmpData != null)
        Bitmap.UnlockBits(bmpData);
}

string str = String.Format("GW{0},{1},{2},{3},", X, Y, stride, Bitmap.Height);
byte[] ascii = Encoding.ASCII.GetBytes(str);
byte[] buffer = new byte[ascii.Length + bitVaues.Length + 1];
Buffer.BlockCopy(ascii, 0, buffer, 0, ascii.Length);
Buffer.BlockCopy(bitVaues, 0, buffer, ascii.Length, bitVaues.Length);
buffer[buffer.Length - 1] = (byte)'
';
return buffer;

My initial theory is the BMP format is adding that line as a end of line marker and is not viable when rendered. I am thinking I may have to reparse the file after I have the binary array and take out the 00 00 00 at the end of every line. But I am posting here in case anyone thinks of a better way.

Answer 1

Microsoft bitmaps are always padded to an even 32 bits. When you generate the bitmap, round the width up to a multiple of 32 and you should be fine.