Problem with drawing on B&w or Gray TIFF using GDI+

Question

Problem with GDI+ in Visual C++ 6.0 Hello there, I'm using Visual C++ 6 with Platform SDK and trying to create a imaging program. The program is simple, where i the user can draw lines on a TIFF image. I'm using GDI+ for this purpose, but having one problem. The problem is that GDI+ just cannot draw on gray(8-bit)/black & white TIFF images or BMP for that matter. I dont know why. A simple test code is given below, void CGDIPlusDlg::OnButton8() { //gets current DC CDC *pDC=this->GetDC(); //gets Handle to DC HDC hdc=pDC->GetSafeHdc(); //Opens an image from disk Image img(L"c:\\mspaint.tif"); //target rectangle at coordinate 0,0 sizwe RectF r(0, 0, 100, 100); //Set graphics, and dest Graphics gr(hdc); RectF destRect(0, 0, 100, 100); //Draw original image-works fine gr.DrawImage(&img,destRect); //Create a blackpen (A,b,g,r), thickness 3 Pen blackPen(Color(255, 0, 0, 0), 3); //Start and end point PointF point1(0, 0); PointF point2(100.0f, 100.0f); //Draw line on image---doesnt work for BW images!! Graphics gr2(&img); gr2.DrawLine(&blackPen,point1,point2); RectF destRect2(100, 0, 100, 100); gr.DrawImage(&img,destRect2); } The image is created using MSPaint. Create a 100x100 image, draw something, and save as TIF. Save again by changing the image depth to black & white from the Image->Attributes menu. The program supposed to draw a diagonal line across the image, but it doest for the black&white version of tif. So, my problem is how to overcome this? Or, how can i programmatically convert a BW TIFF to color and work on it using GDI+? Oh yeah, can anyone try if this code works fine in C# or managed C++? Thanks, Usman