Issue with populating Bitmap Object in Visual Studio 2015

I'm having issues displaying a Bitmap to a PictureBox in Visual Studio C++. To simplify things, I just want to create a gradient that is displayed in a PictureBox. However, I get these periodic black streaks through the image. I get these even if I set all the byte values to 255. imageWidth is 640 and imageHeight is 480. In the tempImage assignments, I have tried both creating a simple gradient and assigning all pixels to white (255). Any help would be greatly appreciated. tempImage = new unsigned char *[imageHeight]; for (int count = 0; count < imageHeight; ++count) { tempImage[count] = new unsigned char[imageWidth * 3]; } // populate image int i, j; for (i = 0; i < imageHeight; ++i) { for (j = 0; j < imageWidth; ++j) { tempImage[i][j * 3] = 255; // i * 255 / imageHeight; tempImage[i][j * 3 + 1] = 255; // i * 255 / imageHeight; tempImage[i][j * 3 + 2] = 255; // i * 255 / imageHeight; } } Bitmap ^mybm = gcnew Bitmap(imageWidth, imageHeight, imageWidth * sizeof(unsigned char) * 3, Imaging::PixelFormat::Format24bppRgb,(IntPtr) tempImage); this->SImage->Image = mybm; this->SImage->Show();