Draw image on top of another image with blending mode color

Question

In Photoshop you can select \"Color\" (the second from the bottom) to set the blending mode to the next lower layer:

Answer 1

Here's a safe (and slower) version of the accepted answer for completeness.

        using (var lower = new Bitmap(@"lower.png"))
        using (var upper = new Bitmap(@"upper.png"))
        using (var output = new Bitmap(lower.Width, lower.Height))
        {
            var width = lower.Width;
            var height = lower.Height;

            for (var i = 0; i < height; i++)
            {
                for (var j = 0; j < width; j++)
                {
                    var upperPixel = upper.GetPixel(j, i);
                    var lowerPixel = lower.GetPixel(j, i);

                    var lowerColor = new HSLColor(lowerPixel.R, lowerPixel.G, lowerPixel.B);
                    var upperColor = new HSLColor(upperPixel.R, upperPixel.G, upperPixel.B) {Luminosity = lowerColor.Luminosity};
                    var outputColor = (Color)upperColor;

                    output.SetPixel(j, i, outputColor);
                }
            }

            // Drawing the output image
        }