Apply a gradient map to an image
Replace a photo's tones with a gradient between two colors of your choice, distributed according to each pixel's brightness — a duotone effect widely used in design and art photography.
How it works
A gradient map first calculates the brightness of each pixel in the image (regardless of its original color), then replaces that value with the matching color from a two-tone gradient: the "shadows" color for dark areas, the "highlights" color for light areas, with a gradual blend between the two for midtones.
Which colors should I choose for a successful duotone effect?
A strong contrast between a dark, saturated hue (midnight blue, purple, brown) for the shadows and a warm light hue (yellow, orange, off-white) for the highlights usually gives the best result, close to the posters and album covers that popularized this effect.
Does the result depend on the photo's original colors?
No, only the brightness (a weighted mix of red, green and blue) is taken into account: two photos with very different colors but similar brightness will give a very similar result with the same gradient settings.
100% local processing: the gradient is calculated entirely in your browser using JavaScript — your photo is never sent to a server.