Watercolour is a painting technique that uses water-based paints. Artists such as Cézanne and Whistler both employed watercolour in some of their paintings. Using free image-editing software such as GIMP, you can convert digital photos into a picture that resembles a watercolour painting. This opens up new possibilities for displaying and sharing your favourite photos.
Open the picture that you want to convert to watercolour in GIMP. Click on the "File" menu, choose "Open," browse to the photo file and click "Open."
Select the image layer by clicking on it in the "Layers, Channels, Paths..." window.
Duplicate the layer. Click on the "Create a duplicate of the layer..." button below the list of layers in the "Layers, Channels, Paths..." window. Make sure the duplicate layer is selected.
Desaturate the duplicate layer. Click on the "Tools" menu, select "Color Tools" and then "Desaturate." Leave "Lightness" selected in the dialogue box and click "OK."
Click on the "Colors" menu and select "Curves." Leave the channel drop-down as "Value."
Click on and drag the diagonal line in the "Adjust Color Curves" window until you have the desired amount of grayscale. Click "OK" to save the settings.
Drag the original layer in the "Layers, Channels, Paths..." window so it is above the duplicate layer.
Change the mode of the original layer to "Color" in the "Mode" drop-down.
Save the modified image as a new file. Click on the "File" menu and choose "Save a copy."
Adjusting the colour curves may take several attempts, and settings will vary with the picture being adjusted.