GIMP: Selective Colouring

Gimp. GnuImageMnipulationProgram. An open source paint and image editing program for Unix, X Window and Mac OS X. Sometimes looked at as a free replacement of some good commercial photo editing programs like photoshop.
You must have seen a black and white photograph with some part in colour. For example in an advertisement of lipstick, all except lips can be seen in true colours.
There are two approaches possible to achieve this. This technique is also known as "hand colouring".
Method 1:Take original colour image, duplicate it, convert the duplicate to black and white, and paste it as a new layer on top of the color image. Add an opaque layer mask and then selectively paint transparency into the upper mask, exposing the colour area underneath.
Method 2:Convert background layer to grayscale, make the top layer active and set its mode to colour. Everywhere you brush, your color image will become uncolored. Keep brushing away those areas you want to "remove"

Let's see the 1st method above, with an example.

[Please click to enlarge the images below]

STEP1:
Load the colour image into GIMP.
File>Open>"the image"

STEP2:
a]Duplicate the image --> Ctrl+D
and
b]convert it to grayscale then RGB: -->
Image>Mode>Grayscale and then Image>Mode>RGB

STEP3
Go to original colour image window. Open Layers dialogue[Ctrl+L].
Right clicking on the background layer[containing our original image] add new layer. Name it as BnW. Change the layer fill type to "Transparent". Click OK.

STEP4:
Go to the BnW image and select all, then copy [Ctrl+A then Ctrl+C]. Then go to the colour image window and paste [Ctrl+V].
Open Layers dialogue again[Ctrl+L]. You can see pasted layer as a Floating Selection. Keep "Opacity" 100% and click on "Anchor" at the bottom.

STEP5:
Right click on the BnW and add new layer mask [white]with full opacity.

STEP6:
Make sure that Black is selected as the foreground color in the main toolbox. We' will now paint transparency into the layer mask to reveal the colour image below it. Select any suitable brush from brushes dialogue[Ctrl+Shift+B].

Done!
Begin painting interior parts of the image that you wish to see with colours. Rest of the parts will remain black and white. Zooming into the image or selecting different type of brush during hand paintaing can be given a try for better results.


The original and selectively coloured images: