The history brush is a really neat tool in Photoshop. It allows you to return a portion of your image to a previous step in the history of your photo editing. I can think of all sorts of uses for this, especially if you do a lot of photo editing. The easiest way to demonstrate it is to selective colour, but once you know how to use it I'm sure you will find other uses for it too.
I apologize if this tutorial doesn't work well for programs other than Photoshop.
First, open an image for editing. Duplicate it, and desaturate the top layer. For caution sake, save it with a different file name so you aren't editing the original file.
From your left menu, select the history brush:
Now choose a brush. I like to use a soft edged brush, as I find it more forgiving around the edges. Start with a size that will allow you to do some fairly careful work on the image. My image started big so I chose 65 to start. You also can see that you can change the mode and brush opacity - you can experiment with your history brush on different modes (lighten, darken, pin light, etc) and different opacities to get different looks. For this simply tutorial I'm leaving it at 100% and on normal mode.
Now go back to your image. Bring up the history. You will see that to the left of each step in your history, there is a little empty box. Click the box next to the step in the process that you want to revert the image to. For recolouring, that is the step right before desaturating. Now you will see the history brush icon in that box. You are telling the program that this is the step you'd like to revert the image to when you use the brush.
Keep the desaturated layer active in the layers palette, and begin brushing on the photo. You will see where you brush the colour comes back - the image is reverting to the point in the history that you selected.
Continue brushing over the entire area of the image you want coloured. You may need to change your brush size to get into smaller corners. If you make a mistake (like I did, going out of the lines), you can use the history brush again, this time set on the step in the history where you desaturated the image, to correct your errors.
Here is my finished photo:
Isn't that cool?
Of course, we all know that there are lots of different ways to achieve selective colouring, but I can also see loads of other uses for this tool. Here's some ideas I have:
- Use your history brush to selectively recolour part of an image, as above, then use it again, with a much larger brush on a lower opacity to brush over the entire background so that all the colour shows through, but is softer than the focal image - you will end up with a colour photo with a subject that really POPS.
- Run a blur on the photo, then use the history brush to bring the focal subject back into it's original clear focus - you can make it look like you had an awesome lens when you shot the photo.
- Apply a filter to your photo, then use the history brush to bring parts of the photo back to the pre-filter state for a unique look.
- Add a texture and then use the brush to paint back areas you don't want the texture to show.
- .... ?