[Basic tutorial] How to blank out areas from a picture

[jana]

kake has asked for a basic tutorial explaining how you can blank out areas from a picture (e.g., with rectangle select and bucket fill). Let me know if anything's unclear in this tutorial, or in case I missed something. Click on images for full size.

I had huge trouble uploading the images earlier, but luckily t_fischer has helped me out...

1. Open Image

2. Save as GIMP file.

Go to File > Save As OR press Ctrl+Shift+S. Save image as "pick-an-image-name.xcf" This file format allows you to work on an image without deleting/overwriting the original image.

3. Add a layer to your image.

An additional layer allows you to make changes to an image without working directly on it.

What you need in this case is a "Transparent" layer so that you can still see the image below. Give the layer a proper name.

To view all your layers, go to Windows > Dockable Dialogues > Layers OR press Ctrl+L.

4. Create rectangle (to hide part of the image).

Click on the rectangle in the tool box, then click on the image and draw the rectangle where you like it.

It should now look like in the image above. The "marching ants" effect tells you that this part of the picture is selected. Don't click anywhere else on the image now, otherwise the rectangle will disappear and you'll have to try again.

Make sure your transparent layer is activated (press Ctrl+L to view all layers).

5. Fill rectangle with a FG/BG color

Click on the bucket in the tool box.

If you want to use a specific FG/BG color, click on the two color fields, otherwise just fill your rectangle with the displayed FG color by clicking with the bucket/mouse in the selected area.

We want to change the FG/BG color to some green color. Click OK to choose the green color of your choice.

Click on the selected rectangle and fill it with the preferred green color.

6. Save image as png file

Go to File > Save As OR press Ctrl+Shift+S.

Since you have two visible layers, GIMP tells you that you have to merge them if you want to save your image as a png-file. Choose "Merge visible layers" and click on "Export".

Here you can change some of the image's properties, but I suggest you leave it as it is (that's probably a topic for another tutorial...) and click on "Save".

7. Done.