Clean using the clone tool

Here is a picture I took of a dog on a beach:

 Fig. 1 Original image.

I like the picture. The only problem is that it has spots. Some of these are marked with red circles in the image below.

 Fig. 2 Original image with some of the spots marked in red circles.

These were caused due to dust on the lens and sensor of my DSLR. I freely change lenses on my DSLR not caring much that dust might enter the camera body, so this is expected. I did clean my lens and the camera later on, but what about this image. Well, one way to clean it up in post-processing is by using the "clone"  tool. The cleaned-up image is shown below. The clean-up is not complete, but you get the idea.
 

Fig. 3 Cleaned up image after using the "clone" tool.

Another example is shown below. The picture on the left is the original picture and has a lot of spots. The cleaned up image (after using the clone tool is shown on the right). I think I even adjusted the "levels" because of which there is a slight difference in color. But you do get the idea of the clean-up.

Fig. 4 The original (on the left) and the cleaned-up (on the right) images.

So this is one of the situations where you can made good use of the cloning tool. How to use the tool ? You can find a lot of tutorials on the internet. Or simply check the help section of your image editing software. Or let me know and I might write about it sometime later.