Can I write a paper on a method that is novel but yields similar results compared to existing methods? I have developed a method that gives similar results (in few cases: better) compared to existing methods and I want to publish it. Can I do this and if yes, how do I motivate it? More specifically:

I am a undergraduate researcher, investigating methods to detect X in images. We have a solution using two images and another method proposed in the literature before also used two images.

Recently we discovered that we can solve the same problem in a very different manner if we use three images (taken differently) and still get similar results. This technique will be based on a particular observation and it is not discussed in the literature. Does it make a good paper given that the problem can be solved using two images with similar results?

How should I write and explain it in my paper about why I am using three images instead of two, because the results obtained are similar? The way in which the three images are taken is different from taking two images and our observation in the three-image-case seems to be novel.

Edit (from comment): In some cases our previously proposed method which uses 2 images gives inaccurate results compared to 3 image solution.
As your three-image method takes a new approach, it is novel in the academic sense: It adds to the existing knowledge. Thus you should be able to publish a paper on this, though probably not in a high-ranking journal (unless you blatantly underestimated the advantages of your method). The rationale for this is the following and you may use it to motivate your method in your paper: Your new approaches may inspire other methods which in turn may drastically outperform existing ones or yield entirely new information.

You could write the paper directly in this tone, not focussing on the method you are presenting but on the fact that you can extract the information your method (and the others) yield in a new way. In this context, you may consider not presenting your method primarily as a method, but as a way to verify your approach to extract the existing information.

You might get bonus points, if you actually have suggestions how to improve your method to outperform the existing ones.