Using an algorithm to color black and white pictures of Lebanon.

May 17, 2016

Let there be color! is an amazing project by students from Waseda University.
Here is the official title of the project: Joint End-to-end Learning of Global and Local Image Priors for Automatic Image Colorization with Simultaneous Classification
It does sound like vodoo to me and it looks a bit intimidating. Here is the diagram that explains their algorithm:

They provide the code and instructions on github. I spent some time tinkering around and colouring old historical pictures in DC/Beirut and from the Library of Congress archive. I tried different types of images to see how good the alogrithm fares and it was pretty impressive. Here are some of the coloured pictures in Beirut.

I started with an outdoor city picture:

I moved to a picture with more greenery.

I decided to go for a more generic picture, I chose this one because I could guess some of the colors (Coca Cola logo is in red, this would be a test of the R in RGB)

I wanted to test green and blue in the same image. ( the GB of RGB)

Then I remembered, we have cedars and old forests, so i started digging around for old “green” picutres of Lebanon

What is impressive about the next picture, is that the algorithm got the coloring so right for the details in the picture. (except for a small part of the water)

I love the shading of the soil with the different shades of brown.

The alogrithm works well on rocks, and I liked how some parts of rocks are darker.

If you show that picture to me, I wouldn’t guess it was convereted from black and white

This next set of picture was more tricky, because the images had some sepia effect added to them.

I looked up old pictures of Batroun, I could mostly find pictures of Msailha Castle, the coloured version looks surprisingly like present day.

So, a big cheers to the authors of this algorithm Satoshi Iizuka, Edgar Simo-Serra and Hiroshi Ishikawa. This is truly some good science. I had a lot of fun converting images, and I couldn’t help myself get excited everytime a new image got its colours back.

@Article{IizukaSIGGRAPH2016, author = {Satoshi Iizuka and Edgar Simo-Serra and Hiroshi Ishikawa}, title = , journal = “ACM Transactions on Graphics (Proc. of SIGGRAPH 2016)”, year = 2016, volume = 35, number = 4, }