3. HSV color scheme

Last chapter we discussed about how to do the histogram matching and did a lot of examples using different reference images. However, all of them are just gray-scale image. In this chapter, we would like to discuss how are we supposed to take advantage of those outputs and give the color back to the image.

Traditional RGB color scheme system is good for analyzing the image normally but this is not very useful in this situation. What we want to do is to analysis the image through HSV color scheme.

image1.1) Image for showing HSV color scheme

As we can see, in HSV color system, H(Hue) and S(Saturation) are the main factors deciding what is the pixel color, and V(Value) is the one which decides how bright it is. Since what we wanted for the image histograms are mostly for manipulating the light source, taking the value from the output of histogram matching will be the best option for us.

Therefore, we would like to keep H and S the same as the source image, and take the value only from the reference image (the output image after doing histogram matching).

So, here is the whole process so far:

1) Select a science-fiction style image

image2.1) science-fiction style image for reference

2) Select the source image

image2.2) source image

3) Image histogram matching

image2.3) output after histogram matching

4) Take the value of output image(image2.3) and take the hue and saturation of the source image(image2.2)

image2.4) final result in this chapter

Here is the different result from the reference image that we had in last chapter:

image3.1

image3.2

image3.3

image3.4

image3.5

image3.6

image3.7

image3.8

image3.9

image3.10

So here we can see tons of example where the brightness of an image was being modified using the reference image. However, we still have multiple examples of them and again, we should find a way to figure out which reference image to be used and that will be discussed in a later chapter.

Image credit:

https://en.wikipedia.org/wiki/HSL_and_HSV

https://visualcocaine.org/photo/1826/fantasy-planet-archer-woman-moon

http://www.diazmag.com/explorers-court-metrage/

https://www.mapmaker-malique.de/blog/gebaerende-kinder-und-gesellschaft/

https://www.wallpaperup.com/1081091/naves_futuristas_sci-fi_aliens.html

http://blogs.adobe.com/creative/visual-trends-rueckblick-2017/

https://pixabay.com/images/search/science%20fiction/

https://www.this-is-cool.co.uk/the-sci-fi-concept-art-of-adam-kuczek/

https://www.freelancer.com/contest/Scifi-Human-vague-concept-art-1055269-byentry-15178777

http://hdqwalls.com/scifi-concept-art-fantasy-wallpaper

https://www.msn.com/nl-be/entertainment/film/netflix-koopt-rechten-op-chinese-megahit-the-wandering-earth/ar-BBTVEFP