optimize images

[janbeering]

• [x] find better methods for rgb scaling
• [ ] find use of alpha
• [x] probably image sharpener?
• [x] also look outside of python images

[janbeering]

• https://note.nkmk.me/en/python-opencv-bgr-rgb-cvtcolor/
• https://note.nkmk.me/en/python-opencv-numpy-alpha-blend-mask/
• https://www.tutorialspoint.com/how-to-change-the-contrast-and-brightness-of-an-image-using-opencv-in-python
• https://towardsdatascience.com/comprehensive-guide-to-satellite-imagery-analysis-using-python-1b4153bad2a
• https://www.planet.com/pulse/color-correction/
• https://tilemill-project.github.io/tilemill/docs/guides/landsat-8-imagery/