Krita
Pixel-based image manipulation program
Krita is the full-featured digital art studio.
It is perfect for sketching and painting, and presents an end–to–end solution for creating digital painting files from scratch by masters.
Krita is a great choice for creating concept art, comics, textures for rendering and matte paintings. Krita supportsmany colorspaces like RGB and CMYK at 8 and 16 bits integer channels, as well as 16 and 32 bits floating point channels.
Have fun painting with the advanced brush engines, amazing filters and many handy features that make Krita enormously productive.
Krita is a creative application for raster images. Whether you want to create from scratch or work with existing images, Krita is for you. You can work with photos or scanned images, or start with a blank slate. Krita supports most graphics tablets out of the box. . Krita is different from other graphics design programs in that it has pluggable brush engines, some supporting brush resources like Gimp brush files, others offering sophisticated simulation of real brushes, and others again offering color mixing and image deformations. Moreover, Krita has full support for graphics tablets, including such features as pressure, tilt and rate, making it a great choice for artists. There are easy to use tools for drawing lines, ellipses and rectangles, and the freehand tool is supported by pluggable "drawing assistants" that help you draw shapes that still have a freehand feeling to them.
How to install Krita in Ubuntu
If you are on a supported distro, you can install the application through software center by clicking the below link.
If the above link not working, run the below command in terminal to install krita in Ubuntu
sudo apt install krita
Krita Screenshots