libjpeg-turbo (required version >= 2.1.3), libjpeg-turbo is a JPEG image codec that uses SIMD instructions (MMX, SSE2, AVX2, Neon, AltiVec) to accelerate baseline JPEG compression and decompression on x86, x86-64, Arm, and PowerPC systems, as well as progressive JPEG compression on x86 ...
For the first image, which has some mountaineers climbing, I used vector layers in Krita to add basic shapes and then used Alpha Inheritance, which is similar to what is called Clipping Masks in Photoshop, to add texture and gradients inside the shapes. This helped me change the underlying ...