Color：Logarithmic and Line
Colorcorrect(pressing C on Node Graph)
The ColorCorrect node is used to make quick adjustments to contrast, gamma, gain, and offset. You can apply these to a clip’s master (entire tonal range), shadows, midtones, or highlights.
You can control the range of the image that is considered to be in the shadows, midtones, and highlights using the lookup curves on the Ranges tab. However, do not adjust the midtone curve – midtones are always equal to 1 minus the other two curves.
OCIOColorSpace
Much like the standard ColorSpace node, you can use the OCIOColorSpace node for converting an image sequence from one colorspace to another. The OCIOColorSpace node is based on the OpenColorIO library.
Blur:
Erode blur
Similar to Erode (filter) , but smoother, input pixels are filtered relative to the size control. Negative values cause brighter areas to expand into darker areas and positive values cause darker areas to expand into lighter areas – particularly useful with mattes. Additionally, you can add blur to the input using the blur and quality controls.