
The glare node can be used for adding extra bloom to highlights in an image, simulating atmospheric glow, or lens filters. The various filters work best on HDR image sources, isolating highlights with a threshold.
The bilateral blur node performs a high quality adaptive blur on the source image. It can be used for tasks such as smoothing results from Blender's raytraced ambient occlusion, smoothing results from noisy unbiased renderers, faking performance-heavy processes, like blurry refractions/reflections, soft shadows, or other non-photorealistic compositing effects
Lens distortion simulates optical effects such as barrel distortion, pincushion distortion and chromatic aberration, as exhibited by some camera lenses.

Tone mapping is the process of compressing the contrast of a high dynamic range image, in order for it to fit within the low dynamic range visible on current display devices. You can use this to bring overbright colors from renders back into range, as well as directly on HDR images. Blender's tonemap node provides two techniques that can provide different results depending on the input image source.

A node to convert between different types of alpha in images: premultiplied alpha which means the R, G and B values are multiplied by the alpha value, and 'key' alpha where the RGB channels are independent of the alpha channel.