Representative Color Transform for Image Enhancement

problem

• low contrast image!

previous works

• normally perform channel-wise intensity transform or some encoder-decoder architecture

proposed method

• representative color transform
  • run image through encoder
  • embedding vector $R$ is in $\mathbb{R}^{N \times C}$ where $C$ is the number of “representative color”s
  • compare with $\mathbb{R}^{N\times3}$ vector $T$ showing R, G, B values post-transform
  • get features $F$ from image via CNN
  • $A = softmax(FR^T/\tau)$, enhanced image $Y = AT^T$
• local RCT (the above would be the “global” version)
  • use fine-scale features covering a subset of the original image