In the previous blog, I reviewed 1D-DCT and 2D-DCT. In this blog, I will check what would happen if you denoise the image via 1D-DCT on flattened image.

# Denoising¶

I will denoise the image by first transforming an image to frequency domain and pick the top $k$ largest DCT coefficients in absolute values. The remaining DCT coefficients are sparcified to zero. The new DCT coefficients are then inverse DCTed to spacial domain. The recovered image is visualized.