2D Inverse Fourier Transform Playground

Original image The input image (grayscale).	Spectrum Forward Fourier transform of the original image. Values are complex numbers; absolute values are shown for visualization.	Masked spectrum (edit here!) Left-drag / 1-finger: Erase mask Right-drag / 2-finger: Restore mask Wheel / Slider: Change brush size Brush size:	Result The result of inverse Fourier transform of the masked spectrum.

Image URL: or File:	Mask URL: or File:	Mask	Basis function The 2D sinusoidal wave at the cursor frequency.

Original image

The input image (grayscale).

Forward Fourier transform of the original image. Values are complex numbers; absolute values are shown for visualization.

Brush size:

The result of inverse Fourier transform of the masked spectrum.

Image URL:
or File:

Mask URL:
or File:

The 2D sinusoidal wave at the cursor frequency.

This is an interactive demo tool for understanding how 2D image Fourier transform works.

This work is inspired by Prof. Ohzawa's lecture. →video

Edit the mask on the Masked spectrum or Mask canvas:
- Erase mask: Mouse left-drag / 1-finger drag
- Restore mask: Mouse right-drag / 2-finger drag
- Change brush size: Mouse wheel / brush size slider
Change the input image by clicking a thumbnail or loading a file / URL.
Change the mask by clicking a thumbnail or loading a file / URL.

Source code (GitHub) — Any suggestions and issues are welcome.