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Image distortion

A distortion changes where each output pixel reads its source. It transforms spatial relationships rather than directly changing the sampled color values.

Follow an output pixel back to its source coordinate

Where the output readssource coordinates
Source with inverse coordinate grid
Choose an output pixelclick · arrow keys
Output → source(24, 10) → (27.50, 10)
After horizontal wrap(27.50, 10)
xₛ = x + 7 sin(2πy / 24)Every output cell asks the source for a value. Fractional requests need interpolation. The source grid shows those requests; the source image itself stays fixed.

Sweep positive and negative wave amplitude while a fixed destination pixel traces its source coordinate. Use any control to take over.

What to try
  1. Choose an output pixel and change wave amplitude or wavelength.
  2. Compare nearest and bilinear sampling; set amplitude to zero to restore the source.
Open in the Lab ↗

What to look for: Inverse mapping asks the fixed source for each output value. The highlighted source coordinate can be fractional and wraps horizontally at the boundary.

How it works

Inverse mapping begins with an output location and asks which input coordinate belongs there. Offset shifts coordinates; waves add periodic displacements; twirl rotates more strongly near a center. Polar mapping exchanges angular/radial and rectangular coordinates. Kaleidoscope folds the image into repeated angular sectors.

The source coordinate is often fractional. Nearest sampling selects one pixel and bilinear sampling combines neighbors. The Lab’s bilinear interpolation uses premultiplied alpha. Boundary modes decide what happens when the requested coordinate lies outside the source.

Use it in the Lab

Use a dedicated distortion on the active layer and compare before committing. Keep document Rotate/Resize for global geometry and use these maps when the deformation itself is the image treatment.

Offset / wrap ↗Wave distortion ↗Twirl ↗Polar coordinates ↗Kaleidoscope ↗

Limits & distinctions

Remapping does not guarantee a seamless or reversible transformation. Folds, cropping and resampling can discard information, so preserve the source layer.

Sources & references

Guide updated