Set Wavelet Decompose to Six Scales in GIMP

This guide explains how to properly configure GIMP's Wavelet Decompose tool to separate an image into six distinct frequency layers. By adjusting the Scales slider, you can break down an image into specific frequency bands, ranging from fine surface textures to broad tonal shifts, enabling advanced frequency separation for retouching.

Step-by-Step Configuration

  1. Select the Layer: Open your image in GIMP and ensure the layer you want to process is selected in the Layers panel.
  2. Open the Tool: Navigate to the top menu and select Filters > Enhance > Wavelet Decompose....
  3. Set the Scales Slider: In the dialog window that appears, locate the Scales slider. Set the value directly to 6 by either dragging the slider or typing 6 into the numerical input box.
  4. Configure Output Options:
    • Check Create a layer group if you want the generated layers neatly organized inside a single folder.
    • Leave the blending options at their defaults to ensure the decomposed layers visually reconstruct the original image perfectly.
  5. Apply the Filter: Click OK to execute the decomposition.

Understanding the Resulting Layers

Setting the slider to 6 instructs the algorithm to create six distinct detail layers along with one base layer:

  • Scale 1 to Scale 6 (Frequency Layers): GIMP creates six separate detail layers. Scale 1 contains the highest frequency details (such as fine pores, noise, and sharp edges). As you move up to Scale 6, the layers capture progressively lower frequency details (such as larger blemishes, soft shadows, and broader contours). Each of these layers uses the Grain merge blend mode.
  • Wavelet Residual: Below the six detail layers, GIMP places the residual layer. This layer contains the lowest frequencies, consisting entirely of the underlying base colors and broad tonal transitions without fine texture.

(Note: If your project specifically requires six layers in total including the residual base, set the Scales slider to 5, which yields five frequency layers plus one residual layer.)