GIMP Skin Retouching with Wavelet Decompose

This guide explains how to achieve professional, non-destructive skin retouching in GIMP using the Wavelet Decompose filter. By splitting your portrait into distinct layers of texture and color, you can remove acne, scars, and blemishes on high-frequency layers while simultaneously smoothing uneven skin tones on low-frequency layers, guaranteeing that natural pore structure remains crisp and sharp rather than artificially blurred.

Step 1: Apply Wavelet Decompose

  1. Open your portrait in GIMP and duplicate the base image layer (Ctrl + Shift + D or Cmd + Shift + D) to preserve an original backup.
  2. Select the duplicated layer and navigate to Filters > Enhance > Wavelet Decompose.
  3. Set the Scales slider between 5 and 7 (5 or 6 works best for standard portraits; higher resolutions may require 7).
  4. Ensure Create a layer group is checked.
  5. Click OK. GIMP will generate a folder containing a series of grey "Scale" layers (fine-to-coarse details) and a single "Residual" layer at the bottom (broad color and tone).

Step 2: Identify Your Texture Layers

  • Scales 1 and 2 (High Frequency): Contain micro-textures such as fine pores, individual hairs, small flakes, and tiny pimples.
  • Scales 3 to 5 (Medium Frequency): Contain larger bumps, deep wrinkles, and localized shadows.
  • Residual (Low Frequency): Contains all the base color, redness, highlights, and broad skin tones with no sharp detail.

Step 3: Remove Blemishes on High-Frequency Layers

To remove pimples, ingrown hairs, and surface flaws without blurring:

  1. Select Scale 1 or Scale 2 in the Layers panel (identify which layer contains the visible defect by toggling layer visibility).
  2. Select the Healing Tool (H) or the Clone Tool (C).
  3. In the Tool Options, set the Source to Image and ensure Sample merged is unchecked. The tool must only sample the active grey layer.
  4. Set brush hardness to around 50–75% so texture borders blend naturally.
  5. Hold Ctrl (or Cmd) and click an adjacent, clean patch of skin on the active grey layer to set your sample point.
  6. Paint over the blemish. The tool copies clean pore texture over the flaw without altering underlying skin tones or creating soft, blurry artifacts.

Step 4: Smooth Skin Tone on the Low-Frequency Layer

To eliminate blotchiness, redness, or dark circles without touching the pores:

  1. Select the Residual layer at the bottom of the wavelet group.
  2. Select the Healing Tool or a soft Paintbrush/Airbrush set to a low opacity (15–25%).
  3. With Sample merged unchecked, sample an area with smooth, ideal skin tone.
  4. Gently paint over blotchy patches, redness around the nose, or uneven shadows under the eyes.
  5. Alternatively, use the Free Select Tool (F) with a feathered edge to outline an uneven color region on the Residual layer, then apply Filters > Blur > Gaussian Blur with a low radius (5–15 px). Because the high-frequency scales sit above the Residual layer in the stack, this blur only affects color transitions, leaving pore definition completely sharp.

Step 5: Final Review

  1. Zoom out to 100% to evaluate the result in context.
  2. If any area looks overly edited, select the specific Scale layer and lower its layer opacity slightly to reintroduce a controlled amount of original variation.
  3. Once satisfied, right-click the Wavelet Decompose layer group and select Merge Layer Group or New from Visible to complete the edit.