How to Change Image Precision in GIMP

This guide explains how to switch image precision in GIMP between gamma-corrected integer formats and linear light floating-point representations. Adjusting image precision allows you to move between lightweight, display-ready formats and high-bit-depth workflows suited for advanced editing and compositing. Below, you will find direct instructions for modifying these settings along with an overview of when to use each mode.

Steps to Change Image Precision

  1. Open your project or image file in GIMP.
  2. Click on the Image menu in the top navigation bar.
  3. Hover over the Precision submenu to reveal the available depth and encoding options.
  4. Select your desired bit depth:
    • 8-bit integer, 16-bit integer, or 32-bit integer for fixed integer values.
    • 16-bit floating point or 32-bit floating point for high dynamic range editing.
  5. In the same Precision submenu, select the color encoding:
    • Select Linear light to process colors physically and eliminate artifacts during blending and blurring.
    • Select Non-linear (Perceptual gamma) for traditional gamma-corrected storage.

When downsampling precision (such as moving from 32-bit floating point to 8-bit integer), GIMP will display a dialog box asking you to choose dithering methods to reduce color banding. Choose your dithering preference and click Convert.

Understanding the Formats

  • Linear Light Floating-Point (32-bit or 16-bit): In linear mode, light values correspond directly to physical scene light without gamma curves applied. Floating-point precision prevents data clipping below 0.0 (pure black) and above 1.0 (pure white). Use this mode when performing heavy photo manipulation, blurs, color grading, or working with HDR photography.
  • Gamma-Corrected Integer (Typically 8-bit or 16-bit): Perceptual gamma encoding allocates more data to darker tones to match how human vision perceives light. Integer formats consume significantly less system memory and storage. Use this setting when preparing images for final web export, standard displays, or file formats like standard JPEG and 8-bit PNG.