Images

Resizes an image’s width (while preserving original ratio) according to the queried preset and transforms it to the queried format, e.g. if you have the default settings and a path/to/image.png file inside /path/to/workdir/assets/img, you can use any of the following URL formats:

# Preset-based (using configured presets)
http://localhost:8080/img/lg/path/to/image.webp
http://localhost:8080/img/lg2x/path/to/image.png
http://localhost:8080/img/sm/path/to/image.jpg
http://localhost:8080/img/sm2x/path/to/image.avif

# Direct width (height auto-calculated to preserve aspect ratio)
http://localhost:8080/img/640/path/to/image.jpg
http://localhost:8080/img/1920/path/to/image.png

# Direct width x height (with fit parameter)
http://localhost:8080/img/640x480/path/to/image.jpg
http://localhost:8080/img/800x600/path/to/image.png?fit=cover

Basic resizing uses vips when available, with ImageMagick as a fallback. Rotation, flipping, crop positioning, brightness, contrast, gamma and filters use ImageMagick. Install ImageMagick to use these transformations. Image processing commands stop when their request context is canceled.

Transformation options

• fit=contain (default): Image is resized to fit within the dimensions while preserving aspect ratio
• fit=cover: Image is resized to cover the entire dimensions, cropping excess (center-aligned)
• rotate: Rotation in degrees (0, 90, 180, 270)
• flip: Flip image (horizontal, vertical, both)
• crop: Crop position for fit=cover with both width and height (top-left, top, top-right, left, center, right, bottom-left, bottom, bottom-right)
• brightness: Brightness adjustment (-100 to 100)
• contrast: Contrast adjustment (-100 to 100)
• gamma: Gamma adjustment (0.1 to 10.0)
• filter: Apply filter (comma-separated: ?filter=grayscale,blur)
  • grayscale: Convert to grayscale
  • sepia: Apply sepia tone
  • blur: Apply blur
  • sharpen: Sharpen image
  • negate, invert: Invert colors
  • normalize: Normalize image levels
  • equalize: Histogram equalization
  • contrast: Increase contrast
  • edge: Detect edges
  • emboss: Emboss effect
  • charcoal: Charcoal drawing effect
  • solarize: Solarize effect
  • paint: Oil painting effect
  • oil: Oil painting effect (stronger)
  • sketch: Sketch effect
  • vignette: Vignette effect

Image results are cached. When upgrading from an older version or changing a preset, clear the affected image cache to regenerate existing results; -clear-gob clears only the configuration cache.