Effects

Spatial filters

Param	Type	Range	Description
blur	integer	1-250	Gaussian blur radius in pixels
sharpen	float	0-10	Unsharp mask amount

?blur=5         → subtle blur
?blur=50        → heavy blur (privacy, background)
?sharpen=2      → subtle sharpening

Blur uses a two-pass separable Gaussian in linear light (sRGB → linear → blur → sRGB) for physically correct results.

Color adjustments

Param	Type	Range	Description
brightness	integer	-100 to 100	Brightness adjustment
contrast	float	-100 to 100	Contrast adjustment
saturation	integer	-100 to 100	Saturation adjustment
grayscale	boolean	true	Convert to grayscale
sepia	boolean	true	Apply sepia tone

?brightness=20            → brighter
?contrast=15&saturation=10  → punchier colors
?grayscale=true           → black and white
?sepia=true               → vintage tone

Adjacent color adjustments are fused into a single pixel-iteration pass for performance.

Rotation & flip

Param	Type	Values	Description
rot	integer	90, 180, 270	Clockwise rotation
flip	enum	h, v	Horizontal or vertical flip

?rot=90        → rotate 90° clockwise
?rot=180       → upside down
?flip=h        → mirror horizontally
?flip=v        → mirror vertically

Rounded corners

Param	Type	Values	Description
r	integer or "max"	1-9999 or "max"	Corner radius in pixels

?r=20          → 20px rounded corners
?r=max         → fully circular (pill/avatar shape)

Use r=max with a square crop for perfect circular avatars:

?w=200&h=200&fit=cover&g=face&r=max