# Adjustment

Perform operations similar to those in image-editing applications.

# Background &bg=

Sets the background color of the image. Supports a variety of color formats. In addition to the 140 color names supported by all modern browsers (listed here), it also accepts hexadecimal RGB and RBG alpha formats.

Valid hexadecimal formats:

  • 3 digit RGB: CCC
  • 4 digit ARGB (alpha): 5CCC
  • 6 digit RGB: CCCCCC
  • 8 digit ARGB (alpha): 55CCCCCC

More info: Issue #81 - Background setting.

<img src="//images.weserv.nl/?url=images.weserv.nl/transparency_demo.png&w=400&bg=black">


# Blur &blur=

Adds a blur effect to the image. Use values between 0 and 100.

More info: Issue #69 - Allow blur transformation (with radius parameter).

<img src="//images.weserv.nl/?url=images.weserv.nl/lichtenstein.jpg&w=300&blur=5">


# Contrast &con=

Adjusts the image contrast. Use values between -100 and +100, where 0 represents no change.

<img src="//images.weserv.nl/?url=images.weserv.nl/lichtenstein.jpg&w=300&con=25">


# Filter &filt=

Applies a filter effect to the image. Accepts greyscale, sepia, duotone or negate.


You can use &start and &stop to define the duotone colors. By default, it will use &start=C83658 and &stop=D8E74F.

<img src="//images.weserv.nl/?url=images.weserv.nl/zebra.jpg&w=300&h=300&fit=cover&a=focal-82-0&filt=duotone">


# Gamma &gam=

Adjusts the image gamma. Use values between 1 and 3. The default value is 2.2, a suitable approximation for sRGB images.

<img src="//images.weserv.nl/?url=images.weserv.nl/lichtenstein.jpg&w=300&gam=3">


# Modulate &mod=New!

Transforms the image using brightness, saturation and hue rotation. Use &mod=[brightness multiplier], [saturation multiplier],[hue degrees] to define the below adjustments at once.

# Brightness &mod=

Adjusts the brightness of the image. A multiplier greater than 1 will increase brightness, while a multiplier less than 1 will decrease the brightness.

<img src="//images.weserv.nl/?url=images.weserv.nl/lichtenstein.jpg&w=300&mod=2">


# Saturation &sat=

Adjusts the saturation of the image. A multiplier greater than 1 will increase saturation, while a multiplier less than 1 will decrease the saturation.

<img src="//images.weserv.nl/?url=images.weserv.nl/lichtenstein.jpg&w=300&sat=0.5">


# Hue rotation &hue=

Applies a hue rotation to the image. A positive hue rotation increases the hue value, while a negative rotation decreases the hue value.

Values are given in degrees, there is no minimum or maximum value; &hue=N evaluates to N modulo 360.

<img src="//images.weserv.nl/?url=images.weserv.nl/lichtenstein.jpg&w=300&hue=90">

Hue rotation

# Sharpen &sharp=

Sharpen the image. Performs an accurate sharpen of the L channel in the LAB color space. Use in combination with &sharpf= and &sharpj= to control the level of sharpening in "flat" and "jagged" areas.

<img src="//images.weserv.nl/?url=images.weserv.nl/lichtenstein.jpg&w=300&sharp=3">


# Tint &tint=New!

Tint the image using the provided chroma while preserving the image luminance. See here for the supported color formats.

<img src="//images.weserv.nl/?url=images.weserv.nl/lichtenstein.jpg&w=300&tint=red">