# Infragram Sandbox

« Back to Infragram

The Infragram Sandbox is a browser based tool for experimenting with image compositing, intended for use with Public Lab Infragram cameras.

Read this research note and watch this short video to get a quick idea of how to use it:

## Infragrammar

Infragram Sandbox uses simple math expressions, which are actually written in JavaScript. Here are some examples:

• NDVI = (R-B)/(R+B) for -1..1, or for 0..1 (((R-B)/(R+B))+1)/2 in the Monochrome input
• ENDVI = ((R+G)-(2*B))/((R+G)+(2*B)) which MaxMax uses for its vegetation stress cameras, in the Monochrome input
• A colormapped NDVI, scaled to emphasize differentiation: ((R-B)/(R+B)-0.2)*-720, in the Hue input, and tweaking the 0.2 value to between 0.1 and 0.9 (read more here)

### Math

Infragrammar can use JavaScript math functions. These include:

• Math.log() - logarithms
• Math.abs() - absolute value
• Math.sin() - sine

### Sliders

You can also link an equation to a slider; for now we are using the letter "X" to represent this value, but in the future, any string represented as {mystring} will generate a slider called "mystring". Move the slider to try different values in real time.

near-infrared-camera ndvi infrared infragram infragram-sandbox

parent:infragram