LAS format - RGB and intensity values

[Keven Corazza]

Hello everybody,

we are developing a desktop solution and we are including LAS/LAZ format by using a .NET library called laszip.net.dll. We are having a problem, with intensity and with RGB values.

 

We have some LAS file with intensity between 0 and 255, and other LAS files with intensity around 20000. The same happens for RGB. 

We don’t know which is the intensity and RGB range of values in order to convert in our format.

Someone help can help us ?

Thank you in advance.

Keven Corazza

LSE

[Edgar Veldman]

Hi Keven,

Intensity and RGB can be stored as an 8 bit or 16 bit value.

Intensity 8 bit will give you 256 shades of gray, RGB 8 Bit 256 shades of either red, green and blue. This is most likely the case with your data, you are looking at either 8 bit or 16 bit colour ranges.

When the RGB or intensity of your data is collected (or stored) as a 16 bit value, you have much wider range of colours available, 65536 shades of gray, red, green, or blue.

You can always resample the data back to 8 bits (or up to 16 bits) if you want to make your datasets based on the same colour ranges.

You can do this with any lastool, using these syntaxes: -scale_rgb_up, -scale_rgb_down, or for intensity use the  -scale_intensity 256 to scale up from 8bit to 16bit, etc.

Edgar