# filters.colorinterp

The color interpolation filter assigns scaled RGB values from an image based on a given dimension. It provides three possible approaches:

1. You provide a `minimum` and `maximum`, and the data are scaled for the given `dimension` accordingly.
2. You provide a `k` and a `mad` setting, and the scaling is set based on Median Absolute Deviation.
3. You provide a `k` setting and the scaling is set based on the `k`-number of standard deviations from the median.

You can provide your own GDAL-readable image for the scale color factors, but a number of pre-defined ramps are embedded in PDAL. The default ramps provided by PDAL are 256x1 RGB images, and might be a good starting point for creating your own scale factors. See Default Ramps for more information.

Note

filters.colorinterp will use the entire band to scale the colors.

Default Embedded Stage

This stage is enabled by default

## Example

    {
      "pipeline":[
        "uncolored.las",
        {
          "type":"filters.colorinterp",
          "ramp":"pestel_shades",
          "mad":true,
          "k":1.8,
          "dimension":"Z"
        },
        "colorized.las"
      ]
    }

Image data with interpolated colors based on `Z` dimension and `pestel_shades` ramp.

## Default Ramps

PDAL provides a number of default color ramps you can use in addition to providing your own. Give the ramp name as the `ramp` option to the filter and it will be used. Otherwise, provide a GDAL-readable raster filename.

### `awesome_green`

### `black_orange`

### `blue_orange`

### `blue_hue`

### `blue_orange`

### `blue_red`

### `heat_map`

### `pestel_shades`

## Options

ramp
  The raster file to use for the color ramp. Any format supported by GDAL may be read. Alternatively, one of the default color ramp names can be used. [Default: `pestel_shades`]
dimension
  A dimension name to use for the values to interpolate colors. [Default: `Z`]
minimum
  The minimum value to use to scale the data. If none is specified, one is computed from the data. If one is specified but a `k` value is also provided, the `k` value will be used.
maximum
  The maximum value to use to scale the data. If none is specified, one is computed from the data. If one is specified but a `k` value is also provided, the `k` value will be used.
invert
  Invert the direction of the ramp? [Default: false]
k
  Color based on the given number of standard deviations from the median. If set, `minimum` and `maximum` will be computed from the median and setting them will have no effect.
mad
  If true, `minimum` and `maximum` will be computed by the median absolute deviation. See filters.mad for discussion. [Default: false]
mad_multiplier
  MAD threshold multiplier. Used in conjunction with `k` to threshold the diferencing. [Default: 1.4862]