Feature Description

Performs histogram statistics on a raster dataset. The returned result type is countJSON (String).

Histogram

A histogram, also known as a bar chart, represents the distribution of a dataset using a series of rectangles of varying heights. Typically, the horizontal axis represents categories, while the vertical axis represents the distribution.

In a raster histogram, the horizontal axis represents groups of raster values. The raster values are divided into N groups (default is 100), where each group corresponds to a range of raster values. The vertical axis represents frequency, which is the number of cells whose raster values fall within the range of each group.

The following figure is a schematic diagram of a raster histogram. The minimum and maximum values of the raster data are 0 and 100, respectively. Using 10 groups, the frequency for each group is calculated and plotted as the histogram below. The frequency for each group is labeled above its rectangle. For example, group 6 has a raster value range of [50,60). There are 3 cells in the raster data with values within this range, so the frequency for this group is 3. Note: The value range for the last group in the histogram is closed on both ends, while all other groups are closed at the lower bound and open at the upper bound.

The following figure shows an example of raster histogram statistics. In this example, the minimum raster value is 250, the maximum raster value is 1243, and the number of groups is 500. The frequency for each group is obtained from the returned histogram JSON object, and the raster histogram shown below is plotted. The raster histogram provides an intuitive understanding of the distribution of raster values in the raster dataset.

Parameter Description