ui.Chart.image.histogram

  • Generates a chart displaying the frequency distribution of pixel values within a specified image region.

  • The chart plots histograms for each band of the image, showing the number of pixels with values falling within specific ranges (buckets).

  • Users can customize the chart by defining the region, scale, and bucket parameters, as well as the maximum number of input values and pixels used in the calculation.

  • The chart is rendered with customizable axes, titles, and color options for each band.

  • ui.Chart.image.histogram() returns a ui.Chart object, allowing for further manipulation and display within the Earth Engine Code Editor.

Generates a Chart from an image. Computes and plots histograms of the values of the bands in the specified region of the image.

  - X-axis: Histogram buckets (of band value).

  - Y-axis: Frequency (number of pixels with a band value in the bucket).

Returns a chart.

UsageReturns
ui.Chart.image.histogram(image, region, scale, maxBuckets, minBucketWidth, maxRaw, maxPixels)ui.Chart
ArgumentTypeDetails
imageImageThe image to generate a histogram from.
regionFeature|FeatureCollection|Geometry, optionalThe region to reduce. If omitted, uses the entire image.
scaleNumber, optionalThe pixel scale used when applying the histogram reducer, in meters.
maxBucketsNumber, optionalThe maximum number of buckets to use when building a histogram; will be rounded up to a power of 2.
minBucketWidthNumber, optionalThe minimum histogram bucket width, or null to allow any power of 2.
maxRawNumber, optionalThe number of values to accumulate before building the initial histogram.
maxPixelsNumber, optionalIf specified, overrides the maximum number of pixels allowed in the histogram reduction. Defaults to 1e6.

Examples

Code Editor (JavaScript)

// Define a MODIS surface reflectance composite.
var modisSr = ee.ImageCollection('MODIS/006/MOD09A1')
                  .filter(ee.Filter.date('2018-06-01', '2018-09-01'))
                  .select(['sur_refl_b01', 'sur_refl_b02', 'sur_refl_b06'])
                  .mean();

// Define a region to calculate histogram for.
var histRegion = ee.Geometry.Rectangle([-112.60, 40.60, -111.18, 41.22]);

// Define the chart and print it to the console.
var chart =
    ui.Chart.image.histogram({image: modisSr, region: histRegion, scale: 500})
        .setSeriesNames(['Red', 'NIR', 'SWIR'])
        .setOptions({
          title: 'MODIS SR Reflectance Histogram',
          hAxis: {
            title: 'Reflectance (scaled by 1e4)',
            titleTextStyle: {italic: false, bold: true},
          },
          vAxis:
              {title: 'Count', titleTextStyle: {italic: false, bold: true}},
          colors: ['cf513e', '1d6b99', 'f0af07']
        });
print(chart);