BUILT-IN MATHEMATICA SYMBOL

# ImageLevels

ImageLevels[image]
gives a list of pixel values and counts for each channel in image.

ImageLevels[image, n]
bins pixel values into n equally spaced levels.

ImageLevels[image, n, {min, max}]
puts all values into n bins between min and max.

## Details and OptionsDetails and Options

• ImageLevels gives a list of results for each channel. The result for each channel is a list of pairs, each giving the minimum value and count for a particular pixel value bin.
• ImageLevels[image] is equivalent to ImageLevels[image, 256].
• For binary images, ImageLevels[image] gives a result of the form .
• ImageLevels[image, n] by default takes the first bin to start at and the last one to end at . Channel values below or above are placed in the first and last bins, respectively.
• ImageLevels[image, n, {min, max}] takes the first bin to start at min, and the last bin to end at max.
• ImageLevels[image, n, All] gives n equally spaced bins, extending over the complete range of values in each channel.
• In ImageLevels[image, n, {min, max}], either min or max individually can be All.
• ImageLevels[image, "Byte"] gives the levels of image scaled to the range 0 to 255.
• ImageLevels[image, All] returns a tally of all pixel values occurring in image.
• ImageLevels puts pixels with values below the first bin into the first bin, and pixels with values above the last bin into the last bin. With an option setting "Clipping"->False, pixels with values outside the range of bins are not counted.
• ImageLevels works with Image3D objects.

## ExamplesExamplesopen allclose all

### Basic Examples (2)Basic Examples (2)

Count the number of pixels in each of 10 intensity levels:

 Out[1]=

Levels of a three-channel image:

 Out[1]=