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ImageLevels

Status: Stable

documented, exercised by the test suite and/or worked examples, with no known limitations recorded.

Description

ImageLevels[image] gives {{level, count}, ...}: the histogram as DATA, not a plot -- use Histogram over the result for a picture. ImageLevels[image, n] uses n bins. Levels are on the same unit scale as ImageData, so a level can be compared against a pixel value without rescaling. A "Bit" image uses its 2 natural levels and "Byte" its 256, because those ARE the distinct values; a "Real" image has no natural set and is binned into 256 over [0, 1]. The counts sum to the pixel count exactly, every pixel landing in one bin. Accepts volumes as well as planes.

Examples (3)

Every input below was run against the current Mathilda build and its output recorded.

Basic Examples (2)

In[1]:= bit = Image[Table[Boole[Mod[i + j, 2] == 0], {i, 1, 8}, {j, 1, 8}]];

In[2]:= ImageLevels[bit]
Out[2]= {{0.0, 32}, {1.0, 32}}

Scope (1)

In[3]:= ImageLevels[Image[{{0, 1}, {1, 0}}]]
Out[3]= {{0.0, 2}, {1.0, 2}}

Implementation notes

Attributes: Protected.

References

See also: Histogram, ImageData