# Binning

(bin_from)=
(bin_to)=

To reduce the time taken for GLCM, we shrink GLCM size by limiting the maximum value of the input.

```{note}

E.g. an image of max value 255 requires {math}`256\times 256` sized GLCM. Binning it to 15 will drastically
reduce to {math}`16\times 16`.

The arguments used are ``bin_from=256`` and ``bin_to=16``.
```

```pycon
>>> from glcm_cupy import GLCM
>>> import numpy as np
>>> from PIL import Image
>>> ar = np.asarray(Image.open("image.jpg"))
>>> g = GLCM(..., bin_from=256, bin_to=16).run(ar)
```

```{warning}
As we include 0, if an image's max value is 255, use ``bin_from=256`` .
```

## Time Scale

The time complexity is {math}`O(n^2)`

E.g. ``bin_to==a`` -> ``bin_to==a * 2``, the time needed scales by 4

## Recommendations

Try ``bin_to<=16`` for testing purposes, then increase when ready to use higher bins.

```pycon
>>> from glcm_cupy import GLCM, Direction
>>> g = GLCM(bin_from=256, bin_to=16)
```