The Layers command returns the number of layers of an image. A grayscale image has one layer. A color image has three layers. A color image with alpha channel has four layers.

The img parameter is the image.

$\mathrm{with}\left(\mathrm{ImageTools}\right)\:$

$\mathrm{img}≔\mathrm{Create}\left(100\,200\,\mathrm{channels}=3\right)\:$

$\mathrm{Layers}\left(\mathrm{img}\right)$

$3$

$\mathrm{map2}\left(\mathrm{Layers}\,\mathrm{img}\,\left[\mathrm{size}\,\mathrm{lower}\,\mathrm{upper}\,\mathrm{range}\right]\right)$

$\left[3\,1\,3\,1..3\right]$

$\mathrm{img}≔\mathrm{Create}\left(100\,200\right)\:$

$\mathrm{Layers}\left(\mathrm{img}\right)$

$1$