grayslice (Image Processing Toolbox)

Image Processing Toolbox

grayslice

Create indexed image from intensity image using multilevel thresholding

Syntax

```
X = grayslice(I,n)
X = grayslice(I,v)
```

Description

X = grayslice(I,n) thresholds the intensity image I using cutoff values

, returning an indexed image in X.

X = grayslice(I,v), where v is a vector of values between 0 and 1, thresholds I using the values of v, returning an indexed image in X.

You can view the thresholded image using imshow(X,map) with a colormap of appropriate length.

Class Support

The input image, I, can be of class uint8, uint16, or double. Note that the threshold values are always between 0 and 1, even if I is of class uint8 or uint16. In this case, each threshold value is multiplied by 255 or 65535 to determine the actual threshold to use.

The class of the output image, X, depends on the number of threshold values, as specified by n or length(v). If the number of threshold values is less than 256, then X is of class uint8, and the values in X range from 0 to n or length(v). If the number of threshold values is 256 or greater, X is of class double, and the values in X range from 1 to n+1 or length(v)+1.

Example

I = imread('ngc4024m.tif');
X = grayslice(I,16);
imshow(I)
figure, imshow(X,jet(16))

See Also

gray2ind

gray2ind graythresh