语法
  BW = im2bw(I,level)
  BW = im2bw(X,cmap,level)
  BW = im2bw(RGB,level)

说明
BW = im2bw(I,level) 将灰度图像I转换为二进制图像BW, I中大于level的替换为1，否则替换为0.
BW = im2bw(X,cmap,level) 通过颜色空间表将X转换为二进制图像.
BW = im2bw(RGB,level) 将RGB值转换为二进制图像.

示例

data = [0.1 0.2 0.3 0.4 0.5 0.6]
data1= im2bw(data, 0.3)

data =
0.100000000000000 0.200000000000000 0.300000000000000 0.400000000000000 0.500000000000000 0.600000000000000
data1 =
0 0 0 1 1 1