Image types determine the way the computer interprets data matrix elements as pixel intensity values.  SciLab has the special capability of converting between image types for necessary purposes.

Images can be imported to SciLab and converted to different representations simply using SIVP module

//Making use of SIVP - Scilab Image and Video Processing Toolbox
I = imread('lena.png');
J = rgb2gray(I);
K = im2bw(I, 0.3);  // 0.3 being the threshold
imshow(J);

The below figures shows the Original color image, and its grayscale and  binary versions

1. Original Color Image

2. Gray scale Image