Next: 2.3 Boolean Up: 2. VIPS packages Previous: 2.1 Arithmetic Contents

# 2.2 Relational

See figure 2.2.

Relational functions compare images to other images or to constants. They accept any image or pair of images (provided they are the same size and have the same number of bands -- their types may differ) and produce a `IM_BANDFMT_UCHAR` image with the same number of bands as the input image, with 255 in every band element for which the condition is true and 0 elsewhere.

They may be combined with the boolean functions to form complex relational conditions. Use `im_max()` (or `im_min()`) to find out if a condition is true (or false) for a whole image.

Figure 2.2: Relational functions