4.1 Introduction
 4.2 VIPS packages
  4.2.1 Arithmetic
  4.2.2 Relational
  4.2.3 Boolean
  4.2.4 Colour
  4.2.5 Conversion
  4.2.6 Matricies
  4.2.7 Convolution
  4.2.8 In-place operations
  4.2.9 Frequency filtering
  4.2.10 Histograms and LUTs
  4.2.11 Morphology
  4.2.12 Mosaicing
  4.2.13 CImg functions
  4.2.14 Other
  4.2.15 IO functions
  4.2.16 Format functions
  4.2.17 Resample functions