Introduction to Image Processing Course Notes Anup Basu, Ph.D. Professor, Dept of Computing Sc. University of Alberta

Introduction n Image formation In the human eye In the human eye In digital imaging systems In digital imaging systems n Color vs. Grayscale (B&W) imaging n Sampling and quantization n Formats for storing images n Imaging geometry (perspective transform) n Stereo imaging geometry n 3D Homogeneous transform

Image Formation n Human eye Cones --- sense bright light & color Cones --- sense bright light & color Rods --- sensitive to low light Rods --- sensitive to low light FOVEA FOVEA Logarithmic & relative brightness response Logarithmic & relative brightness response n Digital imaging systems (CCD cameras) AREA & LINEAR CCD arrays AREA & LINEAR CCD arrays Analog-to-digital (A/D) conversion Analog-to-digital (A/D) conversion Compound lenses (approximates pinhole) Compound lenses (approximates pinhole) Focal length, aperture & depth of field Focal length, aperture & depth of field

Color vs. Grayscale imaging n Color R,G,B representation R,G,B representation H,S,I representation H,S,I representation other representations other representations n Grayscale binary images (e.g., text ) binary images (e.g., text ) more than 2 levels more than 2 levels

Sampling & Quantization n Sampling Spatial vs. temporal Spatial vs. temporal Resolution Resolution n Quantization Grayscale images Grayscale images Color images Color images

Storage formats (uncompressed) n Bitmap n GIFF (graphic interchange file format) n TIFF (tag interchange file format) n rasterfile (Sun Microsystems) n ppm, pgm, pbm (portable …) n General format structure Header Header Body, containing pixel (picture element) values Body, containing pixel (picture element) values

Imaging geometry n Perspective transform n Other (approximate) transforms Orthographic Orthographic Scaled orthographic Scaled orthographic Paraperspective Paraperspective … n Calibration

Stereo geometry n Stereo camera separation n Left and right images n Estimating 3D from stereo n Human stereo perception (Graphics) n Computer stereo perception (Computer Vision) (Computer Vision)

Stereo geometry n Stereo camera separation n Left and right images n Estimating 3D from stereo n Human stereo perception (Graphics) n Computer stereo perception (Computer Vision) (Computer Vision)

2 & 3D Homogeneous Transforms n Scaling ; n Translation n Rotation n 2D homogeneous transforms n 3D homogeneous transforms