CSCI 363 Vision--Spring 2023

Exam 1 Review

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Topics for Exam 1:
This sheet is intended to help you prepare for the first midterm in this course. The exam will cover all lectures through Lecture 6, Readings 1 - 4, Assignments 1 and 2 and Labs 1 and 2. It will not cover Fourier Series or Transforms or Spatial Frequency analysis. The exam will be closed book and closed note, however you may bring one 8.5 x 11" sheet of paper with notes. The following list of topics should help you study for the exam.

1. Introduction to vision

Properties of light
The eye as a pinhole camera
Perspective projection
Vision as an ill-posed problem
Assumptions made by the visual system
Marr's approach to studying vision

2. Neurons

Major parts of a neuron and their functions.
Electrical properties of neurons and action potential generation.
Steps involved in neural signalling
Complexity of neural processing

3. Central Visual Pathways

Main pathway from retina to extrastriate cortex
Basic structure of retina, LGN and striate cortex
Optic nerve and optic chiasm
Layered structure of LGN and cortex
Columnar structure of the cortex (Ocular dominance and Orientation)
Retinotopic mapping
Two major processing streams (Dorsal and Ventral) and their functions

4. The Retina

Five major cell types in the retina and their properties
Photoreceptors: Rods vs. Cones
The fovea
Center-surround receptive fields
On and Off responses

5. Edge Detection

Human judgments of edge detection: Craik O'Brien illusion
Smoothing. Removing noise and examining different spatial scales.
Differentiation: Localization of edges
Detecting zero crossings
Convolutions in 1-dimension and 2-dimensions
Use of the Gaussian function for smoothing
Result of convolving with derivative of the Gaussian
Result of taking the Laplacian of the gaussian
Difference of Guassians
Discrete convolutions--how to convolve 1D and 2D discrete images with a discrete operator.
1D operators for convolution: Averaging, Differentiation, Second derivative

6. Matlab

Matlab matrices. Using ones( ) and zeros( ) functions
Accessing array values. Accessing ranges of values
Conditionals and for loops in MATLAB
Matrix operations
Using size( ), sum( ) and mean( ) functions
Working with gray-scale images
Working with color images

7. Primary Visual Cortex

Types of cells: Simple, Complex and End-stopped
Proposed Circuits for constructing cortical cells
Direction selectivity: Definition and Proposed circuit.
Ocular dominance columns and ocular preference.
Orientation columns
Blobs and interblobs
Hypercolumns
Cortical magnification

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Constance Royden--croyden@holycross.edu
Computer Science 363--Vision
Last Modified: February 17, 2023
Page Expires: February 17, 2024