logging in or signing up midterm review 1 Brainy007 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINTLite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 68 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: November 02, 2007 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript CS248 Midterm Review: CS248 Midterm Review Michael Green and Sean Walker (based on the work of previous TAs)CS248 Midterm: CS248 Midterm Mon, November 1, 7-9 pm, Gates B01 Mostly “short answer” questions Keep your answers short and sweet! Covers lectures up to Tuesday, Oct 26 plus taxonomy from start of last lecture Review session slides available from class website Exam is closed book, closed notesRaster Displays, Resolution, Perception: Raster Displays, Resolution, Perception CRTs 3 phosphors for “red”, “green”, and “blue” Triads and shadow mask Measures of spatial resolution physical vs. addressable resolution Human spatial frequency sensitivity: Human spatial frequency sensitivity Sensitivity highest in fovea Frequency sensitivity Phase sensitivity (Vernier acuity) Temporal sensitivity Flicker (50-70Hz) Perceived motion 12 Hz = cartoons, 24 Hz = film, 60 Hz = videoRaster Displays, Resolution, Perception: Raster Displays, Resolution, Perception Human intensity sensitivity Response to intensity is nonlinear Gamma in cameras, CRTs Gamma correction Raster Displays, Resolution, Perception: Raster Displays, Resolution, Perception Sample (easy) question: A scene is photographed with a TV camera with gamma=0.5 and displayed on a CRT with gamma=2.4. If we want system gamma to be 1.0, we should do gamma correction with what exponent? Color: Color Perception of color Humans are trichromat Three cones sensitive to “red”, “green”, and “blue” Overlapping response curves Know their general shapes! Color matching Color matching experiment Color spaces: Color spaces Linear colorspaces , , space (perceptual stimulus) R, G, B space X, Y, Z space Non-linear colorspaces HSV Spectral locus Gamut of reproducible colorsColor: Color Sample questions: 1. Circle those colors that are not reproducible with a single monochromatic light Red Yellow Blue Magenta White GreenColor: Color Sample questions: 2. If you had a special CRT that could produce pure spectral colors, how many spectral colors would you need to represent a normal RGB color gamut? How about the spectral locus?Sampling and Antialiasing: Sampling and Antialiasing The sampling and reconstruction pipeline: Prefiltering Sampling Resampling Reconstruction Aliasing in the frequency domain Filtering and convolution Duality: F(x)*G(x) <=> F(w)G(w)Sampling and Antialiasing: Sampling and Antialiasing Prefiltering vs. postfiltering Desirable filters for antialiasing Box, pyramid, gaussian, sinc Methods of antialiasing Supersampling: regular vs. stochastic Analytical antialiasingSampling and Antialiasing: Sampling and Antialiasing Sample questions: What is the result of convolving a 1-D box filter with itself? Which of the following would affect your choice of a reconstruction filter? pixel shape choice of prefilter actual size of display Rasterization: Rasterization Rasterization of lines DDA, incremental algorithm Rasterization of polygons Only pixels in the polygon Supersampling Patterns: understand its effect on the imageRasterization: Rasterization Sample question: If you rasterized this line using DDA, which pixels would get turned on?Digital Compositing: Digital Compositing What is compositing? The compositing approximation Conditions for validity Compositing algebra: Compositing algebraDigital Compositing: Digital Compositing Sample question: You are doing the special effects for a movie, and need to composite a computer generated object over a live background. Why should you use an 8-bit alpha matte rather than a binary (1-bit) matte, even if the computer-generated object is fully opaque?Transformations: Transformations Homogeneous coordinates – why? Matrices rotation, translation, scale, shear in 2D, 3D Know the form of each kind Geometric properties preserved/changed by each kind Composing transformations multiply matrices in reverse order Transformations: Transformations Sample questions Compute the 2D transform that translates an object centered at (-3,4) to the origin, then rotates it by +45o, then translates it to (10,5). What sequence of transforms would cause the triangle to change as shown below ?GOOD LUCK AND HAPPY HALLOWEEN!: GOOD LUCK AND HAPPY HALLOWEEN! You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
midterm review 1 Brainy007 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINTLite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 68 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: November 02, 2007 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript CS248 Midterm Review: CS248 Midterm Review Michael Green and Sean Walker (based on the work of previous TAs)CS248 Midterm: CS248 Midterm Mon, November 1, 7-9 pm, Gates B01 Mostly “short answer” questions Keep your answers short and sweet! Covers lectures up to Tuesday, Oct 26 plus taxonomy from start of last lecture Review session slides available from class website Exam is closed book, closed notesRaster Displays, Resolution, Perception: Raster Displays, Resolution, Perception CRTs 3 phosphors for “red”, “green”, and “blue” Triads and shadow mask Measures of spatial resolution physical vs. addressable resolution Human spatial frequency sensitivity: Human spatial frequency sensitivity Sensitivity highest in fovea Frequency sensitivity Phase sensitivity (Vernier acuity) Temporal sensitivity Flicker (50-70Hz) Perceived motion 12 Hz = cartoons, 24 Hz = film, 60 Hz = videoRaster Displays, Resolution, Perception: Raster Displays, Resolution, Perception Human intensity sensitivity Response to intensity is nonlinear Gamma in cameras, CRTs Gamma correction Raster Displays, Resolution, Perception: Raster Displays, Resolution, Perception Sample (easy) question: A scene is photographed with a TV camera with gamma=0.5 and displayed on a CRT with gamma=2.4. If we want system gamma to be 1.0, we should do gamma correction with what exponent? Color: Color Perception of color Humans are trichromat Three cones sensitive to “red”, “green”, and “blue” Overlapping response curves Know their general shapes! Color matching Color matching experiment Color spaces: Color spaces Linear colorspaces , , space (perceptual stimulus) R, G, B space X, Y, Z space Non-linear colorspaces HSV Spectral locus Gamut of reproducible colorsColor: Color Sample questions: 1. Circle those colors that are not reproducible with a single monochromatic light Red Yellow Blue Magenta White GreenColor: Color Sample questions: 2. If you had a special CRT that could produce pure spectral colors, how many spectral colors would you need to represent a normal RGB color gamut? How about the spectral locus?Sampling and Antialiasing: Sampling and Antialiasing The sampling and reconstruction pipeline: Prefiltering Sampling Resampling Reconstruction Aliasing in the frequency domain Filtering and convolution Duality: F(x)*G(x) <=> F(w)G(w)Sampling and Antialiasing: Sampling and Antialiasing Prefiltering vs. postfiltering Desirable filters for antialiasing Box, pyramid, gaussian, sinc Methods of antialiasing Supersampling: regular vs. stochastic Analytical antialiasingSampling and Antialiasing: Sampling and Antialiasing Sample questions: What is the result of convolving a 1-D box filter with itself? Which of the following would affect your choice of a reconstruction filter? pixel shape choice of prefilter actual size of display Rasterization: Rasterization Rasterization of lines DDA, incremental algorithm Rasterization of polygons Only pixels in the polygon Supersampling Patterns: understand its effect on the imageRasterization: Rasterization Sample question: If you rasterized this line using DDA, which pixels would get turned on?Digital Compositing: Digital Compositing What is compositing? The compositing approximation Conditions for validity Compositing algebra: Compositing algebraDigital Compositing: Digital Compositing Sample question: You are doing the special effects for a movie, and need to composite a computer generated object over a live background. Why should you use an 8-bit alpha matte rather than a binary (1-bit) matte, even if the computer-generated object is fully opaque?Transformations: Transformations Homogeneous coordinates – why? Matrices rotation, translation, scale, shear in 2D, 3D Know the form of each kind Geometric properties preserved/changed by each kind Composing transformations multiply matrices in reverse order Transformations: Transformations Sample questions Compute the 2D transform that translates an object centered at (-3,4) to the origin, then rotates it by +45o, then translates it to (10,5). What sequence of transforms would cause the triangle to change as shown below ?GOOD LUCK AND HAPPY HALLOWEEN!: GOOD LUCK AND HAPPY HALLOWEEN!