第九章单幅图像深度重建 Depthmap Reconstruction Based on monocular cues
第九章 单幅图像深度重建 Depthmap Reconstruction Based on Monocular cues
章节安排 基于单眼线索的深度重建 >Shape From Shading >Shape From Vanishing Point Shape From Defocus Shape From Texture 极秋私
章节安排 ▪ 基于单眼线索的深度重建 ➢ Shape From Shading ➢ Shape From Vanishing Point ➢ Shape From Defocus ➢ Shape From Texture
Shape From Shading
Shape From Shading
What is Shading? Well...not shadow... 西 We can't reconstruct shape from one shadow
What is Shading? ▪ Well… not shadow… ▪ We can’t reconstruct shape from one shadow…
What is Shading? Variable levels of darkness Gives a cue for the actual 3D shape There is a relation between intensity and shape 陶
What is Shading? ▪ Variable levels of darkness ▪ Gives a cue for the actual 3D shape ▪ There is a relation between intensity and shape
Shading Examples These circles differ only in grayscale intensity none flat gouraud phong Intensities give a strong“feeling”of scene 得 structure
Shading Examples ▪ These circles differ only in grayscale intensity ▪ Intensities give a strong “feeling” of scene structure
What determines scene radiance? ■ The amount of light that falls on the surface The fraction of light that is reflected (albedo) Geometry of light reflection >Shape of surface 0iPi >Viewpoint (Oe,Pe
What determines scene radiance? ▪ n
Albedo p -A property of the surface >Usually normalized1≥p≥0 Can be modeled as a single scalar for the entire surface or dependent on location Usually assumed to be a known scalar >Is this a ball with uniform albedo or is this a 2D circle with varying albedo?
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Surface Normal Convenient notation for surface orientation A smooth surface has a tangent plane at every point We can model the surface using the normal at every point 蘭
Surface Normal Convenient notation for surface orientation A smooth surface has a tangent plane at every point We can model the surface using the normal at every point
The Shape From Shading Problem Given a grayscale image >And albedo >And light source direction Reconstruct scene geometry Can be modeled by surface normals
The Shape From Shading Problem ▪ Given a grayscale image ➢And albedo ➢And light source direction ▪ Reconstruct scene geometry ➢Can be modeled by surface normals
