NMF Computer Demonstration Overview: Faces, Shapes, and Cars
This overview presents a demonstration of Non-negative Matrix Factorization (NMF) applied to various datasets, including facial images, random shapes, and car images. The training sets consist of 2429 examples, with specific focus on images like 19x19 centered faces, geometric shapes (squares, rectangles, circles), and cars captured at various orientations. Key parameters include rank, iterations, and output analysis for basis images. This demonstration highlights the practical applications of NMF in analyzing and reconstructing image data while addressing issues and choices in the methodology.
NMF Computer Demonstration Overview: Faces, Shapes, and Cars
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Presentation Transcript
NMF Demo: Lee, Seung Bryan Russell 6.899 Computer Demonstration
Overview • Training sets • Faces • Random noise • “Block world” • Cars • Issues/Choices • Rank • Number of iterations • Dataset
NMF: Equations • Objective Function:
NMF: Equations • Update equations:
Faces • Training set: 2429 examples • First 25 examples shown at right • Set consists of 19x19 centered face images
Faces • Basis Images: • Rank: 49 • Iterations: 50
Faces Original = x
Faces • Basis Images • Rank: 49 • Iterations: 500
Faces Original = x
Random • Training set: 2429 examples • First 25 examples listed to the right • Gray-level values generated randomly
Random • Basis Images • Rank: 49 • Iterations: 50
Random Original = x
Random • Basis Images • Rank: 49 • Iterations: 500
Random Original Output
Random Originals (1-25) Output (1-25)
“Blocks” • Training set: 2429 examples • First 25 examples listed to the right • Three “shapes”: squares, rectangles, and circles • Shapes centered at two points in image
“Blocks” • Basis Images • Rank: 25 • Iterations: 408
“Blocks” Original = x
“Blocks” Originals (1-25) Output (1-25)
“Blocks” Output (1-25)
“Blocks” • Basis Images • Rank: 49 • Iterations: 345
“Blocks” Originals (1-25) Output (1-25)
“Blocks” Output (1-25)
Cars • Training set: 200 examples • First 25 examples shown at right • Set consists of car images taken at various orientations
Cars • Basis Images • Rank: 49 • Iterations: 310 • Number of samples: 200
Cars Originals (1-25) Output (1-25)
Thanks! • CBCL for providing face and car images
For code and data, go to: www.ai.mit.edu/~brussell/courses/6.899/nmf