tailieunhanh - Lecture Digital image processing - Lecture 32: Object Recognition

This chapter presents the following content: What is object recognition? pattern classes, pattern recognition, object classifier, structural methods, decision theoretic methods, image understanding, define the image objects representation mechanism. | Digital Image Processing CSC331 Object Recognition 1 Summery of previous lecture image understanding Define the Image objects representation mechanism Use of the segmentation representations boundary based segmentation region based segmentation Description boundary based segmentation region based segmentation 2 Todays lecture What is object recognition? Pattern classes Pattern recognition Object classifier Structural methods Decision theoretic methods 3 Patterns and features Pattern classes: a pattern class is a family of patterns that share some common properties Pattern recognition: to assign patterns to their respective classes Three common pattern arrangements used in practices are Vectors Strings Trees Patterns and Pattern Classes 5 6 Basic object recognition flowchart Sensor Feature generation Feature selection Classifier design System evaluation 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Matching Shape Numbers Direction numbers for 4-directional chain code, and 8-directional chain code 0 1 2 3 0 1 2 3 4 5 6 7 21 Matching Shape Numbers Digital boundary with resampling grid superimposed 22 Matching Shape Numbers All shapes of order 4, 6,and 8 Order6 Order8 Chain code: 0321 Difference : 3333 Shape no. : 3333 Chain code: 003221 Difference : 303303 Shape no. : 033033 Chain code: 00332211 Difference : 30303030 Shape no. : 03030303 Chain code:03032211 Difference :33133030 Shape no. :03033133 Chain code: 00032221 Difference : 30033003 Shape no. : 00330033 Order4 23 24 Matching Shape Numbers Advantages: 1. Matching Shape Numbers suits the processing structure simple graph, specially becomes by the line combination 2. Can solve rotation the question 3. Matching Shape Numbers mostly to the graph outline, Shape similarity also may completely overcome 4. The Displacement question definitely may overcome 25 Matching Shape Numbers Disadvantages : 1. It can not uses for a hollow structure 2. Scaling is a shortcoming which needs to change, perhaps coordinates the alternative . | Digital Image Processing CSC331 Object Recognition 1 Summery of previous lecture image understanding Define the Image objects representation mechanism Use of the segmentation representations boundary based segmentation region based segmentation Description boundary based segmentation region based segmentation 2 Todays lecture What is object recognition? Pattern classes Pattern recognition Object classifier Structural methods Decision theoretic methods 3 Patterns and features Pattern classes: a pattern class is a family of patterns that share some common properties Pattern recognition: to assign patterns to their respective classes Three common pattern arrangements used in practices are Vectors Strings Trees Patterns and Pattern Classes 5 6 Basic object recognition flowchart Sensor Feature generation Feature selection Classifier design System evaluation 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Matching Shape Numbers Direction numbers for 4-directional chain code, and 8-directional chain