Deformable Part Model 實現細節

Overview

Step 1. Compute filter responses to the feature pyramid

Each level of features (e.g. 46) is convolved with every stored part filters (e.g. 54), the result subsequently goes to the corresponding filter entry in model.symbols struct. Therefore each model.symbols{i}.score is a 1x46 cell.

Step 2. Apply deformation and structural rule

Deformation rule is applied first to each part filter (e.g. 54). New scores are saved to corresponding model.rules{i}.score, together with Ix and Iy

Structual rule is applied at last.

In current model, the number of structural rules equal to the number of component.

They are aggregated into one rule which is indicated by model.start.

Dynamic Prgramming is implemented during the realisation of structural rules

Step 3. Parse resulting scores to find optimal solution (can be multiple hypotheses)

Some Implementation Details

symbols <---> rules: 1-to1 correspondence

symbols 只有兩種：terminal 和nonterminal

terminal symbol refers back to one entry in filters. In other words, terminal == filter

Run Time Variables

1. model.symbols{i}.score: 第i個filter對所有特徵金字塔的響應。e.g. 1x46 cell。在filter_responses中被初次計算

2. model.rules{i}.[score | Ix | Iy]：應用第i條規則後的新的score值，以及位置資訊。

3. model.scoretpt： TBD

function symbol_score

 - 對Deformatable Rule，只是簡單的把新的score值放回symbols{i}.score中

 - 對Structure Rule，找出最大值(好像！)