# Image Analysis Using Human Body Geometry and Size Proportion Science for Action Classification
## 4 Results and Discussion
### Discussion
All of the 45 actions are misclassified as Standing. Rule (12) is defined for classifying \"Walk\" action i.e., \(D_{BLR}(\theta)>15\) AND \(SHR>0.25\). The second part of the rule says that the step size to height ratio should be greater than 0.25. During the walk, the size of step changes and misclassification case is for those frames where the posture of step is such that it is getting towards 0. Rule (11) is defined for a Standing case whose second part says \(SHR<0.25\). Thus, as the step size of the person gets  
Figure 8: Abnormal “SHTW” actions. (**a**) Misclassification example; (**b**) Un-Classification example. Figure 7: Abnormal “SHSW” actions. (**a**) Misclassification example; (**b**) Un-Classification example. shorter, therefore, the posture matches the standing posture and it may be taken as misclassification. The example images of those are shown in Figure 9a,b. \"Standing\" is the next action whose classification statistics are shown in Table 10. A total of 419 images are used for testing purposes which are contributed by all of the eight actors. The number of classified images is 406 while 13 are un-classified. From the classified images, 361 are correctly classified while 45 are misclassified. Out of 45, 38 are misclassified as SHTW and seven as Walk. The classification rule for \"Standing\" action is given in (11) stating that three of the conditions need to be fulfilled for the prescribed class. The misclassification to SHTW is unfulfillment of portion of (11) i.e., \(d_{TLR}(\theta)<10\text{ AND }D_{TLR}\leq handSize\). These are the images in the dataset where the actor is standing in a bent position. The bent is more than the normal position and is thus closer to bending action than standing. This posture e.g., in Figure 10a resulted when \(D_{TLR}\) greater than handSize as the Top left point moves farther from the top right point. The second condition also gets failed i.e., \(d_{TLR}(\theta)<10\). As a result, rule (15) gets applied which classifies the action as SHTW. The second case where the images are misclassified as \"Walk\" doesn't fulfill the second half of rule (11) i.e., \(SHR<0.25\). Figure 10b shown below is the example of those misclassified action images. It is clear from Figure 10b that the position of feet of the actor is such that it gives the same \"Walk\" like step i.e., \(SHR>0.25\), which is a condition of rule (12) for \"Walk\" action. The next action under discussion is \"BHSW\" for which a total of 205 test images are collected from eight different actors. The classified images are 186 while 19 of them got un-classified. From 186 classified actions, 175 are correctly classified and the remaining 11 are misclassified to \"BHTW\". The classification rule for BHSW is defined in (17). The classification rule for BHSW has two parts i.e., (i) Condition fulfilling top left and top right angles with respect to centroid of the human body, \(TL(\theta)>125\text{ AND }TR(theta)<55\), (ii) The distance between top left and top right points, \(D_{TLR}>1.5*armLength\). Figure 11a is an example of misclassification of \"BHSW\" as \"BHTW\" as both \(TL(\theta)\)  
Figure 10: Abnormal “Standing” actions. (**a,b**) Misclassification examples. Figure 9: Abnormal “Walk” actions. (**a,b**) Misclassification examples. and \(TR(theta)\) do not fulfill the required criteria and the conditions fall in rule (18) which is for \"BHTW\". The \"BHSW\" actions that are un-classified by the proposed technique neither fulfill rule (17) for \"BHSW\" nor rule (18) for \"BHTW\". Figure 11b,c are examples of un-classified actions. Figure 11b doesn't fulfill the first part of rule (17) so it can't be classified to \"BHSW\", although the first part of rule (18) is true i.e., \((TL(\theta)>97.5\) AND \(TL(\theta)\leq 125)\) AND \((TR(theta)<82.5\) AND \(TR(theta)\geq 55))\), but the second half of the rule i.e., \(D_{TLR}\leq 1.5*armLength\) is not fulfilled so resulting them as un-classified. The second Un-Classification example for \"BHSW\" is Figure 11c.