Results of classification - Third Week

In my third week I began testing the object classification code looking on accuracy and time of processing. These are the results:

Using ORB Features

For k (number of clusters, centers or codewords) = 64

Time for getting all the local ORB descriptors of the 356 training images was 00:00:09.533.
Time for k-means with ORB and k=64 was 00:00:16.574.
Time for getting VLAD global descriptors for k=64 and the 356 training images was 00:00:58.26.
Time for calculating the SVM for k=64 was 00:00:13.407.
Time for getting VLAD descriptors for k=64 and the 179 testing images was 00:00:28.784.
Time for classifying was 00:00:0.001.
Accuracy was 76.705%.

For k=128

Time for k-means with ORB and k=128 was 00:00:20.
Time for getting VLAD global descriptors for k=128 and the 356 training images was 00:02:24.651.
Time for calculating the SVM for k=128 was 00:00:34.648.
Time for getting VLAD descriptors for k=128 and the 179 testing images was 00:01:09.031.
Time for classifying was 00:00:0.001.
Accuracy was 80.114%.

For k=256

Time for k-means with ORB and k=256 was 00:00:59.893.
Time for getting VLAD global descriptors for k=256 and the 356 training images was 00:02:58.63.
Time for calculating the SVM for k=256 was 00:01:12.594.
Time for getting VLAD descriptors for k=128 and the 179 testing images was 00:01:27.856.
Time for classifying was 00:00:0.003.
Accuracy was 77.841%.

Using SIFT features

For k=64

Time for getting all the local SIFT descriptors of the 356 training images was 00:01:45.578.
Time for k-means with SIFT and k=64 was 00:01:33.133.
Time for getting VLAD global descriptors for k=64 and the 356 training images was 00:05:16.315.
Time for calculating the SVM for k=64 was 00:00:48.826.
Time for getting VLAD descriptors for k=64 and the 179 testing images was 00:02:05.115.
Time for classifying was 00:00:0.002.
Accuracy was 89.773%.

For k=128

Time for k-means with SIFT and k=128 was 00:02:51.927.
Time for getting VLAD global descriptors for k=128 and the 356 training images was 00:10:41.265.
Time for calculating the SVM for k=128 was 00:01:55.241.
Time for getting VLAD descriptors for k=128 and the 179 testing images was 00:04:17.92.
Time for classifying was 00:00:0.004.
Accuracy was 89.773%.

For k=256

Time for k-means with SIFT and k=256 was 00:05:23.914.
Time for getting VLAD global descriptors for k=256 and the 356 training images was 00:16:36.843.
Time for calculating the SVM for k=256 was 00:04:01.465.
Time for getting VLAD descriptors for k=256 and the 179 testing images was 00:05:41.41.
Time for classifying was 00:00:0.016.
Accuracy was 87.5%.

Results may be different using a SVM with other kernel like RBF. I only used a Linear kernel. Accuracy was calculated as number of correctly classified images / total number of images (in the testing set).