So far, I tested Pastec in terms of the quality of image matching. In this posting, I tested speed of adding and searching.
Adding images to index
Firstly I added 100 images. Adding 100 images took 48.339 seconds. Then I added all directory from 22 to 31. Those images are uploaded to wikimedia commons from 2013.12.22 to 2013.12.21.
Average time for adding an image was around 0.46 second and it didn’t increased as the index grows. Most of the time for adding an image is extracting features.
I saved the index file for 100 images, from 22 to 26, and from 22 to 31. The size were 8.7mb, 444.1mb, and 935.8mb respectively.
I loaded the index file for 100 images. And searched all 100 images that are used to add.
Searching took 1m14.781s. Since it is 100 images, average time to add one image was 0.74 second.
Then I loaded the index file that contains index for 39,183 images in the directory from 22 to 26.
This time, average time for searching one image was 0.95 second.
Then I loaded the index file that contains index for 84,340 images that are in the directory from 22 to 31.
Searching performed for the same images from 22 to 26. Average time for searching was 1.3 seconds.
- Adding an image took 0.47 second.
- Adding time didn’t varied by index size.
- Searching an image varied by index size.
- When the index size was 100, 39183, and 84340, searching time was 0.74, 0.95, and 1.3 seconds, respectively.
In the chart, y-axis is time in milliseconds. Around 0.6 second is likely to be for reading an image and extracting features. And searching time will be increased in proportion to the size of index.