reproducing sAP evaluation

[yanconglin]

Hi, Yichao, really nice work! Thanks for sharing the code.
I would like to know how you convert the AFM reuslts (other methods as well) into the npz format which is used in the mAPJ/SAP evaluation? Can you share this part? Currently I have trouble reproducing the reported results of AFM in your paper. The numbes I got are 4.7 6.5 7.6 (sAP on ShanghaiTech), which are ~20 (sAP10) lower than the ones in the paper (Table 2). I have checked that the afm lines and gt lines before the 'lcnn.metric.msTPFP' function are matched by visualization (check the figure below), so I was wondering why the afm result I got is so bad compare with the one in paper? Looking forward to your help!

Thanks in advance!

[yanconglin]

Update: guess I found the reason after a day.... After checking the afm code, I found the last column of the output mat (x1,y1,x2,y2,width) is width, instead of the ratio which is used to rank lines in the paper. After replacing last column with width/length, I got new results: mAPJ 23.3 (the same as yours), sAP10: 23.9 (slightly worse than 24.4 in paper). Any ideas on why this happens?

[zhou13]

If the error is relatively small (23.9 vs 24.4), I think it might be due to some subpixel error, e.g., pixels starting from 0 vs from 1 vs from 0.5. @HaozhiQi Any idea on this?

[yanconglin]

Another update: Currently the number I got on York is better than yours: (sAP10: 9.1 vs 3.5, mAPJ: 12.3 vs6.9). THis is abit confusing. Not sure where the problem is. Is it possible to realase all numbers (SAP 5 10 15 on both datasets for all methods)? Thanks a lot!

[zhou13]

It seems that your number on York might be reasonable. I will check and get back to you later.

[zhou13]

Sorry for the late reply. The code for evaluating York I am currently using is

lcnn/eval-mAPJ.py

Line 103 in fdbbf6b

def evaluate_afm(im_list, gt_list):

and

lcnn/eval-sAP.py

Line 35 in fdbbf6b

def line_score(path, threshold=5):

I check my code and plot and it seems to be right for me. The gt data I am using is at https://drive.google.com/file/d/1ijOXv0Xw1IaNDtp1uBJt5Xb3mMj99Iw2/view?usp=sharing. Let me know if you have any finding or anything more from me.

[yanconglin]

Cool. I will. Thanks for the reply!

[zhou13]

Feel free to reopen this issue if you have any update.

[yanconglin]

HI, Yizhao,

Sorry to bother you again.
Recently, I spent sometiem figuring out why the Wireframe approach has such a bad performance on sAP (3%-5%), and found a problem in sAP evaluation. By printing the output of the Wireframe, you will find that there are many duplicate lines with exactly the same endpoints, except that the order of endpoints are different. This leads to a lower sAP values. Once those duplicate lines are removed, I obtained a higher sAP values (6.8 | 9.0 | 10.4 on ShanghaiTech), which seem to be more reasonable. Similar observations on the York dataset. Not sure if you have the same observation? PLease let me know your findings. Thank you!

[zhou13]

Hi @yanconglin,

Thank you so much for your finding! I was also wondering the same problem for some time. I will investigate and update our results.

Best,
Yichao Zhou.