-
-
Notifications
You must be signed in to change notification settings - Fork 829
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
content of matches.txt in AliceVision #1700
Comments
This is my interpretation so far: #viewid1 #viewid2 // Read from the text file src/aliceVision/matching/io.cpp |
Thank you for your reply, Therefore how can we print the matches (visualize) between the features of the two images of each pair given matches.txt as the only input?? Sorry I am a newbie I use the command line version of alicevision without gui |
You also need the extracted features. The easiest way to visualize your results is in the Meshroom UI. Here are some more of my notes: Feature Extraction (SIFT)desc are binary files view_id.sift.feat -> table with the extracted features Reference The image origin (top-left corner) has coordinate (0,0)
view_id.sift.feat Matrix (without column title): x y scale orientation (to plot this, make y negative (*-1)) Scale: square/circle size ImageMatchingMatches all images (tree) 197018718 907017304 1638077662 which images are matched against each other. Example W X Y Z W will be matched with X, Y, Z, then X with Y and Z and so on |
Thank you again, So if I want to visualize keypoints in both images and connect the matched ones with lines I should find the correspodence between feature ids from matches.txt and coordinates from viewID1.sift.feat and viewID2.sift.feat respectively, multiply y by -1 and scale it with the scale factor? The feature idx is the line number in viewID.sift.feat? What is the option in meshroom ui to visualize matches on pictures? |
So if I want to visualize keypoints in both images and connect the matched ones with lines I should find the correspodence between feature ids from matches.txt and coordinates from viewID1.sift.feat and viewID2.sift.feat respectively, multiply y by -1 yes and scale it with the scale factor? no, the scale is the scale property of the feature and orientation the orientation property. The position of the feature is just represented by x y. You can find some background info on scale and orientation here: https://www.vlfeat.org/overview/sift.html The feature idx is the line number in viewID.sift.feat? From what I can tell yes. (I am not the expert on this, I feel more at home with Meshroom ;) ) To familiarize yourself with the inner workings, I´d recommend you to take a look at Meshroom: What is your goal? To code your own viewer? |
Thank you for your answer, yes I try to code a viewer and when I plot the matches x,y in the image mosaic (composed by the two images of the pair) I get lines extending outside the borders of the two images , I tried to plot y,x and I get all keypoints inside the mosaic so I am wondering if the correct order of the coordinates is first y second x? I assumed that because in the viewID.sift.feat I see values of x coordinates exceeding the dimension of the picture in px and seem reasonable for y if I am not mistaking |
Yes, that is possible. I just wrote it down from memory :) |
Hello,
what is the format of the content of matches,txt I get from feature matching with alicevision from command line?? :
(example)-->
250654938 687988815
1
sift 749
19 23
1 2
40 56
104 122
12 18
9 13
42 97
13 36
74 87
329 280
22 46
75 137
62 105
88 126
102 138
455 471
94 112
126 127
117 149
105 220
112 187
469 516
161 196
the first line is the image pair ID ok and the matches between the images of the pair are after the line containing "sift" keyword,
but what is the exact sequence of the coordinates? the first line is for first image, the second line for the second image, the third is for first image , the fourth is for second image and so on? or are in different order??
The text was updated successfully, but these errors were encountered: