2016-12-07 02:43:50 -0600 | commented answer | Documentation for opencv_annotation yes, that's what I was thinking. a nice improvement would be to resize each rectangle after drawing it on image, before pressing C to confirm it. in fact, it's not easy to crop image with rectangle at first attempt. using dragable corners to size properly area of interest, would make things easier. do you think it may possible? thanks for your patience and support. |
2016-12-05 09:43:15 -0600 | commented answer | Documentation for opencv_annotation one more question: if I stop the process, by pressing ESC, after labelling N images and restart it, does it begin again from first image or does it continue from image N+1? |
2016-12-05 09:14:30 -0600 | commented answer | Documentation for opencv_annotation thanks a lot, it worked. I see you've added a revision to your original post, I'm glad of having been useful with my question :))))) thanks again. |
2016-12-03 10:58:47 -0600 | commented answer | Documentation for opencv_annotation folder exists, of course and has right name |
2016-12-03 10:57:53 -0600 | commented answer | Documentation for opencv_annotation hi. I wrote the following code: I used the same structure for /data, a local folder. absolute paths seem correct but I get why so? |
2016-12-03 05:18:41 -0600 | commented question | A Haar classifier for trees in satellite image: how to generate positive samples? I have two problems:
thus, I take every image and generate 80 samples (in average) by moving a fixed window along image itself. Finally, I label each window as positive or negative. |
2016-12-03 05:02:06 -0600 | commented question | A Haar classifier for trees in satellite image: how to generate positive samples? thanks for your answer. actually, the images I included in post are not the output of any cropping operation. they are just two samples that I labelled as positive, since they contain a tree for the greatest part of its surface in image. what worries me is the greatest variance across trees' shapes: just considering Rome's case, you can encounter maritime pines, cypresses (which appear as small spots when seen from above), oaks... do you agree with me in saying that this variance could be a problem? would you propose any other path to a tree detector, apart from Haar classifier? thanks |
2016-12-03 04:28:33 -0600 | commented question | A Haar classifier for trees in satellite image: how to generate positive samples? yes, sure. I've edited post adding three examples of positive samples: 1. a tree completely contained in square 2. a tree comprised in an agglomerate 3. a tree completely contained in square, with pieces of roofs and streets |
2016-12-02 13:47:49 -0600 | received badge | ● Editor (source) |
2016-12-02 13:18:51 -0600 | asked a question | A Haar classifier for trees in satellite image: how to generate positive samples? Hello everyone. I'm trying to train a Haar classifier for detecting trees in satellite images. While it's almost easy to generate negative samples (it's sufficient to cut parts containing streets or buildings without any tree), I find it difficult to generate positive samples. I've read (in this forum, too) that I should crop positive sample containing only desired object (a tree, in my case); anyway, it's hard to obtain this result with satellite images since:
I've tried to generate a certain number of random square samples from satellite image. I've chosen size of squares in order to contain, in average, a tree almost completely. Then, I parsed samples one by one, separating them in negative and positive sets. I've stated that a sample is positive if it contains at least a tree at 70% of its surface, by visual inspection. Anyway, detection results are awful. My questions are;
I even tried to browse web to look for a dataset of trees extracted from satellite images, but I haven't found anyone. Can you suggest one? Thanks for support. EDIT: Here are some examples of positive samples (80x80 pixels) I've used
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2016-11-29 11:26:24 -0600 | commented answer | Cascade Training: killed and bad_alloc I'm using some C++ code to generate opencv_train_cascade command I get the "Killed error" and I tried to add -nonsym -mem 512, but I got It seems that such option is not accepted in training command (I haven't found it on official page, indeed). Any suggestion? thanks |