Questions tagged [yolo]

For questions related to the family of models known as YOLO (which stands for "You Only Look Once"), which were proposed by Joseph Redmon et al. There are at least three YOLO models (versions 1, 2, and 3).

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11 votes
3 answers
12k views

Is it difficult to learn the rotated bounding box for a (rotated) object?

I have checked out many methods and papers, like YOLO, SSD, etc., with good results in detecting a rectangular box around an object, However, I could not find any paper that shows a method that learns ...
9 votes
1 answer
3k views

In YOLO, what exactly do the values associated with each anchor box represent?

I'm going through Andrew NG's course, which talks about YOLO, but he doesn't go into the implementation details of anchor boxes. After having looked through the code, each anchor box is represented by ...
  • 209
6 votes
2 answers
2k views

What's the role of bounding boxes in object detection?

I'm quite new to the field of computer vision and was wondering what are the purposes of having the boundary boxes in object detection. Obviously, it shows where the detected object is, and using a ...
5 votes
1 answer
677 views

In YOLO, when is $\mathbb{1}_{i j}^{\mathrm{obj}} = 1$, and what are the ground-truth labels for $x_i$ and $y_i$?

I'm trying to implement a custom version of the YOLO neural network. Originally, it was described in the paper You Only Look Once: Unified, Real-Time Object Detection (2016). I have some problems ...
  • 276
5 votes
0 answers
1k views

What are the differences between Yolo v1 and CenterNet?

I recently read a new paper (late 2019) about a one-shot object detector called CenterNet. Apart from this, I'm using Yolo (V3) one-shot detector, and what surprised me is the close similarity between ...
  • 298
4 votes
1 answer
237 views

What is a unified neural network model?

In many articles (for example, in the YOLO paper, this paper or this one), I see the term "unified" being used. I was wondering what the meaning of "unified" in this case is.
3 votes
1 answer
143 views

YOLO - are the anchor boxes used only in training?

another question in YOLO. I've red about how YOLO adjusts anchor boxes by offsets to create the final bounding boxes. What I do not understand, is when YOLO does it. Is it being done only during the ...
  • 137
3 votes
1 answer
274 views

How to treat (label and process) edge case inputs in machine learning?

In every computer vision project, I struggle with labeling guidelines for border cases. Benchmark datasets don't have this problem, because they are 'cleaned', but in real life unsure cases often ...
  • 101
3 votes
2 answers
3k views

Calculation of FPS on object detection task

How to calculate mean speed in FPS for an object detection model like YOLOv3 or YOLOv3-Tiny? Different object detection models are often presented on charts like this: I am using the DarkNet ...
3 votes
0 answers
47 views

How are Ground truth provided to each Pyramid map in RetinaNet or YOLOv3 Paper? How is the mapping of Feature Pyramids done to Ground Truth

SO the YOLO V3 and RetinaNet both uses the Feature pyramids which look something like this: (except b and e which have one ...
  • 233
3 votes
0 answers
32 views

If random rotations are included in the data augmentation process, how are the new bounding boxes calculated?

When studying bounding box-based detectors, it's not clear to me if data augmentation includes adding random rotations. If random rotations are added, how is the new bounding box calculated?
3 votes
1 answer
773 views

How can I incrementally train a Yolo model without catastrophic forgetting?

I have successfully trained a Yolo model to recognize k classes. Now I want to train by adding k+1 class to the pre-trained weights (k classes) without forgetting previous k classes. Ideally, I want ...
  • 73
2 votes
2 answers
73 views

How does YOLO handle non-class objects?

I have been reading more about computer vision and I'm bothered by YOLO and similar deep learning architectures. The thing I am confused about is how non-class image sections are dealt with. In ...
2 votes
1 answer
635 views

How are IOUs for ground truth boxes in YOLO calculated?

I know how IOU works during detection. However, while preparing targets from ground-truth for training, how is the IOU between a given object and all anchor boxes calculated? Is the ground truth ...
  • 73
2 votes
1 answer
77 views

Preparing data set for the YOLO algorithm

Hi I am working on a project which requires the You Only Look Once algorithm in order to classify and localise objects within images. I have to prepare my dataset (which has 2 classes, and predicts 6 ...
2 votes
3 answers
289 views

Would YOLO be able to detect objects in "different" positions?

I have the following question about You Only Look Once (YOLO) algorithm, for object detection. I have to develop a neural network to recognize web components in web applications - for example, login ...
  • 21
2 votes
2 answers
177 views

What YOLO algorithm can I use for images with noise as I will implement it in real time?

I want to detect drivers with or without seatbelts at crossroads. For that, as it is real-time, I am going to use the YOLO algorithm/model. For training data sets (the images) I need to collect, I ...
2 votes
2 answers
2k views

How can I detect thin objects (like pens and pencils) without a bounding box but only 2 endpoints and the orientation?

I am looking to detect thin objects, like pens, pencils, and surgical instruments. The bounding box is not important, but I am looking to see if I can train a model to detect both the object as well ...
2 votes
0 answers
34 views

Do filters have as many layers as the depth of the input in CNNs? [duplicate]

Firstly as an example here is the architecture of YOLOv2 I am trying to understand the depth of an output of a convolutional layer. For example, the first convolutional layer has the shape 3x3x32. So ...
2 votes
1 answer
50 views

Data scan not making sense for coco dataset

I am doing a simple scan to see how dataset size affects training. Basically, I took 10% of the coco dataset and trained a yolov3 net (from scratch) to just look for people. Then I took 20% of the ...
2 votes
0 answers
37 views

YOLO 9000 about Better Stronger

In this paper, YOLO has three features compared to YOLO v1. This question is about Better and Faster. In the Better section, there are many techniques such as Batch Norm, Anchor Box and so on. In the ...
2 votes
0 answers
592 views

How can I train YOLO with the COCO dataset?

I am trying to implement the original YOLO architecture for object detection, but I am using the COCO dataset. However, I am a bit confused about the image sizes of COCO. The original YOLO was trained ...
2 votes
1 answer
455 views

How to detect multiple playing cards of the same class with a neural network?

I want to train an AI to detect the class (i.e. suit and rank) of playing cards. Playing cards from different decks may use slightly different shapes or colors to represent these attributes, and I ...
1 vote
1 answer
2k views

Can YOLO detect large objects?

I have a rather basic question about YOLO for bounding box detection. My understanding is that it effectively associates each anchor box to an 8-dimension output. During testing, does YOLO take each ...
  • 227
1 vote
2 answers
1k views

What are the reasons behind slow YOLO training?

I'm testing out YOLOv3 using the 'darknet' binary, and custom config. It trains rather slow. My testing out is only with 1 image, 1 class, and using YOLOv3-tiny instead of YOLOv3 full, but the ...
  • 1,213
1 vote
1 answer
34 views

How to identify and diferentiate several edge lines of an object?

I want to create an AI to detect and identify certain edge lines on my image. The input image is a locker key, and I want to know the exact position of certain edges. Sample input image: Sample ...
  • 111
1 vote
2 answers
359 views

Get object's orientation or angle after object detection

I'm trying to get a detected car's orientation when object detection is applied. For instance, when we apply object detection on a car and get a bounding box, is there any ways or methods to calculate ...
  • 963
1 vote
1 answer
106 views

Object detection: combine many classes into one?

I am trying to train a model that detects logos in documents. Since I am not really interested in what kind of logo there is, but simply if there is a logo, does it make sense to combine all logos ...
  • 111
1 vote
1 answer
846 views

How to label training data for YOLO

I am having a question on how to label training data for YOLO algorithm. Let's say that each label Y, we need to specify $[P_c, b_x, b_y, b_h, b_w]$, where $P_c$ is the indicator for presence (1=...
1 vote
1 answer
143 views

Why is my fine-tuned YOLO model detecting other objects as a human?

I am new to deep learning and computer vision. I have a problem where I use the YOLO to detect objects. For my problem, I just want to recognize 1 human only. So, I changed the final YOLO's layer (...
  • 111
1 vote
0 answers
26 views

Training with extremely imbalanced Dataset

I have a object detection problem which has extremely imbalanced dataset. Lets say there is only one class to detect, say apple or not apple. This detection network will be used in a real case ...
  • 11
1 vote
1 answer
185 views

How does YOLO detect the object when the object is in multiple grid cells?

I have been reading various articles and watching videos on YouTube, but I can't seem to understand one thing. How does YOLO make a bounding box for an object if it is in multiple grid cells? For ...
1 vote
0 answers
59 views

Different equations for Yolov3 in courses/ articles and Darknet GitHub code?

I am confused by the equations for bounding boxes I find online. Some articles say that box_width = anchor_width * exp(residual_value_of_box_width)) and the ...
1 vote
0 answers
26 views

In anchor based object detection, why don't the anchors share the same weights?

After reading about YOLO V3 and Faster R-CNN, I don't understand why the weights for the regression head aren't the same across all boxes of the same size. Given that the backbone of these systems is ...
1 vote
0 answers
179 views

What are the main differences between YOLOv3 and RetinaNet object detection algorithms?

I am looking at a certain project that compares performance on a certain dataset for an object detection problem using YOLOv3 and RetinaNet (or the "SSD_ResNet50_FPN" from TF Model Zoo). ...
  • 128
1 vote
0 answers
12 views

Aggregating 2D object detections into 3D object detections

I have a data set of 3D images with some bounding box annotations. The images are too large to train something like YOLO 3D (would run out of memory), so I instead created slices of the 3D images with ...
1 vote
0 answers
29 views

How is the shape of the anchor boxes predefined in YOLO algorithm?

I am not sure if I really understand how anchor boxes are defined. As far as I understand, in YOLO algorithm you define a set of "good" shapes (anchor boxes) that may contain the object you ...
0 votes
1 answer
39 views

Taxonomy of terms in DL [closed]

I am trying to teach myself DL and among other difficulties I found it quite challenging to structurize a very basic terminology vocabulary especially when it includes not only theoretical stuff but ...
  • 137
0 votes
1 answer
40 views

Darknet as a part of Yolo v3

I am pretty new to ML and my question may look strange. Especially the last part of it. 1)As far as I understand Darknet53 is an integral part of Yolo just as Resnet50 is a part of R-CNN Am I right? 2)...
  • 137
0 votes
1 answer
231 views

YOLO - does the Intersection over Union is actually a part of Non Maximum Suppresion

In the Stack Overflow thread Intersection Over Union (IOU) ground truth in YOLO they say that in YOLO actually the IoU (intersection over union) is used twice: during training to compare ground truth ...
  • 137
0 votes
1 answer
132 views

Are the output dimensions of the first and second convolutional layer in YOLO paper correct?

I was reading the last version of the YOLO paper available in Arxiv, and I don't fully understand the output dimensions (I understand width and height, but not depth) of the first and second ...
0 votes
1 answer
40 views

Multiple labels for the same rectbox?

My goal is to identify the horse in a photo. I'm dealing with about 500 unique horses. My feeling is that the best way to distinguish one horse from another is by its face. So I trained Yolov5 ...
0 votes
1 answer
36 views

Should I label static objects on video dataset?

I'm using nvidia Transfer Learning Toolkit to detect cars in some video frames. I found some dataset (for example https://www.jpjodoin.com/urbantracker/dataset.html and https://www.kaggle.com/...
0 votes
1 answer
166 views

Object Detection: Can I modify this script to support larger images (Scaled YOLOv4)?

I am looking at training the Scaled YOLOv4 on TensorFlow 2.x, as can be found at this link. I plan to collect the imagery, annotate the objects within the image in VOC format, and then use these ...
  • 119
0 votes
1 answer
24 views

Can YOLOv3 architecture be clearly separated into feature extractor and classifier parts?

I am new to machine learning and am confused about whether its architecture has clearly defined boundaries which demarcate the feature extraction and classification part. Or is it that it classifies ...
0 votes
0 answers
12 views

Machine/Deep learning model for object labeling in Check Images?

I am currently facing an issue with identifying sections within a check images, something like object identification. Initially it seemed I could use YOLOv5, because it is good with object detection. ...
0 votes
0 answers
13 views

Train YOLO on SKU110K data set

I am new to the deep learning domain. I am working on a project that requires me to create bounding boxes around the products on the shelf. Something like this: I want the program to detect the ...
0 votes
0 answers
44 views

Change fully connected layer for YOLO v4 network , analogous to GoogLeNet (matlab)

I have a challenging task here. I would like to train a YOLOv4 - network, but with the following adjustment: In my previous implementation of CNNs, a pre-trained network was loaded, and the last layer ...
  • 131
0 votes
0 answers
25 views

What object detection algorithm is the best for my particular problem?

I am trying to write a program to put a bounding box around dead fish, and not the live ones, in a video. I have minimal data (~5k frames and ~7k objects in total ) and it is VERY low quality (poor ...
  • 15
0 votes
1 answer
122 views

Object Classification: How to decide which detected region is a RoI for classification?

I am working on a project where I am working on the Flickr-47 dataset to do logo detection and classification. My approach is to first finetune a YOLO v5 model with high recall to detect as many "...