Questions tagged [yolo]

"You Only Look Once", a Deep Learning-based object recognition algorithm available in several different software implementations.

Filter by
Sorted by
Tagged with
1
vote
0answers
6 views

What is the difference between these error metrics in object detection

I am wondering what is the difference in these error metrics (and what they are) in object detection: mAP_0.5:0.95, mAP_0.5, recall, precision
0
votes
0answers
8 views

Yolov- 3: How are features / detection at 3 different level arranged to give 1 final output?

In yolo-v3, at layer numbers 82,94,106, detection are made. What if Same object was detected in all those places? Grids were different due to no of grids ...
1
vote
0answers
15 views

Does it help to provide training samples with no target objects in object detection?

I am training a Yolo for object detection. I was wondering if it will help to provide images with no instances of the target object present. If so, what would the VOC label of such an instance look ...
1
vote
1answer
34 views

Does the Object you Want to Classify have to be in a Cluttered Background in Yolo?

I'm trying to classify plant diseases with the plant village dataset, shown in the image above. These images are all very consistent, with exactly one leaf and similar backgrounds. However, I am ...
1
vote
0answers
27 views

YoloV3: Training set, true label boxes vs anchor boxes

I understand the anchor boxes as a set of boxes that based on a comprehensive exploration of the data ( all the true bonding boxes) best describe the variable sizes of all true boxes in the training ...
0
votes
0answers
15 views

Model Suggestions: Object Tracking for Ants

I hope it's going well. For some time now I have been training YOLOv3 to detect the bodies and heads of bull ants, a large type of ant from the genus Myrmecia. The goal is to be able to extract the ...
1
vote
0answers
62 views

How to add labels to an already trained Yolo model?

I'm learning ML and I'm exploring object detection and classification. I discovered Yolo few months ago and it's impressively efficient and accurate. There are several pre-trained Yolo models on the ...
2
votes
1answer
179 views

What are “Grids” and Detection at different scales" in YOLOV3?

I've recently started working with Yolov3 and the more I go in depth, the more confused I get. In the simplest terms what I think about YOLOV3 ...
1
vote
1answer
315 views

Darknet and Data Augmentation

In the darknet deep learning framework .cfg files we see parameters like angle, saturation, exposure These parameters are used ...
3
votes
1answer
121 views

Why use multiple anchor boxes with the same positions in a multi-box detector?

What is the benefit of using multiple anchor boxes with the same positions in a single-shot multi-box detector model, like YOLO? In particular, I notice Google's BlazeFace model does this. If the ...
1
vote
0answers
34 views

Why Anchor Boxes in Object Detection

What I understand from the anchor boxes is that they are predefined set of boxes of different sizes and shapes. A model like YOLO predicts offsets of the coordinates for each anchor box along with ...
3
votes
1answer
904 views

1 neuron BCE loss VS 2 neurons CE loss

I built a custom version of YOLO that should only detect one type of objects, where the objectness measure (which tells how likely a bounding-box contains an object of any type), is learned using a ...
1
vote
0answers
67 views

yolo v1: how gradients in grids with no objects overpower

I am reading yolo v1 paper. I am having confusion while trying to understand this: "Also, in every image many grid cells do not contain any object. This pushes the “confidence” scores of those ...
0
votes
1answer
154 views

yolo v1: why we weigh localization error more than classification error

I'm reading yolo v1 paper. I am trying to understand this part of the paper: "We use sum-squared error because it is easy to optimize, however it does not perfectly align with our goal of ...
0
votes
0answers
29 views

Yolo for object detection

I am working on (RSNA Pneumonia Detection Challenge) of kaggle. In which we have to find if a patient is suffering from pneumonia and if suffering then find the abnormality in the image by finding ...
0
votes
1answer
68 views

In the case of YOLO, how does the network assign a box in it's grid based on the midpoint of the object?

My question is that how in YOLO, the networks does the midpoint of grid cell think ? I'm not completely sure I understand it. How can we know the midpoint of any object before actually knowing where ...
1
vote
0answers
15 views

Best way for robust hand tracking on PI 4

I need a robust hand tracking which should be running on a Raspberry Pi 4 model. Does anyone have some experience with that? One way could be to use OpenCV but I think it's just using the skin color ...
2
votes
0answers
974 views

Yolov3: Single-class vs multiple class

I'm really new to object detection with Yolov3. Let's say I have 10 classes and the amount of data is approximately the same. Do I achieve better average precision when I use 10 Yolo models and train ...
2
votes
1answer
46 views

Performance of MaskRCNN/YOLO as a function of object size in pixels

I am trying to find references on how the resolution of an object affects the ability of object detection systems such as MaskRCNN and YOLO to correctly identify the object. For example, if the ...
1
vote
1answer
195 views

How exactly the midpoint of the object is selected in YOLO algorithm?

The boundaries of the object are encoded into 4 scalars: Bx, By, Bh, Bw. Bh and Bw are calculated using the ratio of the width of the bounding box to the width of the relative grid cell. But I can't ...
3
votes
2answers
4k views

How are YOLO anchor boxes generated?

I am recently trying out darkflow, a Tensorflow implementation of Darknet written by Joseph Redmon. Looking at the configuration files, I noticed a section called region as shown below. ...
1
vote
0answers
436 views

The reason for multiple bounding boxes use for each grid cell - YOLO

I'm not quite sure what is the main reason why YOLO uses multiple bounding boxes for a grid cell. An answer I can find on web is for multiple aspect ratio in the prediction. However I don’t think it’s ...
5
votes
2answers
749 views

What is sigma function in the YOLO object detector?

I have gone through the YOLO9000 paper, in that they have mentioned that network predicts 5 coordinates of the bounding box, and from that we find the exact centre coordinates and the width and height....
0
votes
1answer
338 views

Combining custom YOLO network for face detection with another CNN

I am looking for a way to build and train an end-to-end CNN that contains two steps: 1) a CNN for finding a face and hands in the image and 2) CNN that works on the crops of the face and hands. To ...
0
votes
0answers
155 views

How to “use” Yolo Loss Function

I am dealing with Yolo Loss Function (the following). $$\begin{align} &\lambda_{coord} \sum_{i=0}^{S^2}\sum_{j=0}^B \mathbb{1}_{ij}^{obj}[(x_i-\hat{x}_i)^2 + (y_i-\hat{y}_i)^2 ] \\&+ \lambda_{...
2
votes
1answer
3k views

YOLOv3 loss function

Follow-up to stats.stackexchange.com/questions/373266/yolo-v3-loss-function: In trying to finalize the development of my training labels and loss function I'm confused by the part in bold in the ...
0
votes
1answer
1k views

what purpose do the grid cells serve in YOLO object detection algorithm?

so I was looking at YOLO and I read several blogs online, but one concept I'm having trouble understanding is why do we want to divide the image into different grids, and then predict the bounding box ...
1
vote
0answers
361 views

Is YOLO a good algorithm for defect detection on images?

I wish to train an algorithm to detect defects on images of labels. These may be such things as scratches, tears and voids. I would like to try to train a YOLO algorithm to do this, but it is very ...
8
votes
1answer
13k views

Yolo v3 loss function

The original loss function can be seen here and is more or less explained in Yolo Loss function explanation: \begin{align} &\lambda_{coord} \sum_{i=0}^{S^2}\sum_{j=0}^B \mathbb{1}_{ij}^{obj}[(x_i-...
7
votes
1answer
2k views

On Yolo, and its loss function

I'm having a hard time understanding some on the inner-working of YOLO, especially the loss function depicted in this seminal paper. Bear in mind that I'm nowhere closed to being a specialist in deep ...
3
votes
0answers
1k views

What is the need of multiple Bounding Boxes per grid cell in YOLO v1?

This question is regarding YOLO v1 architecture as in here. I am confused as to why authors have used 2 bounding boxes per grid cell for training. Assuming there can be only one object per grid cell. ...
2
votes
1answer
907 views

Understanding the YOLO algorithm

I am trying to understand the logic behind object detection and the YOLO algorithm. I have read numerous blogs, tutorials, videos, papers, yet I am still not sure if I understood it correctly. Let's ...
3
votes
1answer
1k views

YOLO loss function width and height component explanation

I am reading this paper on how yolo defines loss function. https://arxiv.org/abs/1506.02640 I did research on other posts, but these posts did not seem to answer my confusion: (How to calculate the ...
2
votes
1answer
996 views

yolo cost function

At the output of the final layer of yolo, a leaky-relu is applied to the output, so if we have negative values for the width and height, the cost function will return a null value since we would have ...
1
vote
1answer
2k views

object detection loss function YOLO

as we know , in detection we have 2 loss : one is localization loss other is classification loss , in the formulation the 1th , 2th term related to localization loss and 3th term is related to ...
4
votes
1answer
893 views

Yolo loss function for detecting 1 class

I'm trying to work on a Yolo implementation which searches a 19x19 grid to find a specific item. There is only a single class in all of these images I am looking to get bounding boxes for. I'm a ...
2
votes
2answers
3k views

How does the YOLO network create boundaries for object detection?

I'm not sure I understood how the YOLO network works. If you look at the description, https://pjreddie.com/darknet/yolo/, it appears to me that all is done thanks to convolution only. You end up with ...
4
votes
2answers
2k views

Adjusting Grid Size in YOLO?

I was going through the YOLO Object Detection Paper by Joseph Redmon. The authors use a grid size of $S = 7$. If I am not wrong, the network architecture has carefully been curated for this specific ...
1
vote
3answers
3k views

You Only Look Once (YOLO): Convolutional Neural Network

This question refers to the YOLO architecture (figure 3). In their architecture they define a convolutional layer 7x7x64-s-2 followed by a maxpool layer ...
28
votes
5answers
44k views

Yolo Loss function explanation

I am trying to understand the Yolo v2 loss function: \begin{align} &\lambda_{coord} \sum_{i=0}^{S^2}\sum_{j=0}^B \mathbb{1}_{ij}^{obj}[(x_i-\hat{x}_i)^2 + (y_i-\hat{y}_i)^2 ] \\&+ \lambda_{...
1
vote
1answer
2k views

How to calculate the class probability of a grid cell in YOLO object detection algorithm?

I am going through the YOLO paper by Redmon, Divvala, Girshick & Farhadi (2015), "You Only Look Once: Unified, Real-Time Object Detection" (arXiV page here ) On the fourth page it mentions the ...