spmallick / learnopencv

Learn OpenCV : C++ and Python Examples

LearnOpenCV

This repository contains code for Computer Vision, Deep learning, and AI research articles shared on our blog LearnOpenCV.com.

Want to become an expert in AI? AI Courses by OpenCV is a great place to start.

List of Blog Posts

Blog Post	Code
YOLOv9 Instance Segmentation on Medical Dataset	Code
A Comprehensive Guide to Robotics
Integrating Gradio with OpenCV DNN	Code
Fine-Tuning YOLOv9 on Custom Dataset	Code
Dreambooth using Diffusers	Code
Introduction to Hugging Face Diffusers	Code
Introduction to Ultralytics Explorer API	Code
YOLOv9: Advancing the YOLO Legacy	Code
Fine-Tuning LLMs using PEFT	Code
Depth Anything: Accelerating Monocular Depth Perception	Code
Deciphering LLMs: From Transformers to Quantization	Code
YOLO Loss Function Part 2: GFL and VFL Loss	Code
YOLOv8-Object-Tracking-and-Counting-with-OpenCV	Code
Stereo Vision in ADAS: Pioneering Depth Perception Beyond LiDAR	Code
YOLO Loss Function Part 1: SIoU and Focal Loss	Code
Moving Object Detection with OpenCV	Code
Integrating ADAS with Keypoint Feature Pyramid Network for 3D LiDAR Object Detection	Code
Mastering All YOLO Models from YOLOv1 to YOLO-NAS: Papers Explained (2024)
GradCAM: Enhancing Neural Network Interpretability in the Realm of Explainable AI	Code
Text Summarization using T5: Fine-Tuning and Building Gradio App	Code
3D LiDAR Visualization using Open3D: A Case Study on 2D KITTI Depth Frames for Autonomous Driving	Code
Fine Tuning T5: Text2Text Transfer Transformer for Building a Stack Overflow Tag Generator	Code
SegFormer 🤗 : Fine-Tuning for Improved Lane Detection in Autonomous Vehicles	Code
Fine-Tuning BERT using Hugging Face Transformers	Code
YOLO-NAS Pose	Code
BERT: Bidirectional Encoder Representations from Transformers	Code
Comparing KerasCV YOLOv8 Models on the Global Wheat Data 2020	Code
Top 5 AI papers of September 2023
Empowering Drivers: The Rise and Role of Advanced Driver Assistance Systems
Semantic Segmentation using KerasCV DeepLabv3+	Code
Object Detection using KerasCV YOLOv8	Code
Fine-tuning YOLOv8 Pose Models for Animal Pose Estimation	Code
Top 5 AI papers of August 2023
Fine Tuning TrOCR - Training TrOCR to Recognize Curved Text	Code
TrOCR - Getting Started with Transformer Based OCR	Code
Facial Emotion Recognition	Code
Object Keypoint Similarity in Keypoint Detection	Code
Real Time Deep SORT with Torchvision Detectors	Code
Top 5 AI papers of July 2023
Medical Image Segmentation	Code
Weighted Boxes Fusion in Object Detection: A Comparison with Non-Maximum Suppression	Code
Medical Multi-label Classification with PyTorch & Lightning	Code
Getting Started with PaddlePaddle: Exploring Object Detection, Segmentation, and Keypoints	Code
Drone Programming With Computer Vision A Beginners Guide	Code
How to Build a Pip Installable Package & Upload to PyPi
IoU Loss Functions for Faster & More Accurate Object Detection
Exploring Slicing Aided Hyper Inference for Small Object Detection	Code
Advancements in Face Recognition Models, Toolkit and Datasets
Train YOLO NAS on Custom Dataset	Code
Train YOLOv8 Instance Segmentation on Custom Data	Code
YOLO-NAS: New Object Detection Model Beats YOLOv6 & YOLOv8	Code
Segment Anything – A Foundation Model for Image Segmentation	Code
Build a Video to Slides Converter Application using the Power of Background Estimation and Frame Differencing in OpenCV	Code
A Closer Look at CVAT: Perfecting Your Annotations	YouTube
ControlNet - Achieving Superior Image Generation Results	Code
InstructPix2Pix - Edit Images With Prompts	Code
NVIDIA Spring GTC 2023 Day 4: Ending on a High Note with Top Moments from the Finale!
NVIDIA Spring GTC 2023 Day 3: Digging deeper into Deep Learning, Semiconductors & more!
NVIDIA Spring GTC 2023 Day 2: Jensen’s keynote & the iPhone moment of AI is here!
NVIDIA Spring GTC 2023 Day 1: Welcome to the future!
NVIDIA GTC Spring 2023 Curtain Raiser
Stable Diffusion - A New Paradigm in Generative AI	Code
OpenCV Face Recognition – Does Face Recognition Work on AI-Generated Images?
An In-Depth Guide to Denoising Diffusion Probabilistic Models – From Theory to Implementation	Code
From Pixels to Paintings: The Rise of Midjourney AI Art
Mastering DALL·E 2: A Breakthrough in AI Art Generation
Top 10 AI Art Generation Tools using Diffusion Models
The Future of Image Recognition is Here: PyTorch Vision Transformer	Code
Understanding Attention Mechanism in Transformer Neural Networks	Code
Deploying a Deep Learning Model using Hugging Face Spaces and Gradio	Code
Train YOLOv8 on Custom Dataset – A Complete Tutorial	Code
Introduction to Diffusion Models for Image Generation	Code
Building An Automated Image Annotation Tool: PyOpenAnnotate	Code
Ultralytics YOLOv8: State-of-the-Art YOLO Models	Code
Getting Started with YOLOv5 Instance Segmentation	Code
The Ultimate Guide To DeepLabv3 - With PyTorch Inference	Code
AI Fitness Trainer using MediaPipe: Squats Analysis	Code
YoloR - Paper Explanation & Inference -An In-Depth Analysis	Code
Roadmap To an Automated Image Annotation Tool Using Python	Code
Performance Comparison of YOLO Object Detection Models – An Intensive Study
FCOS - Anchor Free Object Detection Explained	Code
YOLOv6 Custom Dataset Training – Underwater Trash Detection	Code
What is EXIF Data in Images?	Code
t-SNE: T-Distributed Stochastic Neighbor Embedding Explained	Code
CenterNet: Objects as Points – Anchor-free Object Detection Explained	Code
YOLOv7 Pose vs MediaPipe in Human Pose Estimation	Code
YOLOv6 Object Detection – Paper Explanation and Inference	Code
YOLOX Object Detector Paper Explanation and Custom Training	Code
Driver Drowsiness Detection Using Mediapipe In Python	Code
GTC 2022 Big Bang AI announcements: Everything you need to know
NVIDIA GTC 2022 : The most important AI event this Fall
Object Tracking and Reidentification with FairMOT	Code
What is Face Detection? – The Ultimate Guide for 2022	Code
Document Scanner: Custom Semantic Segmentation using PyTorch-DeepLabV3	Code
Fine Tuning YOLOv7 on Custom Dataset	Code
Center Stage for Zoom Calls using MediaPipe	Code
Mean Average Precision (mAP) in Object Detection
YOLOv7 Object Detection Paper Explanation and Inference	Code
Pothole Detection using YOLOv4 and Darknet	Code
Automatic Document Scanner using OpenCV	Code
Demystifying GPU architectures for deep learning: Part 2	Code
Demystifying GPU Architectures For Deep Learning	Code
Intersection-over-Union(IoU)-in-Object-Detection-and-Segmentation	Code
Understanding Multiple Object Tracking using DeepSORT	Code
Optical Character Recognition using PaddleOCR	Code
Gesture Control in Zoom Call using Mediapipe	Code
A Deep Dive into Tensorflow Model Optimization	Code
DepthAI Pipeline Overview: Creating a Complex Pipeline	Code
TensorFlow Lite Model Maker: Create Models for On-Device Machine Learning	Code
TensorFlow Lite: Model Optimization for On Device Machine Learning	Code
Object detection with depth measurement using pre-trained models with OAK-D	Code
Custom Object Detection Training using YOLOv5	Code
Object Detection using Yolov5 and OpenCV DNN (C++/Python)	Code
Create Snapchat/Instagram filters using Mediapipe	Code
AUTOSAR C++ compliant deep learning inference with TensorRT	Code
NVIDIA GTC 2022 Day 4 Highlights: Meet the new Jetson Orin
NVIDIA GTC 2022 Day 3 Highlights: Deep Dive into Hopper architecture
NVIDIA GTC 2022 Day 2 Highlights: Jensen’s Keynote
NVIDIA GTC 2022 Day 1 Highlights: Brilliant Start
Automatic License Plate Recognition using Python	Code
Building a Poor Body Posture Detection and Alert System using MediaPipe	Code
Introduction to MediaPipe	Code
Disparity Estimation using Deep Learning	Code
How to build Chrome Dino game bot using OpenCV Feature Matching	Code
Top 10 Sources to Find Computer Vision and AI Models
Multi-Attribute and Graph-based Object Detection
Plastic Waste Detection with Deep Learning	Code
Ensemble Deep Learning-based Defect Classification and Detection in SEM Images
Building Industrial embedded deep learning inference pipelines with TensorRT	Code
Transfer Learning for Medical Images
Stereo Vision and Depth Estimation using OpenCV AI Kit	Code
Introduction to OpenCV AI Kit and DepthAI	Code
WeChat QR Code Scanner in OpenCV	Code
AI behind the Diwali 2021 ‘Not just a Cadbury ad’
Model Selection and Benchmarking with Modelplace.AI	Model Zoo
Real-time style transfer in a zoom meeting	Code
Introduction to OpenVino Deep Learning Workbench	Code
Running OpenVino Models on Intel Integrated GPU	Code
Post Training Quantization with OpenVino Toolkit	Code
Introduction to Intel OpenVINO Toolkit
Human Action Recognition using Detectron2 and LSTM	Code
Pix2Pix:Image-to-Image Translation in PyTorch & TensorFlow	Code
Conditional GAN (cGAN) in PyTorch and TensorFlow	Code
Deep Convolutional GAN in PyTorch and TensorFlow	Code
Introduction to Generative Adversarial Networks (GANs)	Code
Human Pose Estimation using Keypoint RCNN in PyTorch	Code
Non Maximum Suppression: Theory and Implementation in PyTorch	Code
MRNet – The Multi-Task Approach	Code
Generative and Discriminative Models
Playing Chrome's T-Rex Game with Facial Gestures	Code
Variational Autoencoder in TensorFlow	Code
Autoencoder in TensorFlow 2: Beginner’s Guide	Code
Deep Learning with OpenCV DNN Module: A Definitive Guide	Code
Depth perception using stereo camera (Python/C++)	Code
Contour Detection using OpenCV (Python/C++)	Code
Super Resolution in OpenCV	Code
Improving Illumination in Night Time Images	Code
Video Classification and Human Activity Recognition	Code
How to use OpenCV DNN Module with Nvidia GPU on Windows	Code
How to use OpenCV DNN Module with NVIDIA GPUs	Code
Code OpenCV in Visual Studio
Install OpenCV on Windows – C++ / Python	Code
Face Recognition with ArcFace	Code
Background Subtraction with OpenCV and BGS Libraries	Code
RAFT: Optical Flow estimation using Deep Learning	Code
Making A Low-Cost Stereo Camera Using OpenCV	Code
Optical Flow in OpenCV (C++/Python)	Code
Introduction to Epipolar Geometry and Stereo Vision	Code
Classification With Localization: Convert any keras Classifier to a Detector	Code
Photoshop Filters in OpenCV	Code
Tetris Game using OpenCV Python	Code
Image Classification with OpenCV for Android	Code
Image Classification with OpenCV Java	Code
PyTorch to Tensorflow Model Conversion	Code
Snake Game with OpenCV Python	Code
Stanford MRNet Challenge: Classifying Knee MRIs	Code
Experiment Logging with TensorBoard and wandb	Code
Understanding Lens Distortion	Code
Image Matting with state-of-the-art Method “F, B, Alpha Matting”	Code
Bag Of Tricks For Image Classification - Let's check if it is working or not	Code
Getting Started with OpenCV CUDA Module	Code
Training a Custom Object Detector with DLIB & Making Gesture Controlled Applications	Code
How To Run Inference Using TensorRT C++ API	Code
Using Facial Landmarks for Overlaying Faces with Medical Masks	Code
Tensorboard with PyTorch Lightning	Code
Otsu's Thresholding with OpenCV	Code
PyTorch-to-CoreML-model-conversion	Code
Playing Rock, Paper, Scissors with AI	Code
CNN Receptive Field Computation Using Backprop with TensorFlow	Code
CNN Fully Convolutional Image Classification with TensorFlow	Code
How to convert a model from PyTorch to TensorRT and speed up inference	Code
Efficient image loading	Code
Graph Convolutional Networks: Model Relations In Data	Code
Getting Started with Federated Learning with PyTorch and PySyft	Code
Creating a Virtual Pen & Eraser	Code
Getting Started with PyTorch Lightning	Code
Multi-Label Image Classification with PyTorch: Image Tagging	Code
Funny Mirrors Using OpenCV	code
t-SNE for ResNet feature visualization	Code
Multi-Label Image Classification with Pytorch	Code
CNN Receptive Field Computation Using Backprop	Code
CNN Receptive Field Computation Using Backprop with TensorFlow	Code
Augmented Reality using AruCo Markers in OpenCV(C++ and Python)	Code
Fully Convolutional Image Classification on Arbitrary Sized Image	Code
Camera Calibration using OpenCV	Code
Geometry of Image Formation
Ensuring Training Reproducibility in Pytorch
Gaze Tracking
Simple Background Estimation in Videos Using OpenCV	Code
Applications of Foreground-Background separation with Semantic Segmentation	Code
EfficientNet: Theory + Code	Code
PyTorch for Beginners: Mask R-CNN Instance Segmentation with PyTorch	Code
PyTorch for Beginners: Faster R-CNN Object Detection with PyTorch	Code
PyTorch for Beginners: Semantic Segmentation using torchvision	Code
PyTorch for Beginners: Comparison of pre-trained models for Image Classification	Code
PyTorch for Beginners: Basics	Code
PyTorch Model Inference using ONNX and Caffe2	Code
Image Classification Using Transfer Learning in PyTorch	Code
Hangman: Creating games in OpenCV	Code
Image Inpainting with OpenCV (C++/Python)	Code
Hough Transform with OpenCV (C++/Python)	Code
Xeus-Cling: Run C++ code in Jupyter Notebook	Code
Gender & Age Classification using OpenCV Deep Learning ( C++/Python )	Code
Invisibility Cloak using Color Detection and Segmentation with OpenCV	Code
Fast Image Downloader for Open Images V4 (Python)	Code
Deep Learning based Text Detection Using OpenCV (C++/Python)	Code
Video Stabilization Using Point Feature Matching in OpenCV	Code
Training YOLOv3 : Deep Learning based Custom Object Detector	Code
Using OpenVINO with OpenCV	Code
Duplicate Search on Quora Dataset	Code
Shape Matching using Hu Moments (C++/Python)	Code
Install OpenCV 4 on CentOS (C++ and Python)	Code
Install OpenCV 3.4.4 on CentOS (C++ and Python)	Code
Install OpenCV 3.4.4 on Red Hat (C++ and Python)	Code
Install OpenCV 4 on Red Hat (C++ and Python)	Code
Install OpenCV 4 on macOS (C++ and Python)	Code
Install OpenCV 3.4.4 on Raspberry Pi	Code
Install OpenCV 3.4.4 on macOS (C++ and Python)	Code
OpenCV QR Code Scanner (C++ and Python)	Code
Install OpenCV 3.4.4 on Windows (C++ and Python)	Code
Install OpenCV 3.4.4 on Ubuntu 16.04 (C++ and Python)	Code
Install OpenCV 3.4.4 on Ubuntu 18.04 (C++ and Python)	Code
Universal Sentence Encoder	Code
Install OpenCV 4 on Raspberry Pi	Code
Install OpenCV 4 on Windows (C++ and Python)	Code
Face Detection – Dlib, OpenCV, and Deep Learning ( C++ / Python )	Code
Hand Keypoint Detection using Deep Learning and OpenCV	Code
Deep learning based Object Detection and Instance Segmentation using Mask R-CNN in OpenCV (Python / C++)	Code
Install OpenCV 4 on Ubuntu 18.04 (C++ and Python)	Code
Install OpenCV 4 on Ubuntu 16.04 (C++ and Python)	Code
Multi-Person Pose Estimation in OpenCV using OpenPose	Code
Heatmap for Logo Detection using OpenCV (Python)	Code
Deep Learning based Object Detection using YOLOv3 with OpenCV ( Python / C++ )	Code
Convex Hull using OpenCV in Python and C++	Code
MultiTracker : Multiple Object Tracking using OpenCV (C++/Python)	Code
Convolutional Neural Network based Image Colorization using OpenCV	Code
SVM using scikit-learn	Code
GOTURN: Deep Learning based Object Tracking	Code
Find the Center of a Blob (Centroid) using OpenCV (C++/Python)	Code
Support Vector Machines (SVM)	Code
Batch Normalization in Deep Networks	Code
Deep Learning based Character Classification using Synthetic Dataset	Code
Image Quality Assessment : BRISQUE	Code
Understanding AlexNet
Deep Learning based Text Recognition (OCR) using Tesseract and OpenCV	Code
Deep Learning based Human Pose Estimation using OpenCV ( C++ / Python )	Code
Number of Parameters and Tensor Sizes in a Convolutional Neural Network (CNN)
How to convert your OpenCV C++ code into a Python module	Code
CV4Faces : Best Project Award 2018
Facemark : Facial Landmark Detection using OpenCV	Code
Image Alignment (Feature Based) using OpenCV (C++/Python)	Code
Barcode and QR code Scanner using ZBar and OpenCV	Code
Keras Tutorial : Fine-tuning using pre-trained models	Code
OpenCV Transparent API
Face Reconstruction using EigenFaces (C++/Python)	Code
Eigenface using OpenCV (C++/Python)	Code
Principal Component Analysis
Keras Tutorial : Transfer Learning using pre-trained models	Code
Keras Tutorial : Using pre-trained Imagenet models	Code
Technical Aspects of a Digital SLR
Using Harry Potter interactive wand with OpenCV to create magic
Install OpenCV 3 and Dlib on Windows ( Python only )
Image Classification using Convolutional Neural Networks in Keras	Code
Understanding Autoencoders using Tensorflow (Python)	Code
Best Project Award : Computer Vision for Faces
Understanding Activation Functions in Deep Learning
Image Classification using Feedforward Neural Network in Keras	Code
Exposure Fusion using OpenCV (C++/Python)	Code
Understanding Feedforward Neural Networks
High Dynamic Range (HDR) Imaging using OpenCV (C++/Python)	Code
Deep learning using Keras – The Basics	Code
Selective Search for Object Detection (C++ / Python)	Code
Installing Deep Learning Frameworks on Ubuntu with CUDA support
Parallel Pixel Access in OpenCV using forEach	Code
cvui: A GUI lib built on top of OpenCV drawing primitives	Code
Install Dlib on Windows
Install Dlib on Ubuntu
Install OpenCV3 on Ubuntu
Read, Write and Display a video using OpenCV ( C++/ Python )	Code
Install Dlib on MacOS
Install OpenCV 3 on MacOS
Install OpenCV 3 on Windows
Get OpenCV Build Information ( getBuildInformation )
Color spaces in OpenCV (C++ / Python)	Code
Neural Networks : A 30,000 Feet View for Beginners
Alpha Blending using OpenCV (C++ / Python)	Code
User stories : How readers of this blog are applying their knowledge to build applications
How to select a bounding box ( ROI ) in OpenCV (C++/Python) ?
Automatic Red Eye Remover using OpenCV (C++ / Python)	Code
Bias-Variance Tradeoff in Machine Learning
Embedded Computer Vision: Which device should you choose?
Object Tracking using OpenCV (C++/Python)	Code
Handwritten Digits Classification : An OpenCV ( C++ / Python ) Tutorial	Code
Training a better Haar and LBP cascade based Eye Detector using OpenCV
Deep Learning Book Gift Recipients
Minified OpenCV Haar and LBP Cascades	Code
Deep Learning Book Gift
Histogram of Oriented Gradients
Image Recognition and Object Detection : Part 1
Head Pose Estimation using OpenCV and Dlib	Code
Live CV : A Computer Vision Coding Application
Approximate Focal Length for Webcams and Cell Phone Cameras
Configuring Qt for OpenCV on OSX	Code
Rotation Matrix To Euler Angles	Code
Speeding up Dlib’s Facial Landmark Detector
Warp one triangle to another using OpenCV ( C++ / Python )	Code
Average Face : OpenCV ( C++ / Python ) Tutorial	Code
Face Swap using OpenCV ( C++ / Python )	Code
Face Morph Using OpenCV — C++ / Python	Code
Deep Learning Example using NVIDIA DIGITS 3 on EC2
NVIDIA DIGITS 3 on EC2
Homography Examples using OpenCV ( Python / C ++ )	Code
Filling holes in an image using OpenCV ( Python / C++ )	Code
How to find frame rate or frames per second (fps) in OpenCV ( Python / C++ ) ?	Code
Delaunay Triangulation and Voronoi Diagram using OpenCV ( C++ / Python)	Code
OpenCV (C++ vs Python) vs MATLAB for Computer Vision
Facial Landmark Detection
Why does OpenCV use BGR color format ?
Computer Vision for Predicting Facial Attractiveness	Code
applyColorMap for pseudocoloring in OpenCV ( C++ / Python )	Code
Image Alignment (ECC) in OpenCV ( C++ / Python )	Code
How to find OpenCV version in Python and C++ ?
Baidu banned from ILSVRC 2015
OpenCV Transparent API
How Computer Vision Solved the Greatest Soccer Mystery of All Time
Embedded Vision Summit 2015
Read an Image in OpenCV ( Python, C++ )	Code
Non-Photorealistic Rendering using OpenCV ( Python, C++ )	Code
Seamless Cloning using OpenCV ( Python , C++ )	Code
OpenCV Threshold ( Python , C++ )	Code
Blob Detection Using OpenCV ( Python, C++ )	Code
Turn your OpenCV Code into a Web API in under 10 minutes — Part 1
How to compile OpenCV sample Code ?
Install OpenCV 3 on Yosemite ( OSX 10.10.x )

learnopencv's Issues

OpenCV Version ???

In which version of OpenCV are we suppose to run the examples ?

failed to load video

SystemExit Traceback (most recent call last)
in ()
53 if not success:
54 print('Failed to read video')
---> 55 sys.exit(1)
56
57 ## Select boxes

SystemExit: 1

Colorization/colorizeImage.cpp

line 114 should be
imwrite(str, color);
and not
imwrite(str, color*255);

Thanks.

extension confusion

Homography/homography.py is not python code

Pedestrian counter with two of lines

Hi,

I'm interested on Pedestrian Counter project with openCV. One of the sample source code that i've found is shared by @anandsinghkunwar on git hub https://github.com/anandsinghkunwar/pedestrian-counter

But it quite confusing on returning of function line1(x,y) and line2(x,y). I want to change the default lines to be transverse over the frame to be like this:

    cv2.line(frame, (0,100), (500,100), (255, 0, 0), 2)
    cv2.line(frame, (0,200), (500,200), (255, 0, 0), 2)

Anybody can help me to tuning the function line1(x,y) and line2(x,y)

not working error at alignImages im1Gray = cv2.cvtColor(im1, cv2.COLOR_BGR2GRAY)

this error, happens

im1Gray = cv2.cvtColor(im1, cv2.COLOR_BGR2GRAY)

error: C:\ci\opencv_1512688052760\work\modules\imgproc\src\color.cpp:11048: error: (-215) scn == 3 || scn == 4 in function cv::cvtColor

any soluation ?

Can't find output blob "image" in function addInput

can someone let me know?

tracking by detecting

this blog(for Chinese engineers) shows how to track by detecting with yolo https://www.cnblogs.com/xiaozhi_5638/p/9376784.html

How to Convert your OpenCV C++ code Into a Python Module

It is really cool work.
I want to know how to complete it in Windows. Is that feasible？
thanks.

missing buildOpticalFlowPyramid for TrackerMedianFlow in deployed OSX app

solved

copy/paste typo in learnopencv/ObjectDetection-YOLO/README

"Commandline usage to colorize"
The colorize should be remove

Advantage to CNN?

What's the advantage of Selective Search to CNN?

YOLO detection false negative

Hello.
I launched yolo detection with video stream(IP-camera).
Picture:

There's two cars, but algorithm detected only one.
Can I tune program to fix it? Help me plz

iteration through a folder.

I am trying Object deection with yolo.
can you you write a script so that i can iterate through a folder with images at a time

what is the dimensions of 3D model?

In the headpose.py file, what means 3D model points ? How to calc it?

3D model points.

model_points = np.array([
(0.0, 0.0, 0.0), # Nose tip
(0.0, -330.0, -65.0), # Chin
(-225.0, 170.0, -135.0), # Left eye left corner
(225.0, 170.0, -135.0), # Right eye right corne
(-150.0, -150.0, -125.0), # Left Mouth corner
(150.0, -150.0, -125.0) # Right mouth corner

                    ])

Gait Analysis

One can also use open pose estimation for gait analysis. Gait energy image is also a good technique.

opencv has no module dnn

Can someone help it out?

Undefined reference to cv::Subdiv2D::getTriangleList - faceAverage.cpp

Hi, i'm developing an android application about Average Face.

I have a cpp file based on faceAverage.cpp (https://github.com/spmallick/learnopencv/blob/master/FaceAverage/faceAverage.cpp)
but when i compile the code, i get this error:
Error:(154) undefined reference to 'cv::Subdiv2D::getTriangleList(std::__ndk1::vector<cv::Vec<float, 6>, std::__ndk1::allocator<cv::Vec<float, 6> > >&) const'

The error occur inside the calculateDelaunayTriangles function, precisely at this statement: subdiv.getTriangleList(triangleList)

The calculateDelaunayTriangles function is exactly the same as in faceAverage.cpp

How can i fix the error?

can you write an tutorials to train dataset for YOLO v3 ?

OpenCV Error: Iterations do not converge (The algorithm stopped before its convergence. The correlation is going to be minimized. Images may be uncorrelated or non-overlapped) in cv::findTransformECC, file C:\build\master_winpack-build-win64-vc14\opencv\modules\video\src\ecc.cpp, line 540

When I use the code you supply in image alignment, I uploaded two .png file, sometimes it can run correctly, but sometimes it won't and shows the title error. Could you help me to figure it out?
Thank you!

can i share your code in my repository

please look at https://github.com/sturkmen72/opencv_samples/blob/master/select-region-on-mouse-click.cpp. can i put some codes from http://opencvexamples.blogspot.com/ in my repository

Incorrect output when using morph

Thanks for that nice example.
I want to use your code with automatically found landmarks (using dlib's landmark detector). So how can I get the correct assignment of the rectangles generated with delauny triangulation? Because it seems that when I just take the given order it is not correct. Means the result does not look like a face (but like rectangles on a face). Hope you can understand what I mean. Here's some pseudo code of what I'm doing:

• get landmarks on face 1using dlib
• get landmarks on face 2 using dlib
• delauny triangulation on both
• pixel correspondence of morphed image (use rectangles from face 2)
• for(rectangles from face 1) {
• get affine transformation(rectangleFace1, rectangleFace2)
• warp triangles
• }
  By the way I want to completely override the rectangles from the first image with the rectangles from the second image. So a kind of simply transforming the rectangles from second image (in the form of the first image).

Please help, thanks in advance.
Best regards
Patricia

Can you share the source of object-tracking combined with detecting using SIFT algorithm?

As you see, the source tracking runs at the situation that initiated the bounding box manually.Sometimes it's not useful.So ,can you track the object combined with detecting using SIFT algorithm so that the bounding box can be initiated automatically.Or maybe you can guide me to realize the code?I hope to hear you as soon as possible.Thank you.

about draw matches

What is the mapIdx for hand model?

Hello
I would like to extract hand keypoints in the images. So, In the multi-person-openpose.py file, how can I define the value for mapIdx of hand?
Please help me.

wrong fps in tracker.cpp

Tracker.cpp gives fps values only for the tracker->update, not for video.read() + tracker->update.

Better start with timer = (double)getTickCount(); just before the while(video.read) loop, and again at the end of that loop. Remove the timer from the first line in the loop.
This gives reasonable fps.

OpenCV Error: Assertion failed (output_slice.isContinuous() && output_slice.size== curr_output.size) in cv::dnn::experimental_dnn_v3::Net::Impl::fuseLayers,

the error With file C:\build\master_winpack-build-win64-vc14\opencv\modules\dnn\src\dnn.cpp, line1430

there is no problem with python file when i run it,but the c++ file shows the title error when i run it in vs2015 and opencv 3.4.Could you help me to figure it out?
Very Thank you!

advice for face morph

Hello! Thanks for this amazing repo, so much to learn!!
I am writing a program based on the facemorph code. It works really nicely except one detail that I can't solve yet, but I feel it must be something really simple. The warped triangles seem to overlap by 1 pixel, and their pixel colour then wraps around 255 (as I assume) and I get these lines in between the pieces (view attached image).
Any idea what would be a simple solution to that? Greatly appreciate you help!
Thanks

ConvexHull Error compiling..

xample.cpp: In function ‘int main(int, char**)’:
example.cpp:48:22: error: ‘>>’ should be ‘> >’ within a nested template argument list
   vector<vector<Point>> hull(contours.size());

the source code should have a space between the >> or it assumes bit shift..

i.e. vector< vector<Point> > hull(contours.size());

how do i detect only one class ?

I want to detect only one class(person) in my image. like, I want to count the number of persons in my image. how should i proceed.

detecting a single class.

I want to detect only one class person . I want to count the number of person detected.
It would be a great help.

how to Real-time calculation of image size？

how to Real-time calculation of image size？

Such as the actual size of a car in the video

Take a photo to calculate the height of a person's height or a chair in the photo

How to generate the facial landmark text file?

I see you have used txt files for image facial coordianates. How did you generate those? I am not able to iterate over the predictor function of the dlib? Can you please share the code snippet?

YOLO object detection get models.sh command not found

./getModels.sh: line 1: wget: command not found
./getModels.sh: line 2: wget: command not found
./getModels.sh: line 3: wget: command not found

KerasMLP-MNIST - SSH error when downloading MNIST with KERAS

Environnement :
-MAC OSX
-PyCharm Community Edition 2017.2
-Python 3.6

Code raising the error in keras-mlp-mnist.ipynb :
from keras.datasets import mnist

Error raised :
ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)

Complete log :

Using TensorFlow backend.
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/importlib/_bootstrap.py:219: RuntimeWarning: compiletime version 3.5 of module 'tensorflow.python.framework.fast_tensor_util' does not match runtime version 3.6
return f(*args, **kwds)
2017-11-06 18:20:25.647592: I tensorflow/core/platform/cpu_feature_guard.cc:137] Your CPU supports instructions that this TensorFlow binary was not compiled to use: SSE4.1 SSE4.2 AVX AVX2 FMA
Downloading data from https://s3.amazonaws.com/img-datasets/mnist.npz
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py", line 1318, in do_open
encode_chunked=req.has_header('Transfer-encoding'))
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py", line 1239, in request
self._send_request(method, url, body, headers, encode_chunked)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py", line 1285, in _send_request
self.endheaders(body, encode_chunked=encode_chunked)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py", line 1234, in endheaders
self._send_output(message_body, encode_chunked=encode_chunked)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py", line 1026, in _send_output
self.send(msg)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py", line 964, in send
self.connect()
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/http/client.py", line 1400, in connect
server_hostname=server_hostname)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/ssl.py", line 407, in wrap_socket
_context=self, _session=session)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/ssl.py", line 814, in init
self.do_handshake()
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/ssl.py", line 1068, in do_handshake
self._sslobj.do_handshake()
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/ssl.py", line 689, in do_handshake
self._sslobj.do_handshake()
ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/keras/utils/data_utils.py", line 220, in get_file
urlretrieve(origin, fpath, dl_progress)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py", line 248, in urlretrieve
with contextlib.closing(urlopen(url, data)) as fp:
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py", line 223, in urlopen
return opener.open(url, data, timeout)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py", line 526, in open
response = self._open(req, data)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py", line 544, in _open
'_open', req)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py", line 504, in _call_chain
result = func(*args)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py", line 1361, in https_open
context=self._context, check_hostname=self._check_hostname)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/urllib/request.py", line 1320, in do_open
raise URLError(err)
urllib.error.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)>

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/Users/damien/Documents/Dev/Python/keras-mlp-mnist/Code.py", line 27, in
(train_images, train_labels), (test_images, test_labels) = mnist.load_data()
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/keras/datasets/mnist.py", line 17, in load_data
file_hash='8a61469f7ea1b51cbae51d4f78837e45')
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/keras/utils/data_utils.py", line 222, in get_file
raise Exception(error_msg.format(origin, e.errno, e.reason))
Exception: URL fetch failure on https://s3.amazonaws.com/img-datasets/mnist.npz: None -- [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)

Process finished with exit code 1

.jpg.txt?

how did you convert the jpg files to a txt file, and why do you do so?

people counter

Hi sir am new to opencv i want the code for people counter (counting the people per hour,day,month)and stored in somewhere like database.

tracker-issue

I got a problem in the tracker example it could not find any of the trackers that implemented like (cv2.TrackerBoosting_create()) is it for the opencv version ?? i have installed 3.4.0.12 version

FaceAvereage - faces not morphing?

When I run python faceAverage.py I get this rather confused output.

Running the faceMorph.py does seem to work.

I'm running Python 2.7.6 on Ubuntu 14.04.4. Any idea what's going wrong?

Filled Circles

Wrt to the blob detector. Is there a possibility to draw the bounding circles as filled instead of the current state?

#include <opencv2/face.hpp>

Where is "#include <opencv2/face.hpp>"? Thank you

can be used ?

Hi, are these working modals?

Pb in the AlphaBlending code

Hello,

At this lines :
Mat alpha = Mat::zeros(foreGroundImage.size(), CV_8UC3);
merge(alphaChannels, alpha);

The code crashed on merge. The alpha Mat is not created.

Could you help ?
thx

Getting error while running reconstructFace.py

Reading model file pcaParams.yml
Traceback (most recent call last):
File "/home/vaibhav/PycharmProjects/reconstructFace.py", line 51, in
sz = (int(sz[0, 0]), int(sz[1, 0]), int(sz[2, 0]))
TypeError: 'NoneType' object has no attribute 'getitem'

Feature-based image metamorphosis

hei, thanks for your share,,,did you implement the paper 《Feature-based image metamorphosis》 in this project？

nothing happens when executing the code(Eigenface)

Hi there, I'm new in the field and have problem with getting result of executing Eigenface code, here is all i got when i run Eigenface.py
Reading images from F:\learnopencv-master\EigenFace\images...

I'm using winpython-3.4.2.2.amd64

Any idea will be helpful...! Thank you

extend interactiveColorDetect to get top color in image

https://github.com/spmallick/learnopencv/tree/master/ColorSpaces there is wonderful tutorial here.
can you extend the interactive color detect into that we feed a image and get the top 5 or all color
and corresponding max and min value in each color space

Getting build errors when building object detection example

I am trying to build the object detection example on a raspberry pi 3 running raspbian. My commandline is as follows.
g++ -ggdb pkg-config --cflags --libs /usr/local/lib/pkgconfig/opencv.pc obd.cpp -o obd.out
I am getting the following output.
^
obd.cpp:85:31: note: candidates are:
In file included from obd.cpp:5:0:
/usr/include/c++/4.8/fstream:467:7: note: std::basic_ifstream<_CharT, _Traits>::
basic_ifstream(const char*, std::ios_base::openmode) [with _CharT = char; _Trait
s = std::char_traits; std::ios_base::openmode = std::_Ios_Openmode]
basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in)
^
/usr/include/c++/4.8/fstream:467:7: note: no known conversion for argument 1 f
rom ‘std::string {aka std::basic_string}’ to ‘const char*’
/usr/include/c++/4.8/fstream:453:7: note: std::basic_ifstream<_CharT, _Traits>::
basic_ifstream() [with _CharT = char; _Traits = std::char_traits]
basic_ifstream() : __istream_type(), _M_filebuf()
^
/usr/include/c++/4.8/fstream:453:7: note: candidate expects 0 arguments, 1 pro
vided
/usr/include/c++/4.8/fstream:427:11: note: std::basic_ifstream::basic_ifst
ream(const std::basic_ifstream&)
class basic_ifstream : public basic_istream<_CharT, _Traits>
^
/usr/include/c++/4.8/fstream:427:11: note: no known conversion for argument 1
from ‘std::string {aka std::basic_string}’ to ‘const std::basic_ifstream&’

What do I need to do to fix this?

YOLO detection error

when I run object_detection_yolo.py, I got this error

user@user:~/Desktop/YOLOOpenCV$ python3 object_detection_yolo.py
OpenCV(3.4.1) Error: Parsing error (Unknown layer type: shortcut) in ReadDarknetFromCfgFile, file /io/opencv/modules/dnn/src/darknet/darknet_io.cpp, line 503
Traceback (most recent call last):
File "object_detection_yolo.py", line 33, in
net = cv.dnn.readNetFromDarknet(modelConfiguration, modelWeights)
cv2.error: OpenCV(3.4.1) /io/opencv/modules/dnn/src/darknet/darknet_io.cpp:503: error: (-212) Unknown layer type: shortcut in function ReadDarknetFromCfgFile

How can I solve this?

Compile error on ObjectDetection-YOLO

object_detection_yolo.cpp:40: undefined reference to cv::CommandLineParser::CommandLineParser(int, char const* const*, cv::String const&)'

ObjectDetection-YOLO

I think there's some Cmake options missed out when building opencv from source.

My compiler commands:

g++ -std=c++0x -ggdb `pkg-config --cflags --libs /usr/local/lib/pkgconfig/opencv.pc` object_detection_yolo.cpp -o object.out

Here's my opencv.pc details:

# Package Information for pkg-config

prefix=/usr/local
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
includedir_old=${prefix}/include/opencv
includedir_new=${prefix}/include

Name: OpenCV
Description: Open Source Computer Vision Library
Version: 3.4.2
Libs: -L${exec_prefix}/lib -lopencv_videostab -lopencv_stitching -lopencv_superres -lopencv_fuzzy -lopencv_hfs -lopencv_dnn_objdetect -lopencv_rgbd -lopencv_dpm -lopencv_optflow -lopencv_ximgproc -lopencv_ccalib -lopencv_structured_light -lopencv_xphoto -lopencv_saliency -lopencv_tracking -lopencv_datasets -lopencv_text -lopencv_dnn -lopencv_plot -lopencv_line_descriptor -lopencv_stereo -lopencv_img_hash -lopencv_xobjdetect -lopencv_surface_matching -lopencv_xfeatures2d -lopencv_shape -lopencv_ml -lopencv_phase_unwrapping -lopencv_bioinspired -lopencv_reg -lopencv_aruco -lopencv_face -lopencv_photo -lopencv_objdetect -lopencv_bgsegm -lopencv_calib3d -lopencv_features2d -lopencv_highgui -lopencv_videoio -lopencv_imgcodecs -lopencv_video -lopencv_flann -lopencv_freetype -lopencv_imgproc -lopencv_core
Libs.private: -ldl -lm -lpthread -lrt
Cflags: -I${includedir_old} -I${includedir_new}