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Extract Captcha Text using CNN in Python(Captcha solver)

Photo by Janik Fischer on Unsplash Captcha solver or captcha text extraction is a process of extracting text from the captcha image. This can be done by using OCR (Optical character recognition) tools like ‘Tesseract’. But to understand Computer vision more deeply you can build your own custom captcha solver. So let’s see how you can build your own captcha solver with the help of openCV and keras. Building Captcha Solver In order to detect the text in the captcha we will build a CNN model trained on separate image of letters of the captcha. For building the model we need to separate out each letter image from the captcha and write it for training the model. After training our model we can pass

Precision and Recall | Precision and Recall in machine learning

Precision and recall are the two terms which confused me a lot in my machine learning path. These terms sound easy but they are not as easy as they sound. And the high-level definition provided in most of the blogs are way out of my understanding, actually I never find those definitions easy to understand. So, I tried to find some other way to understand these terms with real world example. Photo by Karsten Winegeart on Unsplash Ok, enough of talking. Let’s start with where to use precision and recall instead of accuracy. So, take an example where you got an imbalanced data for skin cancer and you were asked to create a model to detect skin cancer. You created a model which detects skin cancer with very high accuracy say 98%. But, is it the perfect model? Or we

Understanding mean Average Precision for Object Detection (with Python Code)

Photo by  Avel Chuklanov  on  Unsplash If you ever worked on object detection problem where you need to predict the bounding box coordinates of the objects, you may have come across the term mAP (mean average precision). mAP is a metric used for evaluating object detectors. As the name suggest it is the average of the AP. To understand mAP , first we need to understand what is precision, recall and IoU(Intersection over union). Almost everyone is familiar with first two terms, in case you don’t know these terms I am here to help you. Precision and Recall Precision: It tells us how accurate is our predictions or proportion of data points that our model says relevant are actually relevant. Formula for precision Recall: It is ability of a model to find all the data points of inte

Dandruff - Causes and treatment

Hello readers, how are you? Today we will find out, how do you get rid of dandruff without any expensive shampoo. I am very prone to dandruff and shampoo doesn't work for me, actually I don't like using shampoo, why? first anti dandruff shampoos does not remove dandruff properly and after few hours of shampoo itching starting again. second It makes my hair very silky that I am not able to style my hair, my hair remains silky for as long as a week. So, I have to find some other treatment and for that first I have to understand, What is dandruff and what causes it? So, lets understand and then I will tell you how I get rid of dandruff. Image by  Hai Phung In an abundant forest of hairs, Malassezia is equipped with everything it could ever need. Feasting constantly, it’s in paradise. But wait— what’s this? In fact, Malassezia is a type of yeast that lives and dines on all of our scalps. And in about half of the human population, its activity causes dandruff. So, why do some people

How stock market works?

So, last year I decided to get into the stock market and started learning about it. I learned a lot of things in past months and I you also wanted to get into the stock market then you should have some knowledge about it. so today I am here to answer the basic question in stock market. How stock market works?    Image by  Jason Briscoe In the 1600s the Dutch East India Company employed hundreds of ships to trade gold, porcelain, spices, and silks around the globe. But running this massive operation wasn’t cheap. In order to fund their expensive voyages, the company turned to private citizens– individuals who could invest money to support the trip in exchange for a share of the ship’s profits. This practice allowed the company to afford even grander voyages, increasing profits for both themselves and their savvy investors. Selling these shares in coffee houses and shipping ports across the continent, the Dutch East India Company unknowingly invented the world’s first stock market. Since

Coronavirus explained

  Image by  CDC For almost a decade, scientists chased the source of a deadly new virus through China’s tallest mountains and most isolated caverns. They finally found it here: in the bats of Shitou Cave. The virus in question was a coronavirus that caused an epidemic of severe acute respiratory syndrome, or SARS, in 2003. Coronaviruses are a group of viruses covered in little protein spikes that look like a crown— or "corona" in Latin. There are hundreds of known coronaviruses. Seven of them infect humans, and can cause disease. The coronavirus SARS-CoV causes SARS, MERS-CoV causes MERS, and SARS-CoV-2 causes the disease COVID-19. Of the seven human coronaviruses, four cause colds, mild, highly contagious infections of the nose and throat. Two infect the lungs, and cause much more severe illnesses. The seventh, which causes COVID-19, has features of each: it spreads easily, but can severely impact the lungs. When an infected person coughs, droplets containing the virus spray

World's Largest Dam - Three Gorges Dam

Image by  Dong Zhang   In 2018, a single power plant produced more energy than the world’s largest coal-powered and gas-powered plants combined. And rather than using finite fossil fuels, this massively powerful plant relied on a time-tested source of renewable energy: running water. Stretching over 2.3 kilometers, China’s Three Gorges Dam isn’t just the world’s largest hydroelectric plant. It’s capable of producing more energy than any other power plant on Earth. So what allows Three Gorges to generate all this power? And how do hydroelectric plants work in the first place? A hydroelectric dam is essentially a massive gate, which redirects a river’s natural flow through a large pipe called a penstock. Rushing water flows through the penstock and turns the blades of a turbine, which is attached to a generator in an adjacent power station. The turning of the blades spins coils of wire inside a magnetic field, producing a steady supply of electricity. Because the penstocks can be sealed