profile

Machine Learning for Medical Imaging

Object detection in 3D made simple

Published about 1 year agoΒ β€’Β 2 min read

Hi Reader,,

Welcome to the PYCAD newsletter, where every week you receive doses of machine learning and computer vision techniques and tools to help you learn how to build AI solutions to empower the most vulnerable members of our society, patients.

Object Detection on 3D Point Clouds

Have you heard of Voxel R-CNN?

It's a dope technique for 3D object detection. This is some cutting-edge stuff, and it's important for a few reasons.
​
First of all, Voxel R-CNN is a two-stage framework that consists of a 3D backbone network, a 2D bird-eye-view (BEV) Region Proposal Network, and a detect head.
​
This means that it's using some serious firepower to get the job done!
​
And that's not all!
​
Voxel RoI Pooling is also a key feature of this technique. It's designed to extract RoI features directly from raw features for further refinement.
​
This is important because it allows for more accurate object detection, which is crucial in applications like autonomous vehicles.
​
So, how does it all work?
​
Well, the point clouds are first divided into regular voxels and fed into the 3D backbone network for feature extraction.
​
Then, the 3D feature volumes are converted into BEV representation, on which the 2D backbone and RPN are applied for region proposal generation.
​
Finally, Voxel RoI Pooling directly extracts RoI features from the 3D feature volumes, which are then exploited in the detect head for further box refinement.

​

Autoencoders Demystified

Did you know that autoencoders were one of the first wins when it comes to generating images from latent spaces?

Here’s a small overview of them.

An autoencoder is a neural network that’s composed of 2 parts: an encoder and a decoder.

The output of the encoder is called a latent vector.

This same vector is used as an input to the decoder.

Here’s how an autoencoder handles a data point such as an image from start to finish:

1 - First, it takes the image and passes it through a series of conv layers followed by flattening and fully connected layers. This is the encoder

2 - The output of the first part is a vector, let’s call it β€œz”.

3 - β€œz” is used as an input to the decoder, which contains a series of transposed conv layers that grow the size of β€œz” until it’s a full image.

➑ Here are some notes:

β€œz” is also called an embedding. A term that we often hear when we talk about generative models such as GPT3.

It’s called like this because it embeds information found in the original input image into a smaller space.

➑ There are 2 main kinds for this type of generative AI:

  • Autoencoders.
  • Variational autoencoders (VAE).

The difference between the two is:

  • For autoencoders, the input is mapped to a single point in the latent space.
  • For VAEs, the input is mapped to a probability distribution (usually a Gaussian distribution).

​

News of the day: ChatGPT API is out!

twitter profile avatar
OpenAI
Twitter Logo
Twitter Logo
@OpenAI
ChatGPT and Whisper are now available through our API (plus developer policy updates). We ❀️ developers: openai.com/blog/introduci…
link visual
Introducing ChatGPT and Whisper APIs
Developers can now integrate ChatGPT and Whisper models into their apps and products through our API...
openai.com
March 1st 2023
2,447
Retweets
9,602
Likes

​

(Fake) Quote of the day by ChatGPT


What'd you think of today's edition?

Machine Learning for Medical Imaging

by Nour Islam Mokhtari from pycad.co

πŸ‘‰ Learn how to build AI systems for medical imaging domain by leveraging tools and techniques that I share with you! | πŸ’‘ The newsletter is read by people from: Nvidia, Baker Hughes, Harvard, NYU, Columbia University, University of Toronto and more!

Read more from Machine Learning for Medical Imaging

Hi Reader,, Welcome to the PYCAD newsletter, where every week you receive doses of machine learning and computer vision techniques and tools to help you learn how to build AI solutions to empower the most vulnerable members of our society, patients. TotalSegmentator : Whole Body Segmentation at your Fingertips This free tool available online can do full body segmentation, it's called TotalSegmentator. I have already mentioned this tool in a previous edition of the newsletter, but in this...

9 days agoΒ β€’Β 3 min read

Hello Reader, Welcome to another edition of PYCAD newsletter where we cover interesting topics in Machine Learning and Computer Vision applied to Medical Imaging. The goal of this newsletter is to help you stay up-to-date and learn important concepts in this amazing field! I've got some cool insights for you below ↓ A Medical Imaging Expert Told Me This Recently I saw a post on LinkedIn where a medical imaging expert showcased his work of segmenting the lungs and its bronchial trees. You can...

16 days agoΒ β€’Β 2 min read

Hello Reader, Welcome to another edition of PYCAD newsletter where we cover interesting topics in Machine Learning and Computer Vision applied to Medical Imaging. The goal of this newsletter is to help you stay up-to-date and learn important concepts in this amazing field! I've got some cool insights for you below ↓ How we helped accelerate inference time for a client's AI product Below is a screenshot of a benchmark we did for a client of ours. The goal was to accelerate inference time. This...

22 days agoΒ β€’Β 3 min read
Share this post