Questions tagged [autoencoders]
Feedforward neural networks trained to reconstruct their own input. Usually one of the hidden layers is a "bottleneck", leading to encoder->decoder interpretation.
650 questions
1 vote
0 answers
40 views
Why aren't Data Augmentations used when training autoencoder or neural-based compressors for images / video?
I was curious if anyone happens to know why data augmentations (like color jitter, random cropping, etc) appear to not be always used when training autoencoder or neural-based compressors for images ...
2 votes
0 answers
52 views
Should Feature Maps be considered for Dimensionality Reduction with Convolutional AutoEncoders
I am trying to use a convolutional autoencoder to perform dimensionality reduction with the ultimate goal of reconstructing temperature fields. As I understand it, the goal of an autoencoder is to ...
0 votes
0 answers
39 views
Which $x$ is actually computed by the decoder in VAEs, for a given $z$?
I get that the decoder computes $p_\theta(x\mid z)$. Here $\theta$ is close to the true MLE which is intractable. But still $p_\theta(\cdot\mid z)$ is a probability distribution, and the decoder ...
1 vote
1 answer
84 views
Are VAEs considered explainable AI?
Are VAEs considered explainable AI? To me, they are because the latent variables are interpretable, e.g, you change one and you might see its effects on the head rotation (for a dataset of faces, for ...
3 votes
1 answer
132 views
Simple question about VAEs
I have trouble understanding the minimization of the KL divergence. In this link https://www.ibm.com/think/topics/variational-autoencoder They say, "One obstacle to using KL divergence for ...
5 votes
2 answers
329 views
Backpropagating regularization term in variational autoencoders
Setup The variational autoencoder (VAE) loss is given by the following (see here, for example): $$L = - \sum_{j = 1}^J \frac{1}{2} \left(1 + \log (\sigma_i^2) - \sigma_i^2 - \mu_i^2 \right) - \frac{1}{...
0 votes
0 answers
39 views
Evidence lower bound in Newtonian VAEs
I am reading this paper https://openaccess.thecvf.com/content/CVPR2021/papers/Jaques_NewtonianVAE_Proportional_Control_and_Goal_Identification_From_Pixels_via_Physical_CVPR_2021_paper.pdf Are the ...
3 votes
1 answer
102 views
Is this overfit?
I am quite new to ML and I am developing my first Variational AutoEncoder (VAE), which is composed of a CNN encoder (4 layers) and a CNN decoder (4 layers). The input images are of size 128x128 and ...
0 votes
0 answers
44 views
How to improve segregation of images in VAEs?
I have developed a VAE to understand if it is able to distinguish lung images of COVID-19, Normal images, or images with Viral Pneumonia. The VAE is composed of CNN encoder and CNN decoder (shown ...
1 vote
1 answer
112 views
Linear VAE and pPCA
I am looking into the relationship between linear Variational Autoencoder (VAE) and probabilistic PCA (pPCA) presented by Lucas et al. (2019). Don't blame the elbo! paper In the official ...
1 vote
1 answer
85 views
Why is the target 𝑦 used as an input to the encoder in a semi-supervised VAE model?
As mentioned in the title, I understand the mathematical derivation of equations (6-7) in Kingma's original paper. \begin{equation} \log p_\theta(\mathbf{x}, y) \geq \mathbb{E}_{q_\phi(\mathbf{z} \mid ...
0 votes
0 answers
94 views
Weighted Fusion of VAE Gaussian Distributions
Say you have 4 stacked output vectors of 4 different VAEs: $B \times 512 \times 4$ These $512$ elements correspond to $256 \ \mu$ & $256 \ \ln\sigma^2$ (log-variances) of four multi-variate ...
2 votes
2 answers
273 views
Intuition behind generative methods for imputing missing data
I’m learning different approaches to impute a tabular dataset of mixed continuous and categorical variables, and with data assumed to be missing completely at random. I converted the categorical data ...
0 votes
0 answers
9 views
LSTM Variational auto encoder not learning with Pytorch [duplicate]
I'm trying to train an LSTM Variational Autoencoder, but I cannot figure out why the model is not making any progress, the loss gets stuck immediately. Here is my code and training loop. The sequences ...
0 votes
0 answers
33 views
Apply PCA to multi individual time series dataset
Let's imagine I have time series data for 50 users and 20 features per user: User1_ts(F1, ...F20), User2_ts(F1, ...F20), ...User50_ts(F1, ... F20). F20 is my target variable for estimation, and each ...