Foundations
Introduction to Image Processing
Explore how arrays become images, how convolution removes fine detail, and how derivatives reveal boundaries.
Open notebooks · Mathematical data science
Explore the mathematics of images, learning, and geometry.
Read an experiment, run the code, and follow the ideas.
58 tours
Foundations
Explore how arrays become images, how convolution removes fine detail, and how derivatives reveal boundaries.
Foundations
Represent the same image in Fourier and wavelet coordinates, then reconstruct it from a limited number of coefficients.
Foundations
Use interactive controls to vary how many transform coefficients an image keeps.
Foundations
Compare wavelet and discrete cosine representations for image approximation.
Foundations
Découvrez comment représenter une image par une matrice, modifier son contraste et construire des filtres simples.
Wavelets & compression
Build a separable orthogonal wavelet transform from its analysis filters and reconstruct the image with the corresponding synthesis filters.
Wavelets & compression
Extend multiscale image processing to a three-dimensional volume.
Wavelets & compression
Compare linear and nonlinear approximations in several orthogonal bases.
Wavelets & compression
Construct Huffman codes from symbol probabilities and check that encoding followed by decoding recovers the data exactly.
Image restoration
Study denoising as a tradeoff between suppressing random fluctuations and retaining useful detail.
Image restoration
Remove noise by shrinking wavelet coefficients and reconstructing the image.
Image restoration
Process neighboring wavelet coefficients together instead of thresholding each coefficient independently.
Image restoration
Find similar image patches and average their center pixels using similarity weights.
Image restoration
Replace local pixel averages with order statistics such as medians and quantiles.
Image restoration
Choose denoising parameters by estimating reconstruction risk from the noisy observation itself.
Inverse problems
Recover an image from a blurred observation by balancing data fidelity with a regularity penalty.
Inverse problems
Reconstruct missing pixels by promoting sparsity in a wavelet representation.
Inverse problems
Recover a low-rank matrix from a subset of its entries.
Inverse problems
Investigate when a sparse vector can be recovered from fewer measurements than unknowns.
Inverse problems
Learn an overcomplete collection of image atoms by alternating sparse coding and dictionary updates.
Optimization
Follow gradient descent on smooth objectives and apply it to image restoration.
Optimization
Develop gradient descent for quadratic objectives, image denoising, and constrained inpainting.
Optimization
Recover a sparse signal by combining a smooth data-fidelity gradient with soft thresholding.
Optimization
Solve total-variation denoising through its dual formulation.
Optimization
Recover a sparse signal under exact linear constraints by alternating two proximity operators.
Optimization
Implement a primal–dual algorithm for total-variation inpainting and denoising.
Optimization
Approach constrained optimization from the interior of the feasible set using a logarithmic barrier.
Optimization
Reformulate a sparse regression objective through a smooth factorization and an inner linear solve.
Optimal transport
Compute a minimum-cost coupling between discrete probability distributions.
Optimal transport
Replace a linear transport problem with a smooth entropically regularized objective.
Optimal transport
Use Sinkhorn scaling to compare and transform discrete distributions.
Optimal transport
Explore refinements of entropic transport beyond basic alternating scaling.
Optimal transport
Transport a continuous distribution toward a finite set of weighted points.
Optimal transport
Allow transport to create or remove mass when exact marginal matching is inappropriate.
Geometry & segmentation
Locate image boundaries using derivatives at several scales.
Geometry & segmentation
Evolve a closed curve under smoothing and image-dependent forces.
Geometry & segmentation
Represent a moving contour as the zero level of a function and evolve that function on a grid.
Geometry & segmentation
Propagate a distance front through a weighted domain, first with a graph update and then with an eikonal update.
Geometry & segmentation
Recover a low-dimensional representation of a curved point cloud using neighborhood-graph distances.
Geometry & segmentation
Map a triangulated surface into the plane by fixing its boundary and solving for interior coordinates.
Geometry & segmentation
Smooth noisy vertex positions using discrete differential operators on a triangulated surface.
Signals & graphics
Separate several audio sources from a smaller number of mixtures using sparse time-frequency structure.
Signals & graphics
Generate random textures with prescribed second-order statistics using Fourier-domain operations.
Signals & graphics
Advect a velocity field and an image through a two-dimensional domain.
Machine learning
Explore a labeled dataset through principal components, neighborhood classifiers, and clustering.
Machine learning
Fit and compare linear regression models with quadratic and sparse penalties.
Machine learning
Turn linear scores into class probabilities and optimize a logistic loss.
Machine learning
Replace full gradients with random sample updates and compare the resulting trajectories.
Machine learning
Build a small neural network and differentiate its loss through successive layers.
Machine learning
Train a multilayer network to approximate a nonlinear function.
Machine learning
Implement forward and backward propagation, then compare manual derivatives with automatic differentiation.
Machine learning
Estimate a structured signal under simplex constraints and a trend-filtering penalty.
Machine learning
Synthesize a texture by matching Gram matrices of pretrained convolutional features.
Machine learning
Infer sparse conditional dependencies by estimating a Gaussian precision matrix.
Machine learning
Evolve a cloud of particles under pairwise kernel interactions and compare analytic and automatic gradients.
Machine learning
Construct prediction regions by comparing a candidate observation with observed conformity scores.
Machine learning
Study forward noising and reverse sampling on a one-dimensional Gaussian mixture.
Machine learning
Implement Gaussian-mixture diffusion and score learning with JAX and Flax.
Try a broader term such as “image”, “optimization”, or “transport”.