pixelflow

GPU Texture Reservoir Computing. A minimal, honest library that treats image pixels on a GPU texture as a fixed random reservoir — evolving under local cellular-automaton rules expressed as fragment shaders — and trains a linear readout on top for image classification, PDE solving, and time-series tasks.

Live demo: https://huggingface.co/spaces/Agnuxo1/pixelflow

Status: v0.1.0 alpha. The core is functional and tested; performance work and extra backends are in progress. This library is research software — it does not claim to beat state-of-the-art CNNs, but it is a clean, reproducible implementation of a legitimate reservoir-computing idea, and it is honest about what works and what doesn't.

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What it is

Reservoir computing separates a dynamical system (the "reservoir") from a simple trainable readout. Only the readout is trained; the reservoir is fixed. If the reservoir has rich enough internal dynamics, a linear readout can solve surprisingly hard tasks.

pixelflow uses a 2D GPU texture as the reservoir state. Each pixel is a unit; neighbours interact under a local rule implemented as a fragment shader (or an equivalent numpy kernel on CPU). After steps iterations, the final texture is flattened into a feature vector, and an sklearn linear model (Ridge, Logistic) is trained on those features.

Three built-in rules:

Rule	Dynamics	Use case
diffusion_reaction	Gray-Scott reaction-diffusion	Rich pattern formation — image features
life_like	Continuous Conway-style majority rule	Binary-ish inputs, texture classification
wave	Discrete wave equation (amplitude + velocity)	Eikonal / path-planning tasks

Install

pip install pixelflow              # core + CPU backend
pip install pixelflow[gpu]         # adds moderngl + glfw (OpenGL 3.3 GPU backend)
pip install pixelflow[cuda]        # adds cupy-cuda12x (CUDA backend)
pip install pixelflow[datasets]    # adds torchvision / pillow for dataset loaders
pip install pixelflow[all]         # everything

Quickstart

import numpy as np
from pixelflow import Reservoir, ReservoirConfig, RidgeReadout
from pixelflow.tasks.synthetic import two_moons

X_train, y_train = two_moons(n=500, noise=0.2, seed=0)
X_test,  y_test  = two_moons(n=200, noise=0.2, seed=1)

cfg = ReservoirConfig(
    width=32, height=32, channels=4,
    steps=8, rule="diffusion_reaction",
    input_encoding="project", seed=0,
)
res = Reservoir(cfg, backend="cpu")          # or backend="moderngl"

F_train = res.transform(X_train)             # (500, 32*32*4)
F_test  = res.transform(X_test)

readout = RidgeReadout(alpha=1.0).fit(F_train, y_train)
print(f"accuracy: {readout.score(F_test, y_test):.3f}")

Run the bundled example:

python examples/quickstart.py

Backends

• cpu — pure NumPy. Always available. Reference implementation.
• moderngl — headless OpenGL 3.3 core via moderngl. Requires a GPU with working OpenGL drivers. Install with pip install pixelflow[gpu].
• cuda — CuPy-backed CUDA implementation. Requires an NVIDIA GPU and matching CUDA toolkit (12.x or 13.x). Install with pip install pixelflow[cuda].

All three backends produce numerically equivalent outputs (CPU vs moderngl: max abs diff < 1e-5; CPU vs CUDA: max abs diff < 1e-3), verified in tests/test_moderngl_backend.py and tests/test_cuda_backend.py.

Benchmarks

All numbers below are measured (raw JSON under benchmarks/results/) on Windows 10 + Python 3.13, RTX 3090 + Ryzen 5950X. Losses vs. baseline are reported as-is, never hidden.

MNIST (60k train / 10k test)

Rule	Grid	Steps	Backend	Transform time	Test acc.	Raw-pixel baseline
wave	32×32×4	4	cpu	24.15 s	0.9281	0.9261
wave	32×32×4	4	cuda (batched)	5.81 s (4.2× faster)	0.9281	0.9261
diffusion_reaction	32×32×4	8	cpu	72.43 s	0.9213	0.9261

GPU speedup (batched CUDA v0.3, RTX 3090)

Workload	CPU	moderngl	CUDA batched	Speedup vs CPU
N=1000, 64×64, 32 steps, diffusion_reaction	5.00 s	25.95 s	0.28 s	17.95×
N=2000, 32×32, 16 steps, wave	2.13 s	46.49 s	0.17 s	12.32×

CIFAR-10 (10k grayscale subset)

Rule	Grid	Steps	Test acc.	Raw-pixel baseline
wave	32×32×4	6	0.2430	0.2521

Honest negative result: on grayscale CIFAR-10 with a 10k subset, the reservoir slightly underperforms the raw-pixel baseline. RGB + colour-aware encoding is a follow-up experiment.

Eikonal equation (reference vs wave reservoir)

Mean relative arrival-time error of the wave reservoir against a fast-marching reference (constant-speed field, variable source):

Grid	Source	Speed field	Mean rel. err.
32×32	center	constant	0.064
64×64	center	constant	0.066
64×64	off-center	constant	0.313
64×64	center	radial	0.047

The reservoir is a crude wave simulator, not an Eikonal solver — the 30% error near boundaries is expected and documented.

Why bother?

Reservoir computing has three practical strengths:

1. Training is cheap — only the readout is trained (closed-form for Ridge).
2. The reservoir is reusable — same features serve multiple downstream tasks.
3. Non-standard hardware is plausible — any substrate with rich local dynamics (optical systems, memristor arrays, analog chips) can act as a reservoir. GPU textures are a software twin of that.

pixelflow is not trying to beat ResNet on ImageNet. It's a clean testbed for reservoir-computing research that happens to run fast on commodity GPUs, and a pedagogical artifact for the "rendering is thinking" intuition.

Project layout

pixelflow/
├── pixelflow/
│   ├── core/          # Reservoir, ReservoirConfig, CA rules, encoders
│   ├── backends/      # cpu (numpy), moderngl (GPU)
│   ├── readouts/      # Ridge, Logistic (sklearn wrappers)
│   └── tasks/         # MNIST, Eikonal, synthetic
├── tests/             # pytest suite (CPU-only tests always run)
├── benchmarks/        # honest measurements with JSON outputs
├── examples/          # runnable demos
├── paper/             # draft paper + figures
└── docs/              # API contract, design notes

Citation

If you use pixelflow in research, please cite:

@software{angulo_pixelflow_2026,
  author  = {Angulo de Lafuente, Francisco},
  title   = {pixelflow: GPU Texture Reservoir Computing},
  year    = {2026},
  version = {0.1.0},
  url     = {https://github.com/Agnuxo1/pixelflow},
  license = {Apache-2.0}
}

License

Apache-2.0. See LICENSE.

Author

Francisco Angulo de Lafuente GitHub: @Agnuxo1

Acknowledgements

pixelflow distills a single clean idea from several years of experiments across the NEBULA / NeuroCHIMERA / RED_NEURONAL_ANALOGICA project family. The core reservoir-computing concept builds on classical work by Jaeger (Echo State Networks) and Maass (Liquid State Machines); the GPU cellular-automaton substrate is inspired by physical reservoir computing literature (Tanaka et al. 2019) and practical fragment-shader-as-compute patterns.