OpenZoom

OpenZoom is a Windows-only camera magnifier built around Qt 6, Media Foundation, Direct3D 12, and an optional CUDA processing path. The current codebase already supports live camera capture, CPU and GPU frame processing, a two-stage preset/advanced UI, rotation-aware presentation, persistent settings, photo snapshots, and H.264 MP4 recording.

Current Capabilities

• Media Foundation camera enumeration with per-device mode listing (width x height @ fps).
• CPU frame pipeline for format conversion, rotation, black-and-white thresholding, zoom, Gaussian blur, temporal smoothing, and debug compositing.
• Direct3D 12 presenter for swap-chain output plus GPU texture readback for recording and snapshots.
• CUDA external-memory interop path with black-and-white, zoom, Gaussian blur, temporal smoothing, focus marker, and spatial sharpening via NVIDIA NIS or AMD FSR 1.0 style kernels.
• Stage-1 quick modes backed by full stage-2 advanced configurations, including promotion of advanced tuning into user-defined quick options.
• CPU fallback when CUDA interop is unavailable or debug view is enabled.
• OCR via tesseract.exe, VLM via an OpenAI-compatible HTTP endpoint, and an in-app assistive overlay.
• Session persistence in %APPDATA%\OpenZoom\OpenZoom\settings.json.
• Processed output capture to output/img/IMG_*.jpg and output/vid/VID_*.mp4 next to the executable.

Status

OpenZoom is no longer just a CPU-only shell. The CPU path is the most deterministic debugging path, while the CUDA path is active when the D3D12/CUDA interop surface initializes successfully. When GPU processing cannot be used, the app falls back to the CPU pipeline automatically and exposes that state in the UI.

Prerequisites

• Windows 10 or Windows 11.
• Visual Studio 2022 with the Desktop C++ workload and Windows SDK.
• Qt 6.9.3 for msvc2022_64, or matching overrides via QT_PREFIX / Qt6_DIR.
• CMake 3.23 or newer.
• NVIDIA GPU plus CUDA Toolkit 13.x if you want the CUDA path.

Build And Run

From a Visual Studio x64 developer prompt or a PowerShell 7 session (pwsh.exe) with MSVC, Qt, and optionally CUDA on PATH:

scripts\build_and_run.bat

From the WSL/Linux agent shell, run Windows-side commands through PowerShell 7 with pwsh.exe -NoProfile -Command '...', for example pwsh.exe -NoProfile -Command 'Get-Date'.

The helper script:

• configures build\ with the Visual Studio 2022 generator,
• clears stale CMake cache entries when the source path changes,
• builds open_zoom,
• prefers build\cmake\Release\open_zoom.exe when launching,
• runs windeployqt automatically when it can find the Qt runtime.

If Windows reports missing Qt6*.dll files, add the Qt bin directory to PATH or point QT_PREFIX / Qt6_DIR at the correct installation.

Alternative Builds

CMake presets

cmake --preset msvc-release
cmake --build --preset msvc-release-build

Available presets live in cmake/CMakePresets.json:

• msvc-debug
• msvc-release
• msvc-cpu

CPU-only build

cmake -S . -B build-cpu -G Ninja -DCMAKE_BUILD_TYPE=Release -DCMAKE_PREFIX_PATH="C:/Qt/6.9.3/msvc2022_64" -DOPENZOOM_ENABLE_CUDA=OFF
cmake --build build-cpu

Release bundle

scripts\build_release_bundle.bat

This produces dist\OpenZoom\ with open_zoom.exe, Qt runtime files, LICENSE, README.txt, and THIRD_PARTY_LICENSES.md. CUDA redistributables are copied when they are available on the machine.

Runtime Controls

• Quick Modes is the primary stage-1 UI: choose task-oriented presets like reading, high contrast, OCR assist, or scene explain.
• Advanced Tuning opens the stage-2 panel with the full set of low-level controls.
• Save As Quick Option promotes the current advanced setup into a reusable stage-1 preset.
• Camera selects the active Media Foundation device.
• Modes shows the discovered capture modes for the selected camera.
• Rotation rotates the pipeline in 90 degree clockwise steps before downstream processing.
• Black & White applies thresholded monochrome conversion.
• Zoom enables the magnifier and focus-point controls.
• Gaussian Blur applies the CPU or CUDA blur stage with configurable sigma and supported discrete radii.
• Temporal Smooth applies an exponential running average.
• OCR Assist, Scene Explain, and Assistive Overlay drive asynchronous assistive analysis and on-screen text overlays.
• Spatial Sharpen enables the CUDA sharpening/upscaling stage and lets you choose NIS or FSR-style processing when the GPU path is active.
• Debug View switches to the CPU composite grid so intermediate stages can be inspected.
• Show Focus Point overlays the current zoom center on the presented output.
• Capture Photo saves the current processed frame to output/img/.
• Start Recording writes processed video to output/vid/ as H.264 MP4, with a 12 hour cap per file.

Navigation And Interaction

• Ctrl + mouse wheel: zoom around the cursor.
• Mouse wheel: pan while zoomed.
• Middle mouse drag: pan the zoom focus.
• Arrow keys: nudge the zoom focus.
• Virtual Joystick: shows an on-canvas joystick overlay for panning.

Persistence And Output Paths

• Settings persist to %APPDATA%\OpenZoom\OpenZoom\settings.json, including the selected quick mode, current advanced configuration, and user-created quick options.
• Snapshots are written under output/img/ relative to the executable.
• Recordings are written under output/vid/ relative to the executable.

Assistive Runtime Configuration

• OCR uses tesseract.exe. If it is not on PATH, set OPENZOOM_TESSERACT_PATH.
• VLM mode uses an OpenAI-compatible chat/completions endpoint.
• Configure VLM with:
  • OPENZOOM_VLM_API_URL
  • OPENZOOM_VLM_API_KEY
  • OPENZOOM_VLM_MODEL
  • optional OPENZOOM_VLM_PROMPT

Repository Layout

• src/app/ - application lifecycle, settings persistence, and interaction wiring.
• src/capture/ - Media Foundation camera discovery and capture loop.
• src/common/ - CPU frame pipeline, image processing helpers, and Media Foundation recording wrapper.
• src/d3d12/ - Direct3D 12 presenter, swap chain, upload, and readback logic.
• src/cuda/ - CUDA interop surface and kernels.
• src/ui/ - Qt widgets, overlays, and event routing.
• include/openzoom/ - public headers mirroring the source layout.
• docs/ - architecture notes, code reference, progress tracking, and licensing docs.
• scripts/ - build, bundle, and validation helpers.

Documentation Map

• docs/README.md for the architecture overview.
• docs/code_reference.md for the current class and file map.
• docs/hardcoded_paths.md for machine-specific defaults.
• docs/progress.md for implementation status.
• docs/THIRD_PARTY_LICENSES.md for redistribution notes.

License

This project is dual-licensed:

• GPL-3.0 via LICENSE
• Commercial licensing by direct arrangement with the project owner

By contributing, you agree that your changes may be distributed under both terms. Third-party notices are summarized in docs/THIRD_PARTY_LICENSES.md.