VKQuickLook

Native macOS Finder thumbnails and Quick Look previews for Keyence .vk4 and .vk6 measurement files.

VKQuickLook is an independent open-source project and is not affiliated with, endorsed by, or sponsored by KEYENCE CORPORATION. KEYENCE is used only to identify the file formats this tool supports.

This repository contains:

• A native Swift Quick Look Thumbnail extension.
• A native Swift Quick Look Preview extension.
• A Swift command-line renderer, VKQuickLookRender, built from the same renderer source as the Finder extensions.
• Build, install, and validation scripts for local development and signed distribution builds.

Scope

Supported by the Finder extension:

• .vk4
• .vk6

Not supported by this extension:

• HDF5
• stitched HDF5
• teaching CSVs
• arbitrary raster images

Architecture

The installed Finder extension renders natively in Swift because Quick Look extensions run in a sandbox and should not depend on external runtimes.

The native path is intentionally narrow:

• VK6 thumbnails/previews use the wrapper BMP preview in the VK6 container.
• VK4 thumbnails use embedded 24-bit thumbnail sections in the VK4 offset table.
• VK4 previews use full 24-bit color_light, then color_peak, then thumbnail fallbacks.

The repository is Swift-only. VKQuickLookRender and the Finder extensions share the same native renderer source.

Install For Local Use

scripts/build_macos_quicklook.sh --install

The default install builds and ad-hoc signs the app locally; users do not need the maintainer's signing certificate or an Apple Developer account for a source build. A real Apple signing identity is optional, but can make local extension registration more reliable.

For a signed local build:

scripts/build_macos_quicklook.sh \
  --install \
  --bundle-id-prefix "com.vsoptomech.vkquicklook" \
  --type-id-prefix "com.vsoptomech.keyencevkx" \
  --sign-identity "Apple Development: Your Name (TEAMID)"

The app is installed to:

~/Applications/VKQuickLook.app

Validate

Swift renderer CLI:

tmpdir=$(mktemp -d)
scripts/build_macos_quicklook.sh --output-dir "$tmpdir/build" --skip-codesign
"$tmpdir/build/VKQuickLookRender" thumbnail path/to/file.vk6 --output "$tmpdir/thumb.png" --metadata-json "$tmpdir/thumb.json"
file "$tmpdir/thumb.png"

Finder thumbnail extension:

qlmanage -r
qlmanage -r cache
qlmanage -t -s 512 -o /tmp path/to/file.vk6
qlmanage -t -s 512 -o /tmp path/to/file.vk4

Quick Look preview extension:

qlmanage -p path/to/file.vk4
qlmanage -p path/to/file.vk6

Project checks:

scripts/test_swift_renderer.sh
scripts/build_macos_quicklook.sh --skip-codesign

Distribution Notes

For public binary distribution, sign with Developer ID and notarize the app bundle. The source build scripts intentionally avoid a checked-in Xcode project and use swiftc directly.

Licensed under the MIT License.

Contact: vitek@vsoptomech.com

Additional Documentation

• Install and signing guide
• macOS Quick Look implementation notes