Scan and Thumbnail Pipeline

Wed, 25 Mar 2026 00:00:00 +0000

RawCull — Scan and Thumbnail Pipeline

This document describes the complete execution flow from the moment a user opens a catalog folder to the point where all thumbnails are visible in the grid. It covers the actors involved, the data flow between them, the concurrency model, five performance bugs that were found and fixed, and the measured results on a real catalog of 809 Sony A1 ARW files stored on an external 800 MB/s SSD.

Sony MakerNote Parser

Wed, 25 Mar 2026 00:00:00 +0000

Sony MakerNote Parser — Focus Point Extraction

Files covered:

RawCull/Enum/SonyMakerNoteParser.swift

RawCull/Model/ViewModels/FocusPointsModel.swift

RawCull/Actors/ScanFiles.swift

RawCull/Views/FocusPoints/FocusOverlayView.swift

Overview

RawCull extracts autofocus (AF) focus point coordinates directly from Sony ARW raw files without requiring any external tools such as exiftool. The parser supports the ILCE-1 (A1), ILCE-1M2 (A1 II), ILCE-7M5 (A7 V), ILCE-7RM5 (A7R V), and ILCE-9M3 (A9 III).

The focus location is stored inside the Sony proprietary MakerNote block embedded in the EXIF data of every ARW file. SonyMakerNoteParser (declared as an enum to prevent instantiation) navigates the binary TIFF structure to locate and decode this data. It also exposes helpers for locating and reading the three JPEG images embedded in every ARW file, and a verbose diagnostic walk used by the body-compatibility test suite.

Sony on RawCull

Scan and Thumbnail Pipeline

RawCull — Scan and Thumbnail Pipeline

Sony MakerNote Parser

Sony MakerNote Parser — Focus Point Extraction

Overview