Photo and video access in DeDup: Android 1.5.3 vs iPhone 1.0.1

This post compares how DeDup 1.5.3 on Android and DeDup 1.0.1 on iPhone ask for access to your photos and videos. Both can run with access to only the photos you pick. The way each app asks, and the wording it shows, differs.

Android, DeDup 1.5.3

Android splits media access into separate permissions, and the code picks them by Android version:

• Photos: on Android 14 and newer, DeDup asks for image access plus the "selected photos" permission. Android 13 uses image access alone. Android 10 to 12 use the general storage read permission. Android 9 and older also ask for storage write, which the manifest says is needed for deleting.
• Videos: Android 13 and newer ask for video access. Older versions use the storage permissions above.
• Audio is its own permission. Contacts and notifications are separate permissions too.
• "All files access" is a separate special permission on Android 11 and newer. A note in the manifest says it's needed only for the File Browser and the document and APK scanner, and that photo and video scanning doesn't use it.

When you open the Image Scanner without access, DeDup shows "Gallery Access Needed" with a Grant Access button. The Video Scanner shows "Video Access Needed".

Settings has a Permissions section with a row for Photos, Videos, Audio, Contacts, Notifications and All files access. Each row shows Allowed, Not allowed or, for Photos and Videos on Android 14 and newer, "Selected only". Tapping a row asks for the permission if it's missing. If it's already allowed or selected-only, the row opens Android's app settings so you can change it.

What "Selected only" does to the scanner: the screen that guards the scanners wants every permission in the group, including full image access. Read as written, selected-only access doesn't pass that check, so you'd see the Grant Access card. I read that code and didn't run it. Elsewhere, the code notes that opening an item can fail when access is partial or revoked, and shows a message instead of crashing.

iPhone, DeDup 1.0.1

• iOS has one photo library permission that covers photos and videos. DeDup asks for read and write access, because deleting needs write.
• The usage text in the app reads: "DeDup analyzes your photos and videos on-device to find duplicates, blurry shots and large files. Nothing is uploaded."
• The prompt isn't shown at launch in the code I read. It appears when you tap "Allow Access" on the dashboard card or in the Files view.
• The dashboard card changes with the state. Not asked yet: a request message. Off: "Photo access is off. Turn it on in Settings to scan your library", with an Open Settings button. Limited: "Limited access: only the photos you selected are scanned", with a "Change in Settings" button.
• DeDup treats full and limited access as readable, so scanning runs on whatever iOS lets it see. It rechecks when the app becomes active again.
• I found no code that opens the iOS limited-library picker from inside DeDup. The button goes to iOS Settings.
• Scanning asks iOS for local images only. Previews and thumbnails in review screens allow iOS to fetch from iCloud when needed.

Side by side

• Android: several permissions, chosen by Android version. iPhone: one permission.
• Android: a "Selected only" label in Settings. iPhone: a "Limited access" banner on the dashboard.
• Both: you can change access later in the system settings.

Scope of this post

Checked against: DeDup 1.5.3 source code (Android) and DeDup 1.0.1 source code (iPhone).

Not tested on a device: any permission dialog, the "Selected only" and "Limited access" states, or what the scanners show with partial access. Everything above comes from reading the code, the manifest, the usage text and the on-screen strings.