Keystone Photo Studio
Perspective correction & AI corner fill for iPhone
Fix perspective. Fill the corners. Keep every pixel.
Keystone Photo Studio straightens leaning buildings and converging verticals, then fills the empty corners with generative AI — at your photo's full resolution, with Display P3 color and native HDR preserved end to end. No account required to start.
Download on the App StoreWhat it is
A precision photo studio for architecture and street shots
Point your camera up at a building and the walls lean in. Keystone fixes that — it detects the converging vanishing lines and straightens them true, then uses generative AI to paint back the empty corners that straightening leaves behind, so you keep a clean, complete frame instead of cropping your shot. Everything happens at your photo's original resolution, and your iPhone's Display P3 color and native HDR gain map survive the whole way through — unlike editors that quietly flatten to sRGB. Beyond perspective, Keystone can generatively expand a shot to a new aspect ratio, upscale it, or reimagine it in a new style — all saved back as full-quality HEIF.
See it
Straighten the shot. Keep the whole frame.
More than perspective
A full AI editing suite
Perspective is where Keystone starts, not where it stops. Expand a scene beyond its edges, reimagine it in a new style, or dial in the color by hand — always at full resolution, always with HDR intact.
How it works
Three steps to a straighter shot
Straighten
Add your photo. Keystone finds the vanishing lines and levels the verticals — or fine-tune the corners, keystone, rotation and bow by hand.
AI fills the corners
Straightening leaves empty edges. Generative AI paints them back in seamlessly, at your photo's full resolution.
Save, full quality
Export as HEIF at native size with Display P3 and HDR intact — or keep going with expand, upscale and recreate.
Features
Built for real photos
Perspective & keystone fix
Correct converging verticals in architecture, real-estate and street photos — auto-detect or fine-tune by hand.
Corner fill at full resolution
Generative AI paints the empty corners left by straightening — no downscaling, no soft seams.
Generative expand
Reframe to a new aspect ratio and let AI extend the scene believably beyond its edges.
Upscale & recreate
Boost resolution and detail, or reimagine your shot in a whole new style from a prompt.
Display P3 + native HDR
Preserves your photo's wide-gamut color and HDR gain map end to end, not flattened to sRGB.
Keeps your originals intact
Native HEIC/HEIF in and out, with EXIF and location preserved and files saved in the same format.
FAQ
Questions, answered
What does Keystone Photo Studio do?
It's an iPhone photo editor for architecture and street photography. It detects the converging vanishing lines in a photo and straightens leaning buildings, then uses generative AI to fill the empty corners that straightening leaves behind — at full resolution — so you keep a clean, complete frame. It can also generatively expand a shot to a new aspect ratio, upscale it, reimagine it in a new style, and fine-tune it with pro color tools.
Is it free, and do I need an account?
Keystone is free to download and you can start editing right away with no account. Optional subscriptions unlock more AI edits and are billed monthly or yearly through your Apple ID, cancellable anytime.
What is the AI corner fill?
When you straighten a photo, correcting the perspective leaves empty triangular gaps at the edges. Instead of cropping them away, Keystone uses generative AI to paint those corners back in seamlessly at full resolution, so your composition stays intact.
Does it keep HDR and full resolution?
Yes. Unlike editors that flatten to sRGB, Keystone preserves your iPhone's wide-gamut Display P3 color and native HDR gain map end to end, and saves as HEIF at the photo's native resolution.
What else can it do besides fixing perspective?
It can generatively expand a photo beyond its edges to a new aspect ratio, upscale for more resolution and detail, reimagine a shot in an entirely new style with AI Recreate, and fine-tune exposure, contrast, saturation and color with a full adjustment studio and a real histogram.
Does it work on iPad?
Keystone Photo Studio is an iPhone app on the App Store and runs on iPad in iPhone-compatibility mode.
How do I cancel a subscription?
Subscriptions are managed through your Apple ID: open Settings, tap your name, tap Subscriptions, choose Keystone Photo Studio and cancel. You keep access until the end of the billing period.
Straighten your next shot — and keep every pixel.
Free to start · no account required
Download on the App StoreLegal & documents
Support & contact
Questions, feedback, or account/data requests — visit support or email support@vlodkodesign.com.