what it does
PerspectiveFix corrects perspective distortion in photographs. You draw lines along edges that should be straight, and the app computes a correction so those edges become truly vertical or horizontal. The corrected image is then cropped and saved.
Everything happens on your device. No images are uploaded anywhere.
loading an image
Tap Load Image at the top of the menu (☰) to open the image picker. You can choose from your Photos library, take a new photo, or browse Files. TIFF gives the best quality output; JPEG and PNG also work.
drawing reference lines
In Draw mode, drag your finger along a straight edge in the photo — a door frame, wall edge, window, horizon. The line type is set automatically: steep lines become Vertical (gold), shallow lines become Horizontal (blue).
You can draw up to 2 vertical and 2 horizontal lines. More lines give a more accurate correction. Even a single line straightens the image on that axis.
The 10×10 grid helps you judge alignment as you work.
editing lines
Switch to Edit mode to fine-tune line positions. Endpoint circles appear at each end of every line — drag them to reposition. Edit mode is only available after at least one line is drawn.
Use ↩ Undo and ↪ Redo in the menu to step through line history. ✕ Clear removes all lines after a confirmation.
warp anchor
A small gold ⚓ marker sits at the center of the photo by default — this is the one point the correction guarantees stays at its original scale; everything else is stretched or compressed relative to it.
Drag it anywhere in the photo to move that fixed point, if the default center isn't the part of the image you most want to look right. Double-tap the marker to snap it back to center.
Available in both Draw and Edit mode, same as reference lines.
applying the correction
Tap Apply in the toolbar. The app computes a full-resolution perspective warp based on your reference lines. This may take a moment on large images.
You'll enter the crop stage, where the corrected image is shown with a crop box.
cropping
The crop box is auto-placed at the largest rectangle that fits inside the corrected image with no blank edges. A rule-of-thirds grid and center crosshair help with composition.
Drag inside the box to reposition it. Drag a corner circle to resize. Tap ☰ to change the aspect ratio or output format.
Blank areas outside the crop (from the warp) appear as a checkerboard for TIFF/PNG output, or black for JPEG.
stretch
Tap Stretch (Crop stage) if the corrected image's proportions still look wrong — too tall/narrow or too short/wide — after correction. This is different from the Crop ratio selector, which only changes the shape of the crop box, not the image itself.
Pick H or V on the switch to choose which dimension to adjust, then drag the slider — center is no change, one side shortens/narrows, the other lengthens/widens. Confirm with the checkmark, or ✕ to cancel. The crop box resets to fit afterward.
saving
Tap Save. A sheet appears — tap Share… to open the iOS share sheet. From there you can save to Photos, Files, AirDrop, Messages, and more. To save to Photos, tap the share sheet's "Save Image" option.
After saving, tap Load Image in the menu to process the next photo.
output formats
TIFF — lossless with transparency. Best quality, largest file. Recommended for further editing in apps like Affinity Designer or Photoshop.
PNG — lossless with transparency. Smaller than TIFF, no quality loss.
JPEG — compressed. Smallest file. Quality slider 70–100. Good for sharing or when file size matters.
gestures
| one-finger drag | draw a line (Draw mode) or move an endpoint (Edit mode) |
| two-finger drag | pan the image |
| pinch | zoom in or out |
settings
Tap ⚙ Settings next to the menu button to adjust toolbar size, contrast, workspace background, and the "keep lines" batch processing option.
privacy
PerspectiveFix runs entirely on your device. No images, lines, or settings are ever sent to a server. The app works with no internet connection after the initial page load.
