QuadCropper vs PersCrop

This app contains a Photos extension to crop and deskew rectangles in a photo. Since the rectangles may be skewed by perspective, the cropping tool allows individual placement of the four corners of the 2D quadrilateral -- and then deskews the contained rectangle. This is useful for business cards or slides or book covers or the like which have been photographed at an angle. The app mimics the functionality of the Photos extension and can access the Photos library or the camera to get an image. One can also crop the image from any file. Unless the image is retrieved from the Photos library, the app will store the cropped image to a user-selected file. Corners can be nudged by tapping on the corner circles. The corner will move by a pixel in the direction of the quadrant of the circle that was tapped on.

PersCrop flattens a photo shot at an angle into a straight-on rectangle. Drag the four corners onto your subject and the photo is warped square using a true projective transform — the same maths a scanner's dewarp uses — not a rotation or a stretch. Everything runs on your phone; no photo ever leaves the device. Photograph a whiteboard, a page, a painting or a shop sign and the angle you stood at is baked in: edges lean, corners stretch, the rectangle isn't a rectangle. That is the problem PersCrop was built to solve. Around it sits a small set of tools for the rest of what you do to a photo before posting it. PERSPECTIVE CROP — straighten a photo taken at an angle • Drag four corners onto any four-sided subject: documents, whiteboards, artwork, posters, shop signs • A real homography warp removes the keystone distortion and returns a proper rectangle • Live preview updates as you drag, so you see the result before exporting • Output resolution follows the shape you selected, so detail is kept • Export as PNG, JPEG or WebP NO CROP — fit the whole photo to any aspect ratio • Post the entire photo, with nothing chopped off by a square or vertical frame • Pad to any ratio with a solid color, a gradient, or a blurred copy of the photo itself • Square 1:1, Portrait 4:5, Story 9:16, Classic 4:3, Wide 16:9, plus 3:2, 2:3, A4 paper, 21:9 cinema and 3:1 banner COLLAGE — several photos in one frame • Column, row, grid and diagonal layouts that adapt as photos are added or removed • Adjustable gaps, corner rounding and background color • Pinch and drag inside a cell to position each photo exactly PANORAMA CROP — one wide photo, one seamless carousel • Slice a wide shot into equal panels that line up as the carousel swipes • Choose the panel count and which part of the photo the panels cover GRID CROP — turn an image into a profile mosaic • Cut one image into tiles that rebuild it across your profile grid • Three tiles wide, as many rows as you want • Tiles export in posting order, so the mosaic assembles correctly BUILT FOR PHONES • GPU-accelerated rendering, so previews move with your finger instead of lagging behind it • Light and dark themes that follow your system setting • Save straight to your photo library, or share to any app • Batch save several results in one run PRIVATE BY DESIGN Every crop, warp and export happens on your device. PersCrop has no account, no sign-in, no analytics profile and no server to send photos to. Photo library access is used only to read the picture you pick and to save what you make. It works with no connection at all. WHAT PERSCROP IS NOT It is not a document scanner: there is no OCR, no text recognition and no multi-page PDF export. It straightens and exports images. PERSCROP PRO The core tools are free. Pro is a one-time purchase — no subscription and no recurring charge — and unlocks all tools, the full set of aspect ratios and editing options, and unlimited batch saving. Questions or feedback? Get in touch and we'll answer.