Perspective Crop (Photographed Document)
When a document or whiteboard is photographed at an angle, it appears distorted as a trapezoid. Place the 4 corners of the document on the image below: the tool calculates the perspective transformation needed to straighten it into a perfectly rectangular shape.
How It Works
When a rectangular document is photographed from an angle, its parallel sides seem to converge (perspective effect). By indicating where its 4 corners actually are in the photo, the tool calculates a perspective transformation (a homography) that maps this distorted quadrilateral to a perfect rectangle, then resamples every pixel of the result by bilinear interpolation from the source image.
In what order should I click on the corners?
Always in the same order: top-left, top-right, bottom-right, then bottom-left of the document as it appears in the photo (even if it is tilted). A different order would produce a flipped or incorrectly distorted image.
Why might the result look slightly blurry in places?
The area farthest from the camera in the original image naturally contains fewer pixels per unit of real surface area of the document: once enlarged by perspective correction, this area appears slightly less sharp than the part closest to the lens. This is an inherent effect of the original photo, not a limitation of the tool.
100% local processing: the perspective correction is calculated pixel by pixel directly in your browser — your document is never sent to a server.