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Handling Distorted Scans

Taking a photo of a printed report introduces perspective distortion. The axes are no longer orthogonal, and parallel lines converge.

1. Identify the Bounding Box

Find the four corners of the chart area. These are typically where the axes meet or the outer border of the grid.

2. Apply Perspective Correction

Use a tool (like Photoshop, or our upcoming built-in de-warper) to map those four corners back to a perfect rectangle. This mathematically un-does the camera angle.

Distortion Type	Severity	Fix Method
Rotation (Scan skew)	Low	Affine transform (handled by Graphshot)
Perspective (Photo angle)	High	Homography matrix / 4-point warp
Barrel (Lens warp)	Medium	Lens correction profile