Free Tool Desk

Document Photo Cleaner (Straighten & Remove Shadows)

Straighten a photographed page: drag its four corners to flatten the perspective, fix the tilt, lift shadows and sharpen contrast. Before and after view, in your browser.

Free to use No sign-up required Nothing is uploaded

A phone photo of a page is tilted, wider at the near edge, and dimmed by your own shadow. This tool fixes those three problems in the order a scanner app would: you place four handles on the corners of the page and it flattens the perspective, it straightens the text lines, and it evens out the lighting so the paper looks white and the text dark.

Everything runs in your browser and the photo is not uploaded. The result is cleaner and easier to read or OCR, but it is a processed photo, not a scan, and the page says so.

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Overview

About Document Photo Cleaner

1. Perspective. The tool first looks for a large light region on a darker surface and puts the four corner handles on it; you drag them onto the real corners. The quadrilateral is mapped to a rectangle with a projective transform and bilinear sampling, so a trapezoid becomes a straight page. The output size follows the average length of the page\'s opposite sides, so the aspect ratio is preserved.

2. Tilt. After flattening, the angle of the text lines is estimated with a projection profile: the image is turned through small angles and the angle at which the rows of ink are most sharply separated is taken as the tilt. It is applied automatically when the evidence is strong, and a fine-rotation slider lets you correct it by hand.

3. Lighting. The paper brightness under the text is estimated by removing strokes narrower than a window and smoothing, and every pixel is divided by it, so shadows and uneven light are lifted towards one white level. Contrast is then stretched. The shadow and contrast sliders set how much; the output can stay in colour, become grey, or become black and white with a hard threshold.

Preview and save. The original with its handles and the result are shown side by side (stacked on small screens). Changes appear as you move controls, using a smaller preview; the saved file is made at up to 2400 pixels on the long side, as PNG or JPEG.

Compatibility

Supported Formats

JPEG, PNG and WebP photos up to 30 MB, 12,000 pixels on a side and 40 megapixels (decided by the content, not the name). Output: PNG or JPEG up to 2400 pixels on the long side.

Guide

How to Use Document Photo Cleaner

  1. Choose a photo of a page, preferably on a darker surface with all four corners visible.
  2. Drag the four blue handles onto the corners of the page (or press "Use the whole photo").
  3. Leave perspective and tilt correction on, and adjust shadow reduction, contrast and colour mode while watching the result.
  4. Download the cleaned image as PNG or JPEG.

Highlights

Features

  • Four-corner perspective Drag handles onto the page corners; the page is flattened to a rectangle without changing its proportions.
  • Automatic deskew Estimates the tilt of text lines and corrects it, with a manual fine-rotation slider.
  • Shadow and contrast Divides out uneven lighting, then stretches contrast; colour, grey or black and white.
  • Before and after See the original with its corners and the live result together.
  • Private by design The photo is processed in your browser and never uploaded.

Applications

Use Cases

  • Making a phone photo of a form, certificate or letter readable before sending it
  • Preparing a page photo for OCR, for example with Bangla OCR
  • Removing the shadow of your hand or phone from a page photo
  • Straightening a photographed receipt, notice board or whiteboard page
  • Turning several photos into clean pages to combine into a PDF with Image to PDF

Good to Know

Limitations

This helps a photo look like a scan; it does not replace a scanner. Automatic corner detection is a starting guess that works best for a light page on a darker, plain surface, so check the four corners. Curved pages (an open book), folds, strong glare, partial shadows with sharp edges and pages that are only partly in the frame cannot be flattened properly.

Stronger contrast and black and white make text sharper but can wash out pale handwriting, stamps, highlights and photographs on the page, and small print can be lost; compare with the original. Resampling softens the picture slightly. Do not use the output where an original document is required.

This tool runs entirely in your browser — your file is never uploaded to our servers. See our Privacy Policy for full details.

Support

Frequently Asked Questions

Is my photo uploaded?

No. The correction runs in your browser. Nothing is sent to our server, and file names are not sent to analytics.

The corners were found in the wrong place. What now?

Drag the handles onto the corners yourself, or press "Use the whole photo" if the page already fills the picture. Automatic detection is only a starting point.

Why is part of my page still dark?

Shadows with sharp edges, glare and folds are hard to remove. Raise shadow reduction, or retake the photo in even light with the phone directly above the page.

Can it flatten the curve of a book page?

No. It corrects perspective (a flat page seen at an angle), not curved or folded paper.

Will black and white make the text easier to read?

Often, for printed text. It can erase pale ink, stamps and photos, so look at the original too.

Can I use the result as an official copy?

Only if the recipient accepts a processed photo. It is not a certified scan, and the original document is what counts.

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