How it works

What happens between the shutter and the PDF. Every step runs on your iPhone or iPad.

Before the shot

While you aim, Nescanner finds the page in the live camera image and outlines it. Two hints help you get a good shot:

• Level the phone. A strongly tilted phone blurs the far edge of the page. When the tilt is too large, the app shows the angle and waits until you level the phone.
• Move back. When the page touches the edge of the frame, part of it would be cut off. The app asks you to step back until the whole page fits.

The camera focuses on the middle of the page, not on its nearest point, so a slightly tilted page stays sharp from top to bottom.

Batch mode

For books and stacks of pages, tap the batch button next to the shutter. Hold the phone over the page: as soon as the page is in the frame and still, the shutter fires by itself. Then the app waits until you turn the page, so the same page is never taken twice. Tap the button again to go back to single shots.

The shot

Nescanner captures in RAW, the unprocessed data from the camera sensor. That gives the app full control over light, colour and sharpness. On iPhone models with Apple ProRAW it uses ProRAW. On other models, in dim light, it takes three frames in one go and averages them to remove grain. Devices without RAW use the camera’s processed photo, convert it back to linear light and run it through the same steps.

Two modes

Document is for text: printed pages, contracts, receipts, forms. The paper becomes white and the text crisp and dark.

Picture is for covers, artwork and magazines. The page is straightened and evenly lit, but its colours and tones stay as they are.

Processing, step by step

1. Straightening. The four corners of the page turn the shot into a flat rectangle. On a book, the app measures how the lines of text bend towards the spine and flattens the page along them. Either way the image is resampled exactly once: every extra resampling softens thin strokes.
2. Noise. Sensor grain is removed without smearing fine strokes, separately for brightness and colour.
3. Sharpness (Document). The slight blur of the lens is measured on the page and reversed where it helps the text.
4. Even light. The app estimates how the light falls across the paper and evens it out. Shadows from your hand or the phone disappear. Photos and colour areas on the page are recognised and left alone.
5. Tone (Document). Paper becomes white and text dark, while photos keep their shades instead of turning into flat black. Colour text, highlights and tinted panels keep their colour.
6. Orientation. The app reads the direction of the text and turns the page the right way up.
7. Text. Text on the page is recognised on the device and added to the PDF as an invisible layer. You can search and copy it in any PDF viewer.

What it never does

• It does not turn the page into pure black and white. Grey, colour and photos survive.
• It does not redraw or invent letters. What you see in the scan was on the paper.
• It does not send anything anywhere. There is no server to send to.

Export

In the document screen, the export button builds one PDF of all pages and opens the share sheet: Save to Files, AirDrop, Mail or any other app. In the corners screen you can export just that page as JPEG or PDF.

Quality is set in the ••• menu of the document screen:

• Low: 150 dpi, the smallest file, good for email.
• Medium: 200 dpi, a balance for everyday use.
• High: full resolution for archiving and printing.

Files are named by date and time, for example Nescanner_20261001143015.pdf.

Where your pages live

Pages of the document in progress are kept in the app’s own folder and cleared the next time Nescanner starts. Export what you need before you close the app. If you turn on Keep RAW captures in the ••• menu, the original camera captures stay in the app’s folder, visible in the Files app.

Languages

Nescanner speaks 33 languages. It follows the language of your device, or the one you pick for Nescanner in Settings → Apps → Nescanner → Language.

On iPad

Nescanner runs natively on iPad. In landscape the camera controls sit at the side, as in the Camera app, and in a wide window the list of pages and the corners editor open side by side.

Free and Pro

Every feature is free, at the same quality for everyone. Without a subscription you can export up to 30 pages a day; the count resets at midnight, and exporting the same page again on the same day does not count twice. Nescanner Pro removes the limit and changes nothing else. See the Terms of Use.