The best way to improve Urdu Nastaliq OCR is to improve the image you give it: large, sharp, straight text on a clean background, with Urdu chosen as the language. Nastaliq is harder to read than printed English, so no setting makes it perfect, but a good scan in the OCR PDF tool can turn a page of errors into a draft that needs only light correction.
This guide explains why Nastaliq is difficult, then gives you the changes that make the biggest difference, in order of importance.
Why Nastaliq is hard for OCR
Understanding the problem helps you see which fixes matter.
- Words slope. In Nastaliq each word starts high on the right and flows down to the left. There is no single flat baseline for the software to follow.
- Letters overlap. The end of one word can sit above or below the start of the next, so the gaps between words are not clear vertical spaces.
- Shapes change. The same letter looks different depending on what it joins to. There are far more shapes to recognise than in a Latin alphabet.
- Dots decide meaning. Many letters share one body and differ only in the number and position of dots. A speck of dust or a lost dot changes the word.
Because of all this, Nastaliq needs more detail in the image than English does. A photo that is good enough for an English page can be too rough for Urdu.
Check that you really need OCR
Before working on scan quality, try selecting a word in your PDF. If the words highlight, the file is digital and already holds text, so OCR may be unnecessary. Our guide to the difference between a scanned PDF and a digital PDF shows how to check.
Eight ways to get better Urdu Nastaliq OCR results
1. Make the text bigger in the image
This is the most useful change. Move the camera closer, or scan at a higher resolution on a flatbed scanner. Thin strokes and dots need enough pixels to survive. If a page has small print, photograph it in two halves instead of one wide shot.
2. Use even, bright light
Shadows turn into dark patches that hide dots. Daylight from a window is ideal. Keep your hand and phone from casting a shadow, and turn off the flash on glossy paper.
3. Keep the page straight and flat
Tilted lines are a serious problem for a script that already slopes. Hold the camera directly above the page. For books, press the page flat so lines near the spine do not curve.
4. Scan with a proper scanner tool
The Camera Scanner detects the page edges automatically, lets you adjust the corners by hand and corrects the perspective. That gives OCR a flat rectangle of text instead of a slanted photo with the table in the background.
5. Choose the filter with care
Grayscale is a safe choice for most printed pages. Black and white can make clean print very crisp, but on faint or thin print it may erase dots and fine strokes. If a black and white scan gives worse text, scan again in grayscale or color and compare.
6. Select Urdu, not Arabic
The two languages share a script but not the same letters or word patterns. Always choose Urdu for Urdu text. The language data downloads the first time you use it.
7. Fix page direction first
A sideways or upside down page will not be read correctly. If your scanned PDF has turned pages, straighten them with Rotate PDF and save before running OCR.
8. Work with one column at a time
Newspapers and magazines put several columns on a page. When columns are close together, lines from two columns can be read as one. Crop or photograph each column on its own.
Step by step: a clean scan and OCR run
- Place the page on a flat, plain surface in good light.
- Open the Camera Scanner and allow the browser to use your camera when it asks.
- Capture the page, then check the detected edges and drag the corners if needed.
- Apply the grayscale filter and add more pages if the document has several.
- Save the PDF, then open it in the OCR PDF tool.
- Select Urdu and start the recognition. Keep the tab open until it finishes.
- Copy the text or download the .txt file, then proofread it against the page.
Test one page before doing a whole book. If the test page is poor, change the scan, not the OCR.
Source quality: what to expect
| Source | Typical result | Advice |
|---|---|---|
| Modern printed book, clean page | Usable draft with some corrections | Scan close and straight |
| Newspaper | Mixed, columns cause trouble | One column per image |
| Old or faded photocopy | Many errors | Try grayscale, consider retyping |
| Screenshot of typed Urdu | Often the best result | Zoom in before the screenshot |
| Handwriting or calligraphy | Poor | Type it by hand |
Proofreading checklist for Nastaliq text
Even a good run needs a careful read. Check these points:
- Letters that differ only by dots, which are the most common mistake.
- Words that were joined together or split in two.
- Names of people and places, which the software cannot guess from context.
- Numbers, dates and amounts, especially when Urdu and English digits are mixed.
- Missing short words at the start or end of a line.
- Punctuation that jumped to the wrong side of the line.
Once the text is corrected, you may want a neat copy to share. Our guide on how to make a PDF with Urdu text shows how to turn the clean text into a properly aligned document.
A note on ID cards and forms
OCR is for reading text, and it struggles with small print on cards with patterned backgrounds. If you only need a clear copy of your identity card to print or submit, you do not need OCR at all. See how to put CNIC front and back on one page as a PDF instead.
Frequently asked questions
Why is Urdu OCR less accurate than English OCR?
Nastaliq words slope, overlap and change shape as letters join, and dots carry a lot of meaning. English print has separate letters on a flat line, which is much simpler to recognise.
Is Naskh style Urdu easier to OCR than Nastaliq?
Generally yes. Naskh style type sits on a flat baseline with clearer spacing, so it tends to be read with fewer errors.
Does a higher resolution always improve Urdu OCR?
Up to a point. Bigger, sharper text helps a lot. Beyond that, a huge image only slows processing. A blurred photo does not improve by being enlarged afterwards.
Can I run OCR on a long Urdu book in one go?
You can, but the work is done on your device, so long files take time. Splitting the book into chapters makes each run shorter and easier to proofread.
Good Nastaliq results come from good scans more than anything else. Fix the light, size and angle, then run your pages through the OCR PDF tool with Urdu selected and proofread what comes out.