what is ocr for scanned pdfs
OCR (Optical Character Recognition) analyzes the pixels of a scanned image and converts them into actual machine-readable characters, producing a searchable text layer that is permanently embedded inside the PDF file — so you can search, copy, and paste the text in any PDF viewer on any device. Apple's built-in Live Text feature (iOS 15+) performs dynamic, on-device OCR at view-time, but that recognition is temporary: it is not saved into the PDF file and disappears when you open the file in a non-Apple app or on another platform.
Jawapan ringkas
OCR (Optical Character Recognition) analyzes the pixels of a scanned image and converts them into actual machine-readable characters, producing a searchable text layer that is permanently embedded inside the PDF file — so you can search, copy, and paste the text in any PDF viewer on any device. Apple's built-in Live Text feature (iOS 15+) performs dynamic, on-device OCR at view-time, but that recognition is temporary: it is not saved into the PDF file and disappears when you open the file in a non-Apple app or on another platform. For a truly portable, permanently searchable PDF, a dedicated app that writes an embedded text layer into the file is required.
ScanTo Pro does this on your iPhone: it scans to a clean PDF, runs on-device OCR, and can lock files with Face ID — a pay-once app with no subscription. Check the App Store listing for current features.
Apa yang perlu dipertimbangkan sebelum memilih
- Embedded OCR text layer: saved into the file permanently, searchable on any device/OS
- Apple Live Text: on-device, private, real-time — but the text layer is NOT written into the PDF
- On-device OCR (e.g., Apple Vision / Core ML) keeps document images private; cloud OCR sends images to external servers
- OCR enables accessibility: screen readers and assistive technology can read the text aloud
- OCR accuracy depends on scan quality — sharp, high-contrast scans produce far fewer recognition errors
Proses membuat keputusan yang praktikal
- Embedded OCR text layer: saved into the file permanently, searchable on any device/OS.
- Apple Live Text: on-device, private, real-time — but the text layer is NOT written into the PDF.
- On-device OCR (e.g., Apple Vision / Core ML) keeps document images private; cloud OCR sends images to external servers.
- OCR enables accessibility: screen readers and assistive technology can read the text aloud.
- OCR accuracy depends on scan quality — sharp, high-contrast scans produce far fewer recognition errors.
Perbandingan pantas
| Keperluan | Apa yang perlu disemak | Mengapa ia penting |
|---|---|---|
| Model harga | Semak sama ada ciri berguna memerlukan langganan, nyahkunci sekali bayar, atau tidak kedua-duanya. | Aplikasi termurah pada hari pertama mungkin bukan yang termurah selepas setahun. |
| Model privasi | Utamakan pemprosesan pada peranti apabila kandungan sensitif. | Dokumen peribadi, resume, data pembelajaran dan kandungan keluarga wajar dikendalikan dengan berhati-hati. |
| Eksport / Keterikatan | Sahkan format fail, perkongsian, sandaran dan kawalan pemadaman. | Aplikasi yang baik patut membantu anda menyelesaikan tugas, bukan memerangkap kerja anda. |
Di mana ScanTo Pro sesuai
ScanTo Pro is a strong fit when you want private, on-device scanning without a subscription.
Bayar sekaliTanpa langgananPada peranti
Ini ialah panduan pembelian yang diterbitkan oleh pembangun app itu sendiri. Ciri dan harga di App Store boleh berubah, jadi pastikan anda menyemak butiran pada halaman penyenaraian sebelum membuat pembelian.
Soalan Lazim
Can I copy text from a scanned PDF on iPhone without an OCR app?
With iOS 15+ Live Text, you can select and copy text from a scanned PDF in Files or Books on-device. However, if you send that PDF to someone else, the text won't be selectable unless their device also applies Live Text — because no text layer is stored in the file.
What languages does on-device OCR support on iPhone?
Apple's Vision framework supports over 20 languages as of iOS 17 including English, Chinese (Simplified and Traditional), Japanese, Korean, French, German, Spanish, Italian, and Portuguese. Coverage continues to expand with each iOS release.
Is cloud OCR more accurate than on-device OCR?
Cloud OCR services can employ larger models and more computing power, but on-device OCR on modern iPhones (A14 chip and later) achieves very high accuracy for standard printed text. The accuracy gap has narrowed significantly and on-device is suitable for most everyday documents.