How to extract text from images in Flutter?
Use OCR to extract text from images in Flutter

by Ans Ali
Mobile App Developer, Numla

In today's digital era, extracting text from images has become an essential feature in numerous applications. Whether it's digitising documents, performing text recognition for translation, or enabling data extraction from receipts, Optical Character Recognition (OCR) technology has revolutionised these capabilities. In this article, we will dive into the process of extracting text from images using Flutter, Google's open-source UI toolkit. By exploring the underlying mechanisms and available tools, we'll gain a deeper understanding of how we can accomplish this task in Flutter.

Extract text from images using OCR workflow

The process of extracting text from images in Flutter involves a series of steps. Let's examine the workflow:

1. Image acquisition

The first step is to acquire the image containing the desired text. This can be done through various methods, such as capturing an image using the device's camera or selecting an image from the gallery. Flutter provides packages like `camera` and `image_picker` that facilitate image acquisition within your application.

2. Preprocessing

Once we have obtained the image, it often requires preprocessing to enhance its quality and improve OCR accuracy. Preprocessing techniques may involve resizing, cropping, adjusting contrast or brightness, and applying filters to optimise the image for OCR. Flutter offers image manipulation libraries like `image` and `flutter_image_compress` that enable you to perform these preprocessing tasks.

3. Utilising OCR libraries

Flutter provides several OCR libraries that integrate OCR capabilities into your application. One popular choice is the Firebase ML Kit OCR, which offers a wide range of features for text recognition. To utilise the Firebase ML Kit OCR in your Flutter project, you need to set up a Firebase project, configure it with your Flutter app, and add the necessary dependencies.

4. OCR processing

With the OCR library integrated into your project, you can process the preprocessed image to extract text. The OCR library uses advanced machine learning and computer vision algorithms to analyse the image and recognise the characters present. It breaks down the image into text blocks, lines, and individual characters, providing you with structured data that represents the extracted text.

5. Post-processing and utilisation

Once the text has been extracted, you can perform post-processing tasks on the extracted data as per your application's requirements. This may involve cleaning up the text, removing unnecessary characters or spaces, or applying additional language-specific processing. Finally, you can utilise the extracted text within your Flutter application for various purposes, such as displaying it to the user, storing it in a database, or performing further analysis.


The ability to extract text from images using Flutter opens a world of possibilities for developers. By understanding the workflow involved in the process, from image acquisition to OCR processing and text utilisation, you can seamlessly integrate OCR capabilities into your Flutter applications. Whether you need to scan documents, automate data extraction, or enhance user experiences, Flutter provides the tools and libraries necessary to accomplish these tasks. Explore the available OCR libraries, such as the Firebase ML Kit OCR, and leverage their power to unlock the potential of text extraction from images in your Flutter projects.


The accuracy of text extraction from images in Flutter can vary depending on factors such as image quality, text complexity, and the underlying OCR (Optical Character Recognition) technology used. While modern OCR algorithms have improved accuracy, challenges may still arise when dealing with handwritten text, distorted images, or text in unusual fonts.

Implementing text extraction from images in Flutter apps may have performance implications, particularly in terms of processing time and resource usage. The computational complexity of OCR algorithms and the size of images being processed can impact app responsiveness and overall performance. Developers may need to optimise their code and consider asynchronous processing to mitigate any performance bottlenecks.

How does the extracted text handle different languages, fonts, and text orientations?

The ability of the extracted text to handle different languages, fonts, and orientations largely depends on the OCR engine's capabilities. Modern OCR technologies typically support various languages and fonts, including non-Latin scripts and handwritten text. However, developers should still test their text extraction solution with diverse samples to ensure robustness across various linguistic and typographic contexts.

Enhance Your App's Visual Intelligence with Google ML Kit Face Detection
Improve app functionality with face detection capabilities