Mobile document scanning has become a baseline feature for productivity apps — think expense reports captured from receipts, signed contracts photographed in a meeting room, or ID documents registered at a service counter. Building such a feature from scratch, handling perspective correction, edge detection, and multi-format export, is a significant...

In the previous article, we talked about how to convert an image to black and white with a threshold. It may not work well with images having uneven lighting in tasks like barcode reading. For example, if we convert the following QR code with shadow to black and white with...

Handheld camera devices play a big part in the document scanning process as they are more portable, powerful and affordable. However, different from using a document scanner, using a camera imposes challenges like complex backgrounds, variations in light, and perspective distortions. Thus, it is necessary to use a document scanning...

Image compressing on the browser is a useful operation. It can improve the uploading performance and save the storage. In this article, we are going to talk about how to compress an image with JavaScript using the Dynamsoft Document Viewer SDK. We can compress an image by changing the following...

When digitizing documents, we may accidentally scan a document image twice. Finding the duplicate images manually is painstaking. In this article, we are going to use JavaScript to detect duplicate document images automatically. What you’ll build: A JavaScript library that uses Tesseract.js OCR and Levenshtein distance to automatically detect and...

Filters are commonly used to adjust the rendering of images. We can use it to make images sharper, remove unwanted objects, or adjust the color tone. In this article, we are going to build a JavaScript library to perform various image filters. It can be used together with Dynamsoft Document...

Whether we scan documents via document scanners or cameras, we may end up getting document images with bad quality. In this article, we are going to talk about how to evaluate the quality of scanned document images so that we can recapture the document to get a better image. A...

A black-and-white binary image consists of pixels that can have one of exactly two colors: black and white. Converting an image to black and white has some usages: File size reduction: a 1-bit binary image requires less data for storage than a 24-bit color image. Image processing: many image processing...

Grayscale images are composed exclusively of shades of gray. They are commonly stored with 8 bits per sampled pixel, which allows 256 different intensities to be recorded. Converting an image to grayscale has some usages: File size reduction: an 8-bit grayscale image often requires less data for storage than a...

Sometimes, we may need to flip a media element in a web app. For example, we may need to flip a video element streaming from a camera to match what we actually see or correct scanned document images that are flipped. What you’ll build: A browser-based tool that flips or...

In a document-scanning web app, image resizing is useful as it can correct the proportion of scanned documents and increase the DPI of document images to meet printing requirements. In this article, we are going to talk about how to resize an image with JavaScript. One way is using Canvas...

Sometimes, we may need to rotate an image on a web page, like showing a loading animation. In a document-scanning web app, we need to rotate skewed document images or document images scanned in the wrong direction. What you’ll build: An HTML5 page that rotates images using three approaches —...

Scanning documents into a digital form can help companies save physical space, improve data retrieval, reduce costs, improve collaboration, etc. Sometimes, we may come across very large scanned document files or files scanned with a low visual quality. In this article, we are going to talk about aspects related to...

Scanned documents often contain skewed or crooked images. They do not look good and are not friendly for OCR. In this article, we are going to use OpenCV and Python to deskew scanned documents based on text lines. What you’ll build: A Python script that detects and corrects skew in...