Using a phone to scan and print (copy) documents is ideal for convenience, portability, and quick tasks, making it a versatile and practical choice for many users. In this article, we are going to build a web app to scan and print a document on a mobile phone. The following...

Exchangeable image file format (officially Exif) is a standard that specifies formats for images, sound, and ancillary tags used by digital cameras (including smartphones). It contains metadata like camera parameters, image dimensions, and image orientation. Most camera sensors have a shape where its width is larger than the height. If...

Sometimes, we may need to merge multiple images into a single PDF file. For example, we scan the front side and the back side of an ID card and want to store them in a single PDF file. In this article, we are going to talk about how to build...

Image cropping is a common image processing task where we only need a potion of an image. In most cases, we make a rectangular selection box for cropping. But for cases like document scanning, we need to make a polygonal selection box. Perspective transformation is needed to normalize the document....

Dynamsoft Document Normalizer is an SDK to detect the boundary of documents and runs perspective transformation to get a normalized document image. In this article, we are going to build an iOS document scanner using Dynamsoft Document Normalizer and AVFoundation. A demo video of the final result: The scanning process:...