Graphics

Microsoft Cognitive Services offers us computer vision services to describe images and to detect printed or handwritten text. Text recognition provides interesting scenarios like cloud based OCR or providing automated translations for texts on images. This blog post focuses on recognizing printed text using Azure Computer Vision API.

ASP.NET Core introduces Node services that allow applications to run Node scripts on server. We can send data from controller action to Node script and get back some output we can use in view. This blog post shows how to use Node services to render d3.js charts on server-side to PNG files.

One quick code note to make during building my Azure Cognitive Services demo application. I needed a way how to convert colors of System.Drawing to hex strings that I can use in views. Here is my simple and elegant solution.

In my previous posting about WebImage helper I introduced how to use WebImage for different image manipulations. In this posting I will show you how to build simple online image editor using WebImage helper.

Cropping images in ASP.NET is easy task to do if you use right tools. In this posting I will introduce how to crop images using Jcrop and System.Drawing namespace classes. What we are building is simple and user-friendly image cropping interface that also demonstrates some simple features of Jcrop. Believe me, your users will love it!

In one of my current projects I needed something that takes image uploaded by user and converts it to avatar image. There is requirement for avatar images: they must be 32x32 pixel squares. Here is my solution.

One of my readers asked for example about my image resizing routine. Here you can find example and also some notes about my code design solution.

ASP.NET provides us with System.Drawing namespace where we can find classes we can use to manipulate with images. There are many people out there who mistakenly think thatImage.GetThumbnailImage is best choice for image resizing. You can easily create crappy images if you follow the code examples in previously pointed article. In this post I will show you how to resize images without negative side effects.

In this example we will use simple color recalculation method to grayscale images. For each pixel on image we will calculate "average color" that we write back on image. Average color is sum of current color's red, green and blue channels integer value divided by three. This value is assigned to all three channels for current pixel.