Image Processor is an easy to use and extend processing library written in C#. Its fluent API makes common imaging tasks very simple to perform. Methods include; Resize, Rotate, Rounded Corners, Flip, Crop, Watermark, Filter, Saturation, Brightness, Contrast, Quality, Format...
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Создаешь консольный проект в VS
Через диспетчер пакетов добавляешь ImageProcessor
Компилируешь
В папке проекта будет библиотека.