Below is a sample to guide you how to convert PDF to JPG/JPEG image in VB .NET.
Besides load local PDF, loading PDF stream is supported. Following example shows how to convert PDF first page to Jpeg image with wanted size using Visual Basic.NET code.
Another article, guiding to specify the image size using DPI property is supported, please see "How to customize images from PDF pages using vb.net". Do contact us if you have any other questions, pqScan is always ready to help.