C# Methods of Converting PDF into Images

My friend works in a software production company. Recently, the company arranged for him a task and asked him to deliver a DLL file to realize the function of converting PDF to image c#. It is best to be able to master all the source code. And he needs to deliver a PDF converter DLL made by a third party. He asked me to help him with this. I studied for a long time and went to various forums, but still failed. Finally, I found a lot of useful PDF to text converter tools and would like to share them with you here.
 
1. CnetSDK.PDFtoImage.Converter.dll, a third-party DLL, can perfectly convert PDF into images. The images transferred from the trial version have a watermark. The official version can be purchased, and the price is the lowest among all third-party DLLs as I know. Its PDF to image conversion speed is fast, and the definition is high. The size and DPI of the image/picture can be set freely. You can first download its free trial version to test its function on its official website. The download package contains Demo and user documentation. This solution was also the last solution I adopted. After it was given to the company, everything was perfect and works well.
DLL detail can be found on this page.
http://www.cnetsdk.com/net-pdf-to-image-converter-sdk
 
2. iTextSharp.dll, C# open source PDF processing tool, can operate PDF at will, and can extract text and pictures in PDF, but cannot directly convert PDF into pictures.
 
3. PdfSharp.dll, the C# open source PDF processing tool, can manipulate PDF at will, and can also extract pictures from PDF, but cannot directly convert PDF into pictures.
The above two open source C# tools can handle PDF documents very well, but they do not meet the requirement of directly converting PDF to IMAGE, but can be reserved for other PDF-related projects in the future.
 
4. ImageMagick, an open source PDF processing tool in C language, can convert PDF into images because our project is a C# project, so I haven't tested too much in C language.
 
5. Acrobat.dll, an interface officially provided by Adobe, can convert PDF into images.
This method requires Adobe Acrobat X Pro to be installed. Copy the Acrobat.dll file from the installation file to use it.
After all, this solution is an interface officially provided by Adobe. Its conversion efficiency is faster than other DLLs and is more reliable. However, the downside is that you need to install Adobe's related programs, which occupy large hard disk space and the computer configuration is low. Sometimes the operation freezes.
 
6. Ghostscript, a free tool, can convert PDF to image. It seems that many people on the Internet will use this method, but I don't think it is very useful.
 
7. O2S.Components.PDFRender4NET.dll, a third-party DLL, can convert PDF to image. There will be a row of red watermarks in the upper left corner of the trial version of the dll. The official version needs to be purchased and the price is not low.
 
8. XpdfRasterizer.dll, a third-party DLL, can convert PDF to image.
This tool must pay attention to Regsvr32 registration, otherwise, the conversion will fail.
 
9. abcpdf.dll, a third-party DLL, can convert PDF to image, but abcpdf needs to be installed, so it is not too convenient to use.
 
Finally, to summarize, there are actually many third-party DLLs, so I won't list them all. I personally think that CnetSDK.PDFtoImage.Converter.dll is still the best to use, because it is the most efficient, stable, and cheapest, and it is easy to convert multiple PDFs to images at the same time. However, sometimes the program crashes when using other DLLs.
 
Secondly, I recommend Acrobat.dll. After all, it is Adobe's official. The code is relatively simple, easy to use, and the efficiency is good, but the shortcomings are also obvious, as described above.
 
You can choose from the above solutions according to the advantages and disadvantages of each tool and your actual needs.