Convert PDF to TIFF Issue

Hello,
I converted a pdf with 8 pages to tiff,But I found that pages 3 to 8 were incorrect。I have uploaded my source code for your reference,and the source pdf file is ./bin/Debug/intput.pdf.
Pleasetake a look at my source code and see if I did anything wrong,Thanks a lot.
Note:Due to attachment size limitations,i have delete the file ‘Aspose.pdf.dll’,and the version of the dll i used is 18.1.0.0.if you want to run my demo application,please add the dll and a license to …/debug/bin
AsposeDemo.7z (7.5 MB)

@HomerWu
You are setting the brightness which is making it look dark. Using Aspose.PDF for .NET 21.6 version, the output is good if you comment out the brightness setting. output.zip (713.4 KB)

Hello,
Thanks for your reply.
As you said,i have tried change the value of brightness.and i found if the value is 0.1-0.4,those pages are black,and when the value is 0.5,then those pages are white;when the value is 0.6-1.0,those pages are black again.
So,1.which value you used? 2. must i use the version 21.6?

Hello,

After i use your latest version(21.6),i can get the converted tiff as same as you sent to me.but i can not use our old license to use aspose.pdf.dll.i think this is a issue you already fixed after version 18.1.0.0,could you please tell me which version you fixed it?as our license just allows free upgrades until 26 Mar 2019。

@HomerWu

This improvement can be a result of some other bug fix and we may not specifically trace it. We suggest you to upgrade to latest version. However, you can take a look at the Release Notes for reference.