I'm trying to use **libpng** for reading data from image file in my c++ project, making on xcode and have some problems to include it.

So, I've make the next steps:

1. download **libpng** sources from <http://libpng.sourceforge.net> (version 1.6.29) and unarchive
2. download xcode project folder from here <https://github.com/IGRSoft/libpng-xcode-project> and put it into **./projects** folder
3. open libpng.xcodeproj and make build. As a result I have */Users/admin/Library/Developer/Xcode/DerivedData/libpng-efgdtopqjltxorcwlnlvdirxqclm/Build/Products/Debug/**libpng.framework***
4. I copied this file to my xcode project folder
5. Add this file to **Project->General->Linked Frameworks and Libraries**

Then, when I'm trying to compile project, I have an error:

`ld: framework not found libpng
clang: error: linker command failed with exit code 1 (use -v to see invocation)`

What I'm doing wrong or what step was missed?

I'm new in xcode so be patient and give a detailed answer, please.