why i receive the following error?

This a part of code i use in my project:

addpath('src');
addpath('net');

opts.idx_gpus = 1; % 0: cpu 1: gpu

%%1) Install MatConvNet
opts.install.cuda_path = '/usr/local/cuda-8.0';  %set to your cuda folder path
opts.install.matconvnet_path = 'matconvnet-1.0-beta24/matlab/vl_setupnn.m';
untar('http://www.vlfeat.org/matconvnet/download/matconvnet-1.0-beta24.tar.gz') ;
run(opts.install.matconvnet_path) ;

if opts.idx_gpus > 0
    vl_compilenn('enableGpu', true,'cudaRoot', opts.install.cuda_path, 'cudaMethod', 'nvcc') ;
else 
    vl_compilenn('enableGpu', false);
end    

 *when i run it on gpu server (R2015) i have the following error*
"Error using mex
/home/Mohammed/dcgan-matconvnet-master/matconvnet-1.0-beta24/matlab/src/bits/imp                                                                                                                                                  l/imread_libjpeg.cpp:22:21:
fatal error: jpeglib.h: No such file or directory
compilation terminated.
Error in vl_compilenn>mex_compile (line 529)
mex(mopts{:}) ;
Error in vl_compilenn (line 490)
    mex_compile(opts, srcs{i}, objfile, flags.mexcc) ;
Error in main_start_dcgan (line 16)
    vl_compilenn('enableGpu', true,'cudaRoot', opts.install.cuda_path,
    'cudaMethod', 'nvcc') ;"

[Joss Knight]

MatConvNet has its own forums for user issues, you might want to try there:

https://groups.google.com/forum/#!forum/matconvnet

https://github.com/vlfeat/matconvnet/issues

Answer 1

[Joss Knight]

In MatConvNet's own installation documentation, which I found by typing "MatConvNet jpeglib" into Google, it specifically mentions that libJPEG is required:

"Remark: The 'vl_imreadjpeg' tool uses an external image library to load images. In macOS and Windows, the default is to use the system libraries (Quartz and GDI+ respectively), so this dependency is immaterial. In Linux, this tool requires the LibJPEG library and the corresponding development files to be installed in the system. If needed, the ImageLibraryCompileFlags and ImageLibraryLinkFlags options can be used to adjust the compiler and linker flags to match a specific library installation. It is also possible to use the EnableImreadJpeg option of vl_compilenn to turn off this feature."