How to compile my c program which uses opencv - opencv

I have started learning OpenCV.
I am working on linux.
From their documentation page I was able to compile this
http://docs.opencv.org/doc/tutorials/introduction/linux_gcc_cmake/linux_gcc_cmake.html#linux-gcc-usage
However after that I got lost in trying to declare a new mat and it's constructors.
SO I decided to go with this book http://www.amazon.com/Learning-OpenCV-Computer-Vision-Library/dp/0596516134
However I am not able to compile the very first program from this book.
The program is here :
#include "highgui.h"
int main(int argc, char** argv)
{
IplImage* img = cvLoadImage (argv[1]);
cvNamedWindow("Example1", CV_WINODW_AUTOSIZE);
cvShowImage("Example1",img);
cvWaitKey(0);
cvReleaseImage(&img);
cvDestroyWindow("Example1");
}
I saved this in a file named load.c
Then I created a CMakeLists.txt file and put this in it :
project( load )
find_package( OpenCV REQUIRED )
add_executable( load load )
target_link_libraries( load ${OpenCV_LIBS} )
when running "cmake ." from terminal it is succesful. But when I am running "make" it gives me this error :
Scanning dependencies of target load
[100%] Building C object CMakeFiles/load.dir/load.o
/home/ishan/load/load.c: In function ‘main’:
/home/ishan/load/load.c:4:2: error: too few arguments to function ‘cvLoadImage’
/usr/local/include/opencv2/highgui/highgui_c.h:212:18: note: declared here
/home/ishan/load/load.c:5:28: error: ‘CV_WINODW_AUTOSIZE’ undeclared (first use in this function)
/home/ishan/load/load.c:5:28: note: each undeclared identifier is reported only once for each function it appears in
make[2]: *** [CMakeFiles/load.dir/load.o] Error 1
make[1]: *** [CMakeFiles/load.dir/all] Error 2
make: *** [all] Error 2
I think it is because this example in the book is for OpenCV 1.x while I am currently running 2.4.3, however I believe there must be a way to run this program and the subsequent program that are in the book.
I think the problem lies with linking the header files properly.
I would like to first read from the book and using reference from documentation and then switch to documentation fully. But for now I wish to learn from the book as learning from the book is far easier to me than documentation. Plus I bought this book for approx 3000 INR and got it just today, I don't want to see it go to waste. I want to learn from it.
Please help me out.

CV_WINODW_AUTOSIZE is mispelled. The correct constant is CV_WINDOW_AUTOSIZE
cvLoadImage (argv[1]); should be cvLoadImage (argv[1], 1); (for loading a color image) because the C standard does not support default arguments.
By the way, if you're using OpenCV 2.0+, I recommend learning the C++ API. It's a lot less convoluted than the C API and performance is comparable.

Related

How to setup jpeglib with MS Visual C++ 2010 Express

I try to use the well known "jpeglib" now available in version 9.
Overview: I am a programming starter in C using MS Visual C++ 2010 Express and read a C-book finally. My goal is to compress a RGB(.bmp)-file into JPEG. So I downloaded the jpeglib (v9), read all the install and so on *.txt-files. It was possible to compile the C-files to get cjpeg.exe, djpeg.exe, jpeg.lib and so on.
After this success I tried to use the example.c to get deeper into the jpeg and to control the compression. -> It did not work. Then I tried to use the jpeglib included in OpenCV. Same non working result, while the OpenCV code samples are compiled successfully.
I googled lots of samples, problem solutions and tips how to use jpeglib. Most helpful information I found here. But in the result I was still not able to compile my own jpeg-tool or example.c (rewriting the write_JPEG_file() function ).
Question: What in the basics could be wrong, when every other programmer just uses #include "jpeglib.h" in their codes to run the jpeg functions successfully? For me including this file seems not to be enough. Because of that I have to ask you and to relaunch a one year old Question that also did not helped solving my probs. I can not give you a specific error message because of multiple attempts to solve those issues.
Here is my current MS-VC++2010 config for using OpenCV 2.4.6:
C/C++ -> General -> Additional Include Directories:
C:\opencv\build\include
C:\opencv\build\include\opencv
C:\opencv\build\include\opencv2
C:\opencv\include
C:\opencv\include\opencv
C:\opencv\include\opencv2
C:\opencv\3rdparty\libjpeg
Linker -> General -> Additional Library Directories:
C:\opencv\build\x86\vc10\lib
Linker -> Input -> Additional Dependencies:
opencv_core246d.lib
opencv_imgproc246d.lib
opencv_highgui246d.lib
opencv_ml246d.lib
opencv_video246d.lib
opencv_features2d246d.lib
opencv_calib3d246d.lib
opencv_objdetect246d.lib
opencv_contrib246d.lib
opencv_legacy246d.lib
opencv_flann246d.lib
jpeg.lib [this I added into C:\opencv\build\x86\vc10\lib]
At last some threads I have already read:
Compressing IplImage to JPEG using libjpeg in OpenCV - 1
Compressing IplImage to JPEG using libjpeg in OpenCV - 2
Need help in reading JPEG file using libjpeg
how can i use jpeg_mem_src, jpeg_mem_dest in libjpeg-turbo?
If there is something missing you want to know I will do my best to add this information!
EDIT - Some error messages:
1>jpeg_coder.obj : error LNK2001: unresolved external symbol ""unsigned char * image_buffer" (?image_buffer##3PAEA)".
1>jpeg_coder.obj : error LNK2001: unresolved external symbol ""int image_height" (?image_height##3HA)".
1>jpeg_coder.obj : error LNK2001: unresolved external symbol """int image_width" (?image_width##3HA)".
First symbol should be typedefed in jpeglib.h as JSAMPLE FAR *JSAMPROW,
second and third are defined in rdjpgcom.c as unsigned int image_height, image_width;
Maybe, with a lot of luck, I figured out what is need to be done to get jpeglib running. In the current state I have to check and double check whether my problem solution is correct or not. At this point thank you very much for your attention for my issues. As soon as I am sure with the solution I will post it.
Problem Solution: I did not setup OpenCV correctly for using jpeglib. The mistake I made was to link the wrong *.lib-file. The proper file for linking is libjpegd.lib. Too bad that jpeglib v6.2 is included in OpenCV 2.4.6 instead of v9. The hint to add HAVE_JPEG to use jpeglib functions inside OpenCV I ignored completely. For now the problem is solved.
Problem Solution: I did not setup OpenCV correctly for using jpeglib. The mistake I made was to link the wrong *.lib-file.
The proper file for linking is libjpegd.lib.
Too bad that jpeglib v6.2 is included in OpenCV 2.4.6 instead of v9. The hint to add HAVE_JPEG to use jpeglib functions inside OpenCV I ignored completely. Thanks to all who tried solving this issue. For now the problem is solved.

CAP_PROP_FRAME_WIDTH undeclared in 'How to build applications with OpenCV inside the Microsoft Visual Studio' sample code

I'm following the instructions in How to build applications with OpenCV inside the Microsoft Visual Studio but I'm getting errors from the sample code:
error C2065: 'CAP_PROP_FRAME_WIDTH' : undeclared identifier
error C2065: 'CAP_PROP_FRAME_HEIGHT' : undeclared identifier
error C2065: 'CAP_PROP_FRAME_COUNT' : undeclared identifier
I think the identifiers that are undeclared should be declared in highgui so why am I not getting them despite the demo code's #include <opencv2/highgui/highgui.hpp>?
Here are the steps I have taken.
I've unpacked the OpenCV (Version 2.4.6) files into C:\OpenCV, run setx -m OPENCV_DIR C:\OpenCV\Build\x64\vc11 from an elevated command prompt and added %OPENCV_DIR%\bin to my path (following instructions in Installation in Windows). Then using the Property pages (View -> Property Pages or Shift-F4) set to 'All Configurations'
I've added $(OPENCV_DIR)\..\..\include to my C/C++ Additional Include Directories
I've added $(OPENCV_DIR)\lib to the linker Additional Library Directories
I've cut-an-paste the directory listing of the lib files in C:\OpenCV\build\x64\vc11\lib into my input Additional Dependencies
I've copied the sample code from the article into a new C++ console app (with ATL). I had to change one line in the template code from int _tmain(int argc, _TCHAR* argv[]) to int _tmain(int argc, char* argv[])
I think the identifiers that are undeclared should be (are) declared in highgui so why am I not getting them despite the demo code's #include <opencv2/highgui/highgui.hpp>?
Other people having similar issues getting this sample code working in the How to build applications with OpenCV inside the Microsoft Visual Studio note seem to fall over with link errors (e.g. here and here) but I am getting past the linker.
========== EDIT ==========
There appear to be more insurmountable difficulties with the sample code. It is documented as a simple example to load and display an image whose path is supplied as the sole argument to main, while the code listing itself is video code requiring four command line arguments (i.e. it first checks and stops if argc != 5). I've submitted a documentation bug. I think the sample code listing should have been be taken from this: https://github.com/Itseez/opencv/blob/master/samples/cpp/tutorial_code/introduction/display_image/display_image.cpp
Try with CV_CAP_ or cv::CAP_... It looks like there were some changes aiming to improve consistency of constants in OpenCV...
I am using the opencv 2.4.6 and this has helped me do the trick
change CAP_PROP_FRAME_WIDTH into CV_CAP_PROP_FRAME_WIDTH
change CAP_PROP_FRAME_HEIGHT into CV_CAP_PROP_FRAME_HEIGHT
change CAP_PROP_FRAME_COUNT into CV_CAP_PROP_FRAME_COUNT
and similarly if there are any other cap prop keywords into cv cap prop keywords
try this.

Cannot link a minimal Lua program

I have the following trivial Lua program which I copied from the book Programming In Lua
#include <stdio.h>
#include <lua.h>
#include <lauxlib.h>
#include <lualib.h>
int main (void)
{
char buff[256];
int error;
lua_State *L = luaL_newstate(); /* opens Lua */
luaL_openlibs(L); /* opens the standard libraries */
while (fgets(buff, sizeof(buff), stdin) != NULL)
{
error = luaL_loadbuffer(L, buff, strlen(buff), "line") ||
lua_pcall(L, 0, 0, 0);
if (error)
{
fprintf(stderr, "%s", lua_tostring(L, -1));
lua_pop(L, 1); /* pop error message from the stack */
}
}
lua_close(L);
return 0;
}
my environment is cywin
my make file looks like this:
CC=gcc
INCLUDE='-I/home/xyz/c_drive/Program Files/Lua/5.1/include'
LINKFLAGS='-L/home/xyz/c_drive/Program Files/Lua/5.1/lib' -llua51
li.o:li.c
$(CC) $(INCLUDE) -c li.c
main:li.o
$(CC) -o main $(LINKFLAGS) li.o
clean:
rm *.o
rm main
My /home/xyz/c_drive/Program Files/Lua/5.1/lib directory contains lua5.1.dll lua5.1.lib lua51.dll and lua51.lib
Trying to build my main target I am getting the following errors:
li.o:li.c:(.text+0x35): undefined reference to `_luaL_newstate'
li.o:li.c:(.text+0x49): undefined reference to `_luaL_openlibs'
li.o:li.c:(.text+0xaf): undefined reference to `_luaL_loadbuffer'
li.o:li.c:(.text+0xd9): undefined reference to `_lua_pcall'
li.o:li.c:(.text+0x120): undefined reference to `_lua_tolstring'
li.o:li.c:(.text+0x154): undefined reference to `_lua_settop'
li.o:li.c:(.text+0x167): undefined reference to `_lua_close'
Any ideas about what I might be doing wrong here?
The problem is that you have named the libraries on the link command line before the object files that require them. The linker loads modules from left to right on the command line. At the point on the line where you name -llua51, no undefined symbols that could be satisfied by that library are known. Then you name li.o, which does have unknown symbols.
Some Unix-like environments don't treat this as an error because part of the link process is deferred to the program load when reference to .so files are satisfied. But Cygwin, MinGW, and Windows in general must treat this as an error because DLLs work quite differently from .so files.
The solution is to put -llua51 after all the .o files on your link line.
Edit: Incidentally, it appears you are linking against the Lua for Windows distribution, but building with GCC under Cygwin. You will want to use Dependency Walker to make sure that your program does not depend on the Cygwin runtime, and that it does depend on the same C runtime as the lua51.dll from Lua for Windows. IIRC, that will be the runtime for the previous version of Visual Studio. It is possible to make GCC link against that, but you will need to be using the MinGW port (which you can use from Cygwin), and link against a couple of specific libraries to get that version. I'm away from my usual PC, or I'd quote an exact link line. (I believe you need -lmoldname -lmsvcr80 or something like that, as the last items on the link line.)
It will cause mysterious and very hard to diagnose problems if more than one C runtime library is in use. The easy answer is to use the same one as your preferred Lua DLL. Another alternative is that the Lua Binaries project has pre-compiled Lua DLLs for a wide array of C toolchains on Windows. If you need a Lua application that understands the Cygwin environment, you will want one that is built by GCC for Cygwin and not the Lua for Windows flavor. Lua Binaries will be your friend, or you can build Lua your self from source.
The names in the Lua API do not have those leading underscores. Try compiling with -fno-leading-underscore.

trying to run COBOL .exe using C++ program

I'm still learning how to program but I have a simple question. I have the following code for running an executable COBOL program through C++, but I am getting COBOL errors: 251 and 410
#include <iostream>
#include <windows.h>
using namespace std;
int main(){
system("C:\\rmcobol\\runcobol.exe SOLOCAJA.COB c=windows.cfg L=WOWRT.DLL");
cout << "\n";
system("pause");
return 0;
}
I assume there must be a very simple reason for this, but I am clueless so far. Any help would be highly appreciated.
Error 410 is a "configuration file not found" error based on Apendix A of the user guide. Are you sure your windows.cfg file is in the directory you're running your code in?
Failing that, error 251 states "Incorrect runtime command" and all the samples I can find have an uppercase C. So maybe change your C program to use to:
system("C:\\rmcobol\\runcobol.exe SOLOCAJA.COB C=WINDOWS.CFG L=WOWRT.DLL");
and see if that fixes it (a long shot, I know, but I've seen stranger things than that).
Based on update:
I tried changing the c to a C on the C=WINDOWS.CFG, ran it in C++ and directly on the Command Line, no change. I am still looking into the reasons behind this, and I read through tek-tips.com/viewthread.cfm?qid=1119251&page=5 but I couldn't use any of that info. Any extra tips would be gold at this point. THANKS!
A couple of questions:
Has it ever worked in this environment?
Is it failing on both cmdline and within C (just want to clarify)?
Does windows.cfg actually exist in the current directory when you run it?
Are you running it in a directory with spaces (like My Documents)?
Other than that, maybe post the windows.cfg file, though the error seems pretty explicit that it's config file not found rather than error in config file.

Simple OpenCV problem

Why I try to run the following OpenCV program, it shows the following error :
ERROR:
test_1.exe - Application Error
The application failed to initialize properly (0x80000003).
Click on OK to terminate the application.
CODE:
#include "cv.h"
#include "highgui.h"
int main()
{
IplImage *img = cvLoadImage("C:\\face.bmp");
cvSetImageROI(img, cvRect(100,100, 100, 100));
cvAddS(img, cvScalar(50), img);
cvResetImageROI(img);
cvShowImage("Test", img);
cvWaitKey(0);
return 0;
}
When i press F5(im using vs2008express), the program encounters a break point...i have attached a picture...dont know, whether, it will help or not.
Error Snapshot Link
It is not that, only this program is producing this error, but also any kind of image manipulation funciton containing (OpenCV)program is resulting in this sitution.
Such as : cvSmooth
one last thing, it there any dedicated OpenCV forum or sth like that?
I am an administrator.So, yes, ive the permission.
a version mismatch.
sorry, i didn't get it?Version mismatch with what?
But, i have found the error using dependency walker.
Warning: At least one module has an unresolved import due to a missing export
function in a delay-load dependent module.
and also found that, it is a common problem, and found some info in the FAQ of DW...
Why am I seeing a lot of applications where MPR.DLL shows up in red under
SHLWAPI.DLL because it is missing a function named WNetRestoreConnectionA?
I also get a "Warning: At least one module has an unresolved import due to
a missing export function in a delay-load dependent module" message.
Function name : WNetRestoreConnectionA
But there is no guideline about how to solve it. Though, they say, it is not a problem.
i googled a little and found a suggestion.It says,
Turn off your compilers setting to assume you are programming for Win9x.
(I just lost which setting but it is not that difficult, use a #define...)
But i have no idea, how to do that in Visual Studio 2008 express.
Any suggestion how to solve it...
This usually indicates a problem with a dll; either you don't have permission, or a version is mismatched. Try running as Administrator to see if it is a permissions problem. If that doesn't help, try using the Dependency Walker.

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