c++ - Compiling OpenCV code on a 64-bit mac

Question

I recently inherited some OpenCV code. I installed openCV on my mac, built in in XCode, and then compiled and successfully ran my first openCV "hello world"-ish program.

Now I'm trying to run the code I was given, but I get errors that lead me to believe it's an issue with the original code being run on a 32-bit Windows system and mine being on a 64-bit Mac.

When I run the Makefile by entering "make"

CC = g++
CFLAGS =
LDFLAGS = -I/usr/local/include/opencv -lm -lopencv_core -lopencv_highgui -lopencv_video
ALL = vision

all: $(ALL)

vision: vision.o
    $(CC) $(LDFLAGS) -o $@ $^

vision.o: vision.cpp
    $(CC) $(LDFLAGS) -c $<

.PHONY: clean

clean:
    rm -rf *.o core* $(ALL)

I get the following output…

g++ -I/usr/local/include/opencv -lm -lopencv_core -lopencv_highgui -lopencv_video -o vision vision.o
Undefined symbols for architecture x86_64:
  "cv::equalizeHist(cv::Mat const&, cv::Mat&)", referenced from:
      _main in vision.o
  "cv::threshold(cv::Mat const&, cv::Mat&, double, double, int)", referenced from:
      _main in vision.o

ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status
make: *** [vision] Error 1

I'm confused; does this mean my install of OpenCV is wrong, the code (those methods specifically) needs to be changed, or something else entirely?

Note: When I comment out the problem methods from the vision.cpp code, everything compiles just fine.

Answer 1

Add opencv_imgprocto your LDFLAGS:

LDFLAGS = -I/usr/local/include/opencv -lm -lopencv_core -lopencv_highgui -lopencv_video -lopencv_imgproc