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Errors when trying to import the OpenCV framework into an iOS project

asked 2012-09-10 13:25:23 -0600

zenberg gravatar image

I downloaded the official version of iOS framework from and then created a simple view-based Xcode project and added the opencv2.framework in the build phases menu.

After that I imported the opencv2.framework as:

#ifdef __cplusplus
#import <OpenCV/opencv2/opencv.hpp>

into the *.pch file.

I have this function:

static void testOpenCV
    cv::Mat m, gray;

When I ran the build - it showed me this error:

~/projects/xcode/openCV_ex/openCV_ex/ViewController.m:45:8: Expected expression

When I try to include the OpenCV framework before any definitions in my .pch file like this:

#import <opencv2/opencv.hpp>
#import <Availability.h>

I get this error:

~/Downloads/opencv2.framework/Versions/A/Headers/video/background_segm.hpp:48:1: Unknown type name 'namespace'

Can you please help me to find a solution to this problem?

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answered 2012-09-11 08:35:12 -0600

AlexanderShishkov gravatar image

Do you change type of your project to Objective-C++ in project options: Apple LLVM compiler 3.1 -> Compile Sources As?

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I chose the option "Objective C++" in my Apple LLVM compiler 4.0 -> "Compile Sources As" and now it works! Thank you very much!

I am not sure if it is correct to post this question here, but in AppCode it still gives me an error that says that it can't resolve "cv::Mat". Can you please help with this one as well?

zenberg gravatar imagezenberg ( 2012-09-11 10:57:40 -0600 )edit

Could you add more detailed description of the problem, maybe with code sample and log of the error? It is better, if you do it as new question.

AlexanderShishkov gravatar imageAlexanderShishkov ( 2012-09-11 13:16:20 -0600 )edit

There is no error in the compiling time. It actually looks like an AppCode Editor issue and I decided to post the question on their official forum:

zenberg gravatar imagezenberg ( 2012-09-12 20:50:42 -0600 )edit

answered 2012-09-14 00:54:59 -0600

hkaraoguz gravatar image


Your ViewController.m file should be renamed as in order to use OpenCV or any other C++ code inside that file.

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It worked. Thank you very much!

zenberg gravatar imagezenberg ( 2012-09-14 13:16:44 -0600 )edit

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Asked: 2012-09-10 13:25:23 -0600

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Last updated: Sep 14 '12