mac 安装opencv homebrew安装

0 Homebrew是啥？

“Homebrew installs the stuff you need that Apple didn’t.——Homebrew 使 OS X 更完整”。

Homebrew的官网[1]（多语言版本）简单明了地介绍了如何安装和使用这个工具，并提供了自己的Wiki。

1 安装Homebrew 

brew的安装很简单，使用一条ruby命令即可，Mac系统上已经默认安装了ruby。

gerryyang@mba:bin$ruby --version
ruby 2.0.0p247 (2013-06-27 revision 41674) [universal.x86_64-darwin13]

关于安装brew的详细说明可以参考其github上的wiki说明[2]：

"
Installation

The suggested and easiest way to install Homebrew is on the homepage. We don’t duplicate it here because it is asecurity risk to list it on a user-editable wiki.

The standard script installs Homebrew to /usr/local so that you don’t need sudo when youbrew install. It is acareful script, it can be run even if you have stuff installed to/usr/local already. It tells you exactly what it will do before itdoes it too. And you have to confirm everything it will do before itstarts.

There are other ways to install Homebrew which provide you with moreflexibility. They are listed below the requirements.

"

1. gerryyang@mba:~$ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)"  
2. It appears Homebrew is already installed. If your intent is to reinstall you  
3. should do the following before running this installer again:  
4.   
5.     rm -rf /usr/local/Cellar /usr/local/.git && brew cleanup  

由于我的系统上已经安装过brew，因此再次执行安装命令会提示我brew已经存在。

2 Homebrew的用法 

查看brew的具体用法：

1. gerryyang@mba:~$brew  
2. Example usage:  
3.   brew [info | home | options ] [FORMULA...]  
4.   brew install FORMULA...  
5.   brew uninstall FORMULA...  
6.   brew search [foo]  
7.   brew list [FORMULA...]  
8.   brew update  
9.   brew upgrade [FORMULA...]  
10.   brew pin/unpin [FORMULA...]  
11.   
12. Troubleshooting:  
13.   brew doctor  
14.   brew install -vd FORMULA  
15.   brew [--env | --config]  
16.   
17. Brewing:  
18.   brew create [URL [--no-fetch]]  
19.   brew edit [FORMULA...]  
20.   open https://github.com/Homebrew/homebrew/wiki/Formula-Cookbook  
21.   
22. Further help:  
23.   man brew  
24.   brew home  
25.   
26. gerryyang@mba:~$  

在安装好brew后，只需要一条命令就可以安装OpenCV了：

1	brew install opencv

通常情况下这样做就应该会安装成功，但我在公司和家里面的电脑尝试的时候，brew都会报一些错误，我遇到的都是一些小问题，按照brew的提示信息，解决掉相应的问题即可。

安装成功后，你应该可以在“/usr/local/include”目录下找到名为opencv和opencv2的目录，这里面是OpenCV相关的头文件。你也可以在“/usr/local/lib”目录下找到许多以libopencv_开头的.dylib文件，这些是OpenCV的链接库文件。

这里有一个技巧，因为 /usr 目录在对话框中默认不是可见的，可以按快捷键 command + shift + G，在弹出的“前往文件夹”对话框中输入 /usr/local/lib ，即可跳转到目标文件夹。如下图所示：

下一步是我自己试出来的，对于Lion操作系统，你需要在Build Settings中，将“C++ Language Dialect”设置成C++11，将“C++ Standard Library”设置成libstdc++ ，如下图所示。个人感觉是由于XCode默认设置的GNU++11、libc++与OpenCV库有一些兼容性问题，我在更改该设置前老是出现编译错误。后续版本在Montain Lion系统中解决了这个问题，不用进行这一步了。

把上面的设置都做好后，就可以在需要的使用OpenCV库的地方，加上opencv的头文件引用即可：

1	#import "opencv2/opencv.hpp"

注意，如果你的源文件扩展名是.m的，你还需要改成.mm，这样编译器才知道你将会在该文件混合使用C++语言和Objective-C语言。

OpenCV处理图象需要的格式是cv::Mat类，而MacOS的图象格式默认是NSImage，所以你需要知道如何在cv::Mat与NSImage之前相互转换。如下是一个NSImage的Addition，你肯定会需要它的。该代码来自stackoverflow上的这个贴子。

NSImage+OpenCV.h 文件：

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

// // NSImage+OpenCV.h // // Created by TangQiao on 12-10-26. // #import <Foundation/Foundation.h> #import "opencv2/opencv.hpp" @interface NSImage (OpenCV) +(NSImage*)imageWithCVMat:(const cv::Mat&)cvMat; -(id)initWithCVMat:(const cv::Mat&)cvMat; @property(nonatomic, readonly) cv::Mat CVMat; @property(nonatomic, readonly) cv::Mat CVGrayscaleMat; @end

NSImage+OpenCV.mm文件：

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131

// // NSImage+OpenCV.mm // // Created by TangQiao on 12-10-26. // #import "NSImage+OpenCV.h" static void ProviderReleaseDataNOP(void *info, const void *data, size_t size) { return; } @implementation NSImage (OpenCV) -(CGImageRef)CGImage { CGContextRef bitmapCtx = CGBitmapContextCreate(NULL/*data - pass NULL to let CG allocate the memory*/, [self size].width, [self size].height, 8 /*bitsPerComponent*/, 0 /*bytesPerRow - CG will calculate it for you if it's allocating the data. This might get padded out a bit for better alignment*/, [[NSColorSpace genericRGBColorSpace] CGColorSpace], kCGBitmapByteOrder32Host|kCGImageAlphaPremultipliedFirst); [NSGraphicsContext saveGraphicsState]; [NSGraphicsContext setCurrentContext:[NSGraphicsContext graphicsContextWithGraphicsPort:bitmapCtx flipped:NO]]; [self drawInRect:NSMakeRect(0,0, [self size].width, [self size].height) fromRect:NSZeroRect operation:NSCompositeCopy fraction:1.0]; [NSGraphicsContext restoreGraphicsState]; CGImageRef cgImage = CGBitmapContextCreateImage(bitmapCtx); CGContextRelease(bitmapCtx); return cgImage; } -(cv::Mat)CVMat { CGImageRef imageRef = [self CGImage]; CGColorSpaceRef colorSpace = CGImageGetColorSpace(imageRef); CGFloat cols = self.size.width; CGFloat rows = self.size.height; cv::Mat cvMat(rows, cols, CV_8UC4); // 8 bits per component, 4 channels CGContextRef contextRef = CGBitmapContextCreate(cvMat.data, // Pointer to backing data cols, // Width of bitmap rows, // Height of bitmap 8, // Bits per component cvMat.step[0], // Bytes per row colorSpace, // Colorspace kCGImageAlphaNoneSkipLast | kCGBitmapByteOrderDefault); // Bitmap info flags CGContextDrawImage(contextRef, CGRectMake(0, 0, cols, rows), imageRef); CGContextRelease(contextRef); CGImageRelease(imageRef); return cvMat; } -(cv::Mat)CVGrayscaleMat { CGImageRef imageRef = [self CGImage]; CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray(); CGFloat cols = self.size.width; CGFloat rows = self.size.height; cv::Mat cvMat = cv::Mat(rows, cols, CV_8UC1); // 8 bits per component, 1 channel CGContextRef contextRef = CGBitmapContextCreate(cvMat.data, // Pointer to backing data cols, // Width of bitmap rows, // Height of bitmap 8, // Bits per component cvMat.step[0], // Bytes per row colorSpace, // Colorspace kCGImageAlphaNone | kCGBitmapByteOrderDefault); // Bitmap info flags CGContextDrawImage(contextRef, CGRectMake(0, 0, cols, rows), imageRef); CGContextRelease(contextRef); CGColorSpaceRelease(colorSpace); CGImageRelease(imageRef); return cvMat; } + (NSImage *)imageWithCVMat:(const cv::Mat&)cvMat { return [[[NSImage alloc] initWithCVMat:cvMat] autorelease]; } - (id)initWithCVMat:(const cv::Mat&)cvMat { NSData *data = [NSData dataWithBytes:cvMat.data length:cvMat.elemSize() * cvMat.total()]; CGColorSpaceRef colorSpace; if (cvMat.elemSize() == 1) { colorSpace = CGColorSpaceCreateDeviceGray(); } else { colorSpace = CGColorSpaceCreateDeviceRGB(); } CGDataProviderRef provider = CGDataProviderCreateWithCFData((CFDataRef)data); CGImageRef imageRef = CGImageCreate(cvMat.cols, // Width cvMat.rows, // Height 8, // Bits per component 8 * cvMat.elemSize(), // Bits per pixel cvMat.step[0], // Bytes per row colorSpace, // Colorspace kCGImageAlphaNone | kCGBitmapByteOrderDefault, // Bitmap info flags provider, // CGDataProviderRef NULL, // Decode false, // Should interpolate kCGRenderingIntentDefault); // Intent NSBitmapImageRep *bitmapRep = [[NSBitmapImageRep alloc] initWithCGImage:imageRef]; NSImage *image = [[NSImage alloc] init]; [image addRepresentation:bitmapRep]; CGImageRelease(imageRef); CGDataProviderRelease(provider); CGColorSpaceRelease(colorSpace); return image; } @end

完成以上步骤后，恭喜你，你可以在源代码中自由地调用OpenCV的函数了。

3 Homebrew的有趣问题

下面关于Homebrew的一些常见问题[3]：

(1) 在OS X中找不到想要的软件，可以使用brew安装；

1. gerryyang@mba:~$brew install wget  
2. ==> Downloading http://ftpmirror.gnu.org/wget/wget-1.14.tar.gz  
3. ######################################################################## 100.0%  
4. ==> ./configure --prefix=/usr/local/Cellar/wget/1.14 --sysconfdir=/usr/local/etc  
5. ==> make install  
6. Warning: Could not link wget. Unlinking...  
7. Error: The `brew link` step did not complete successfully  
8. The formula built, but is not symlinked into /usr/local  
9. You can try again using `brew link wget'  
10.   
11. Possible conflicting files are:  
12. /usr/local/bin/wget  
13. /usr/local/share/man/man1/wget.1  
14. ==> Summary  
15. <span style="font: 13.0px Monaco">/usr/local/Cellar/wget/1.14: 8 files, 688K, built in 2.3 minutes</span>   

由于之前使用源码方式安装过wget，因此再用brew安装时会提示冲突的错误，因为/usr/locat/bin/wget已经存在。实际上，Homebrew 将软件包分装到单独的目录（/usr/local/Cellar），然后 symlink 到 /usr/local 中。 

(2) 如何更新本地已安装的package呢？

第一步：先更新brew：

brew update

1. gerryyang@mba:bin$brew update  
2. Already up-to-date.  

第二步：更新所有package：
brew upgarde

1. gerryyang@mba:bin$brew upgrade  
2. ==> Upgrading 1 outdated package, with result:  
3. wget 1.15  
4. ==> Upgrading wget  
5. ==> Installing wget dependency: openssl  
6. ==> Downloading https://downloads.sf.net/project/machomebrew/Bottles/openssl-1.0  
7. ######################################################################## 100.0%  
8. ==> Pouring openssl-1.0.1f.mavericks.bottle.tar.gz  
9. ==> Caveats  
10. This formula is keg-only, so it was not symlinked into /usr/local.  
11.   
12. Mac OS X already provides this software and installing another version in  
13. parallel can cause all kinds of trouble.  
14.   
15. The OpenSSL provided by OS X is too old for some software.  
16.   
17. Generally there are no consequences of this for you. If you build your  
18. own software and it requires this formula, you'll need to add to your  
19. build variables:  
20.   
21.     LDFLAGS:  -L/usr/local/opt/openssl/lib  
22.     CPPFLAGS: -I/usr/local/opt/openssl/include  
23.   
24. ==> security find-certificate -a -p /Library/Keychains/System.keychain > '/usr/l  
25. ==> security find-certificate -a -p /System/Library/Keychains/SystemRootCertific  
26. ==> mv -f /usr/local/etc/openssl/osx_cert.pem.tmp /usr/local/etc/openssl/osx_cer  
27. ==> Summary  
28. /usr/local/Cellar/openssl/1.0.1f: 429 files, 15M  
29. ==> Installing wget  
30. ==> Downloading http://ftpmirror.gnu.org/wget/wget-1.15.tar.gz  
31. ######################################################################## 100.0%  
32. ==> ./configure --prefix=/usr/local/Cellar/wget/1.15 --sysconfdir=/usr/local/etc --with-ssl=openssl --with-libssl-prefix=/usr/local/opt/openssl --disable-iri  
33. ==> make install  
34. Warning: Could not link wget. Unlinking...  
35. Error: The `brew link` step did not complete successfully  
36. The formula built, but is not symlinked into /usr/local  
37. You can try again using `brew link wget'  
38.   
39. Possible conflicting files are:  
40. /usr/local/bin/wget  
41. /usr/local/share/man/man1/wget.1  
42. ==> Summary  
43. /usr/local/Cellar/wget/1.15: 8 files, 700K, built in 73 seconds  
44. gerryyang@mba:bin$  

(3) 如何删除Homebrew？

If you installed to /usr/local then you can use the script in thisgist to uninstall — it will onlyremove Homebrew and the stuff Homebrew installed leaving anything elsein/usr/local alone.

Provided you haven’t put anything else in Homebrew’s prefix(brew --prefix), you can generally justrm -rf that directory. Thisis because Homebrew won’t touch files outside its prefix.

(4) Homebrew下载的package存放的路径在哪里？

1. gerryyang@mba:bin$brew --cache  
2. /Library/Caches/Homebrew  
3. gerryyang@mba:bin$ls /Library/Caches/Homebrew/  
4. Formula/                                wget-1.14.tar.gz  
5. coreutils-8.22.tar.xz                  wget-1.15.tar.gz  
6. openssl-1.0.1f.mavericks.bottle.tar.gz  xz-5.0.5.mavericks.bottle.2.tar.gz  
7. gerryyang@mba:bin$ls /Library/Caches/Homebrew/Formula/  
8. coreutils.brewing  openssl.brewing  wget.brewing  xz.brewing  
9.   
10. gerryyang@mba:bin$  

(5) 我可以安装自己的stuff在/usr/local吗？

Yes, brew is designed to not get in your way so you can use it how youlike.

Install your own stuff, but be aware that if you install commonlibraries, like libexpat yourself, it may cause trouble when trying tobuild certain Homebrew formula. As a resultbrew doctor will warn youabout this.

Thus it’s probably better to install your own stuff to the Cellar andthen brew link it. Like so:

$ cd foo-0.1
$ brew diy
./configure —prefix=/usr/local/Cellar/foo/0.1
$ ./configure —prefix=/usr/local/Cellar/foo/0.1
[snip]
$ make && make install
$ brew link foo
Linking /usr/local/Cellar/foo/0.1… 17 symlinks created

在我的环境上检测是这样的：

1. gerryyang@mba:bin$brew doctor  
2. Warning: Unbrewed dylibs were found in /usr/local/lib.  
3. If you didn't put them there on purpose they could cause problems when  
4. building Homebrew formulae, and may need to be deleted.  
5.   
6. Unexpected dylibs:  
7.     /usr/local/lib/libboost_atomic.dylib  
8.     /usr/local/lib/libboost_chrono.dylib  
9.     /usr/local/lib/libboost_context.dylib  
10.     /usr/local/lib/libboost_date_time.dylib  
11.     /usr/local/lib/libboost_filesystem.dylib  
12.     /usr/local/lib/libboost_graph.dylib  
13.     /usr/local/lib/libboost_iostreams.dylib  
14.     /usr/local/lib/libboost_locale.dylib  
15.     /usr/local/lib/libboost_log.dylib  
16.     /usr/local/lib/libboost_math_c99.dylib  
17.     /usr/local/lib/libboost_math_c99f.dylib  
18.     /usr/local/lib/libboost_math_c99l.dylib  
19.     /usr/local/lib/libboost_math_tr1.dylib  
20.     /usr/local/lib/libboost_math_tr1f.dylib  
21.     /usr/local/lib/libboost_math_tr1l.dylib  
22.     /usr/local/lib/libboost_prg_exec_monitor.dylib  
23.     /usr/local/lib/libboost_program_options.dylib  
24.     /usr/local/lib/libboost_python.dylib  
25.     /usr/local/lib/libboost_random.dylib  
26.     /usr/local/lib/libboost_regex.dylib  
27.     /usr/local/lib/libboost_serialization.dylib  
28.     /usr/local/lib/libboost_signals.dylib  
29.     /usr/local/lib/libboost_system.dylib  
30.     /usr/local/lib/libboost_thread.dylib  
31.     /usr/local/lib/libboost_timer.dylib  
32.     /usr/local/lib/libboost_unit_test_framework.dylib  
33.     /usr/local/lib/libboost_wave.dylib  
34.     /usr/local/lib/libboost_wserialization.dylib  
35.   
36. Warning: Unbrewed static libraries were found in /usr/local/lib.  
37. If you didn't put them there on purpose they could cause problems when  
38. building Homebrew formulae, and may need to be deleted.  
39.   
40. Unexpected static libraries:  
41.     /usr/local/lib/libboost_atomic.a  
42.     /usr/local/lib/libboost_chrono.a  
43.     /usr/local/lib/libboost_context.a  
44.     /usr/local/lib/libboost_coroutine.a  
45.     /usr/local/lib/libboost_date_time.a  
46.     /usr/local/lib/libboost_exception.a  
47.     /usr/local/lib/libboost_filesystem.a  
48.     /usr/local/lib/libboost_graph.a  
49.     /usr/local/lib/libboost_iostreams.a  
50.     /usr/local/lib/libboost_locale.a  
51.     /usr/local/lib/libboost_log.a  
52.     /usr/local/lib/libboost_math_c99.a  
53.     /usr/local/lib/libboost_math_c99f.a  
54.     /usr/local/lib/libboost_math_c99l.a  
55.     /usr/local/lib/libboost_math_tr1.a  
56.     /usr/local/lib/libboost_math_tr1f.a  
57.     /usr/local/lib/libboost_math_tr1l.a  
58.     /usr/local/lib/libboost_prg_exec_monitor.a  
59.     /usr/local/lib/libboost_program_options.a  
60.     /usr/local/lib/libboost_python.a  
61.     /usr/local/lib/libboost_random.a  
62.     /usr/local/lib/libboost_regex.a  
63.     /usr/local/lib/libboost_serialization.a  
64.     /usr/local/lib/libboost_signals.a  
65.     /usr/local/lib/libboost_system.a  
66.     /usr/local/lib/libboost_test_exec_monitor.a  
67.     /usr/local/lib/libboost_thread.a  
68.     /usr/local/lib/libboost_timer.a  
69.     /usr/local/lib/libboost_unit_test_framework.a  
70.     /usr/local/lib/libboost_wave.a  
71.     /usr/local/lib/libboost_wserialization.a  
72.   
73. Warning: You have unlinked kegs in your Cellar  
74. Leaving kegs unlinked can lead to build-trouble and cause brews that depend on  
75. those kegs to fail to run properly once built. Run `brew link` on these:  
76.   
77.     wget  
78. gerryyang@mba:bin$  

(6) 为什么选择Homebrew这个名字？
mxcl was too concerned with the beer theme and didn’t consider that the project may actually prove popular. By the time he realized it was too late. However, today, the first google hit for “homebrew” is not beer related ;-)

看来作者是个酒鬼！

(7) 关于更多地QA可以参考Homebrew的Wiki[4]

(8) 一些常用安装推荐

1. gerryyang@mba:bin$brew list  
2. coreutils  openssl  wget  xz  

Introduction to Coreutils 

The GNU Core Utilities are the basic file, shell and text manipulationutilities of the GNU operating system.
These are the core utilitieswhich are expected to exist on every operating system.