waitKey()函数，但它没有似乎工作正常。当按下任何键时，它总是返回255，按下任何键！我想知道它是否错误安装或者它是OpenCV本身的错误。任何想法来解决它将不胜感激。这是我程序的源代码：
#include "opencv2/highgui/highgui.hpp"
#include <iostream>
int main() {
int ch;
cv::namedWindow("Test waitKey()", cv::WINDOW_AUTOSIZE);
cv::Mat image = cv::Mat(100,100,CV_8U, cv::Scalar(0));
cv::imshow("Test waitKey()", image);
for (;;){
ch = cv::waitKey(1000);
std::cout << ch << std::endl; // always return 255
// and this if statement will never be executed!
if (ch == 'q') break;
}
return 0;
}
此处cv::getBuildInformation()函数的输出：
General configuration for OpenCV 3.2.0
=====================================
Version control: unknown
Platform:
Timestamp: 2017-01-14T14:50:25Z
Host: Darwin 16.3.0 x86_64
CMake: 3.7.2
CMake generator: Unix Makefiles
CMake build tool: /usr/bin/make
Configuration: RELEASE
C/C++:
Built as dynamic libs?: YES
C++ Compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++ (ver 8.0.0.8000042)
C++ flags (Release): -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -Wno-unnamed-type-template-args -Wno-comment -fdiagnostics-show-option -Wno-long-long -Qunused-arguments -Wno-semicolon-before-method-body -fno-omit-frame-pointer -msse -msse2 -mno-avx -msse3 -mno-ssse3 -mno-sse4.1 -mno-sse4.2 -fvisibility=hidden -fvisibility-inlines-hidden -O3 -DNDEBUG -DNDEBUG
C++ flags (Debug): -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -Wno-unnamed-type-template-args -Wno-comment -fdiagnostics-show-option -Wno-long-long -Qunused-arguments -Wno-semicolon-before-method-body -fno-omit-frame-pointer -msse -msse2 -mno-avx -msse3 -mno-ssse3 -mno-sse4.1 -mno-sse4.2 -fvisibility=hidden -fvisibility-inlines-hidden -g -O0 -DDEBUG -D_DEBUG
C Compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc
C flags (Release): -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -Wno-unnamed-type-template-args -Wno-comment -fdiagnostics-show-option -Wno-long-long -Qunused-arguments -Wno-semicolon-before-method-body -fno-omit-frame-pointer -msse -msse2 -mno-avx -msse3 -mno-ssse3 -mno-sse4.1 -mno-sse4.2 -fvisibility=hidden -fvisibility-inlines-hidden -O3 -DNDEBUG -DNDEBUG
C flags (Debug): -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -Wno-unnamed-type-template-args -Wno-comment -fdiagnostics-show-option -Wno-long-long -Qunused-arguments -Wno-semicolon-before-method-body -fno-omit-frame-pointer -msse -msse2 -mno-avx -msse3 -mno-ssse3 -mno-sse4.1 -mno-sse4.2 -fvisibility=hidden -fvisibility-inlines-hidden -g -O0 -DDEBUG -D_DEBUG
Linker flags (Release):
Linker flags (Debug):
ccache: NO
Precompiled headers: NO
Extra dependencies: -framework OpenCL -framework Cocoa -framework AVFoundation -framework CoreGraphics -framework CoreMedia -framework CoreVideo -framework QuartzCore -framework Accelerate
3rdparty dependencies: libjpeg libwebp libpng libtiff libjasper IlmImf zlib
OpenCV modules:
To be built: core flann imgproc ml photo video imgcodecs shape videoio highgui objdetect superres ts features2d calib3d stitching videostab python2
Disabled: world
Disabled by dependency: -
Unavailable: cudaarithm cudabgsegm cudacodec cudafeatures2d cudafilters cudaimgproc cudalegacy cudaobjdetect cudaoptflow cudastereo cudawarping cudev java python3 viz
GUI:
QT: NO
Cocoa: YES
OpenGL support: NO
VTK support: NO
Media I/O:
ZLib: build (ver 1.2.8)
JPEG: build (ver 90)
WEBP: build (ver 0.3.1)
PNG: build (ver 1.6.24)
TIFF: build (ver 42 - 4.0.2)
JPEG 2000: build (ver 1.900.1)
OpenEXR: build (ver 1.7.1)
GDAL: NO
GDCM: NO
Video I/O:
DC1394 1.x: NO
DC1394 2.x: NO
FFMPEG: NO
avcodec: NO
avformat: NO
avutil: NO
swscale: NO
avresample: NO
GStreamer: NO
OpenNI: NO
OpenNI PrimeSensor Modules: NO
OpenNI2: NO
PvAPI: NO
GigEVisionSDK: NO
Aravis SDK: NO
AVFoundation: YES
V4L/V4L2: NO/NO
XIMEA: NO
gPhoto2: NO
Parallel framework: GCD
Other third-party libraries:
Use IPP: 9.0.1 [9.0.1]
at: /Users/ngoclinhng/opencv/release/3rdparty/ippicv/ippicv_osx
Use IPP Async: NO
Use VA: NO
Use Intel VA-API/OpenCL: NO
Use Lapack: YES (-framework Accelerate)
Use Eigen: NO
Use Cuda: NO
Use OpenCL: YES
Use OpenVX: NO
Use custom HAL: NO
OpenCL: <Link with OpenCL library>
Link libraries: -framework OpenCL
Use AMDFFT: NO
Use AMDBLAS: NO
Python 2:
Interpreter: /usr/bin/python2.7 (ver 2.7.10)
Libraries: /usr/lib/libpython2.7.dylib (ver 2.7.10)
numpy: /System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/numpy/core/include (ver 1.8.0rc1)
packages path: lib/python2.7/site-packages
Python 3:
Interpreter: /Users/ngoclinhng/anaconda/bin/python3 (ver 3.5.2)
Python (for build): /usr/bin/python2.7
Java:
ant: NO
JNI: /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/System/Library/Frameworks/JavaVM.framework/Headers /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/System/Library/Frameworks/JavaVM.framework/Headers /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/System/Library/Frameworks/JavaVM.framework/Headers
Java wrappers: NO
Java tests: NO
Matlab: Matlab not found or implicitly disabled
Documentation:
Doxygen: NO
Tests and samples:
Tests: YES
Performance tests: YES
C/C++ Examples: NO
Install path: /usr/local
cvconfig.h is in: /Users/ngoclinhng/opencv/release
-----------------------------------------------------------------
答案 0 :(得分：2)
你通常必须用and结果用255来掩盖无关的位：
key = cv::waitKey(1000) & 255;
外部位可能是移位或控制键等。它们取决于操作系统。
检测到的按键还取决于您选择的窗口 - 您需要选择图像窗口（具有焦点）IIRC来检测按键 - 而不是从您启动程序的终端窗口。
答案 1 :(得分：2)
你应该使用cvWaitKey（n）代替〜 在OpenCV 3.1之后，当n毫秒内没有keydown时，cv :: waitKey（n）返回值从-1变为255。
答案 2 :(得分：-1)
在带有opencv 3.4的Mac上
class ArticlesController < ApplicationController
def show
@article = Article.find(params[:id])
end
def new
end
def create
@article = Article.new(article_params)
@article.save
redirect_to articles_path({:id => @article.id})
end
private
def article_params
params.require(:article).permit(:title, :text)
end
end