在OpenCV中提高相机捕获分辨率
在我的C/C++程序中,我使用从我的网络摄像头中捕获图像。相机()可以以320x240、640x480和1280x960的分辨率进行拍摄。但是,出于某种奇怪的原因,OpenCV只提供分辨率为320x240的图像。使用cvSetCaptureProperty()和其他分辨率值更改分辨率的调用不起作用。如何使用我的网络摄像头以其他可能的分辨率拍摄图像?似乎没有解决方案。使用lifebelt77共享,可将分辨率提高到640x480。详情如下: 添加到highgui.h:在OpenCV中提高相机捕获分辨率,c,image,opencv,webcam,resolutions,C,Image,Opencv,Webcam,Resolutions,在我的C/C++程序中,我使用从我的网络摄像头中捕获图像。相机()可以以320x240、640x480和1280x960的分辨率进行拍摄。但是,出于某种奇怪的原因,OpenCV只提供分辨率为320x240的图像。使用cvSetCaptureProperty()和其他分辨率值更改分辨率的调用不起作用。如何使用我的网络摄像头以其他可能的分辨率拍摄图像?似乎没有解决方案。使用lifebelt77共享,可将分辨率提高到640x480。详情如下: 添加到highgui.h: #define CV_CAP_
#define CV_CAP_PROP_DIALOG_DISPLAY 8
#define CV_CAP_PROP_DIALOG_FORMAT 9
#define CV_CAP_PROP_DIALOG_SOURCE 10
#define CV_CAP_PROP_DIALOG_COMPRESSION 11
#define CV_CAP_PROP_FRAME_WIDTH_HEIGHT 12
static int icvSetPropertyCAM_VFW( CvCaptureCAM_VFW* capture, int property_id, double value )
{
int result = -1;
CAPSTATUS capstat;
CAPTUREPARMS capparam;
BITMAPINFO btmp;
switch( property_id )
{
case CV_CAP_PROP_DIALOG_DISPLAY:
result = capDlgVideoDisplay(capture->capWnd);
//SendMessage(capture->capWnd,WM_CAP_DLG_VIDEODISPLAY,0,0);
break;
case CV_CAP_PROP_DIALOG_FORMAT:
result = capDlgVideoFormat(capture->capWnd);
//SendMessage(capture->capWnd,WM_CAP_DLG_VIDEOFORMAT,0,0);
break;
case CV_CAP_PROP_DIALOG_SOURCE:
result = capDlgVideoSource(capture->capWnd);
//SendMessage(capture->capWnd,WM_CAP_DLG_VIDEOSOURCE,0,0);
break;
case CV_CAP_PROP_DIALOG_COMPRESSION:
result = capDlgVideoCompression(capture->capWnd);
break;
case CV_CAP_PROP_FRAME_WIDTH_HEIGHT:
capGetVideoFormat(capture->capWnd, &btmp, sizeof(BITMAPINFO));
btmp.bmiHeader.biWidth = floor(value/1000);
btmp.bmiHeader.biHeight = value-floor(value/1000)*1000;
btmp.bmiHeader.biSizeImage = btmp.bmiHeader.biHeight *
btmp.bmiHeader.biWidth * btmp.bmiHeader.biPlanes *
btmp.bmiHeader.biBitCount / 8;
capSetVideoFormat(capture->capWnd, &btmp, sizeof(BITMAPINFO));
break;
default:
break;
}
return result;
}
将函数icvSetPropertyCAM\u VFW添加到cvcap.cpp:
#define CV_CAP_PROP_DIALOG_DISPLAY 8
#define CV_CAP_PROP_DIALOG_FORMAT 9
#define CV_CAP_PROP_DIALOG_SOURCE 10
#define CV_CAP_PROP_DIALOG_COMPRESSION 11
#define CV_CAP_PROP_FRAME_WIDTH_HEIGHT 12
static int icvSetPropertyCAM_VFW( CvCaptureCAM_VFW* capture, int property_id, double value )
{
int result = -1;
CAPSTATUS capstat;
CAPTUREPARMS capparam;
BITMAPINFO btmp;
switch( property_id )
{
case CV_CAP_PROP_DIALOG_DISPLAY:
result = capDlgVideoDisplay(capture->capWnd);
//SendMessage(capture->capWnd,WM_CAP_DLG_VIDEODISPLAY,0,0);
break;
case CV_CAP_PROP_DIALOG_FORMAT:
result = capDlgVideoFormat(capture->capWnd);
//SendMessage(capture->capWnd,WM_CAP_DLG_VIDEOFORMAT,0,0);
break;
case CV_CAP_PROP_DIALOG_SOURCE:
result = capDlgVideoSource(capture->capWnd);
//SendMessage(capture->capWnd,WM_CAP_DLG_VIDEOSOURCE,0,0);
break;
case CV_CAP_PROP_DIALOG_COMPRESSION:
result = capDlgVideoCompression(capture->capWnd);
break;
case CV_CAP_PROP_FRAME_WIDTH_HEIGHT:
capGetVideoFormat(capture->capWnd, &btmp, sizeof(BITMAPINFO));
btmp.bmiHeader.biWidth = floor(value/1000);
btmp.bmiHeader.biHeight = value-floor(value/1000)*1000;
btmp.bmiHeader.biSizeImage = btmp.bmiHeader.biHeight *
btmp.bmiHeader.biWidth * btmp.bmiHeader.biPlanes *
btmp.bmiHeader.biBitCount / 8;
capSetVideoFormat(capture->capWnd, &btmp, sizeof(BITMAPINFO));
break;
default:
break;
}
return result;
}
并按如下所示编辑captureCAM\u VFW\u vtable:
static CvCaptureVTable captureCAM_VFW_vtable =
{
6,
(CvCaptureCloseFunc)icvCloseCAM_VFW,
(CvCaptureGrabFrameFunc)icvGrabFrameCAM_VFW,
(CvCaptureRetrieveFrameFunc)icvRetrieveFrameCAM_VFW,
(CvCaptureGetPropertyFunc)icvGetPropertyCAM_VFW,
(CvCaptureSetPropertyFunc)icvSetPropertyCAM_VFW, // was NULL
(CvCaptureGetDescriptionFunc)0
};
现在重建了highgui.dll我以前在linux中做过图像处理,跳过了OpenCV内置的摄像头功能,因为它(正如您所发现的)不完整 根据您的操作系统,通过普通通道直接访问硬件可能比通过openCV更幸运。如果您使用的是Linux,那么video4linux或video4linux2应该可以让您相对轻松地访问USB网络摄像头,并且您可以将libavc1394用于firewire。根据所使用的设备和示例代码的质量,您应该能够在一两个小时内使用所需的参数运行设备
编辑以添加:如果其窗口为空,则您可以自行添加。我想这并不难,但我从来没有这样做过。我强烈建议使用,它支持任何DirectShow设备(甚至同时支持多个设备),并且更易于配置。您将花五分钟的时间让它与OpenCV一起播放。我在Windows下使用OpenCV 1.1pre1(默认情况下,Windows下此版本的OpenCV使用视频输入库) 根据这些说明,我可以设置相机分辨率。注意,我调用了旧的cvCreateCameraCapture,而不是cvCaptureFromCam
capture = cvCreateCameraCapture(cameraIndex);
cvSetCaptureProperty( capture, CV_CAP_PROP_FRAME_WIDTH, 640 );
cvSetCaptureProperty( capture, CV_CAP_PROP_FRAME_HEIGHT, 480 );
videoFrame = cvQueryFrame(capture);
我用Logitech、Trust和飞利浦的网络摄像头进行了测试
cvQueryFrame(capture);
cvSetCaptureProperty( capture, CV_CAP_PROP_FRAME_WIDTH, any_supported_size );
cvSetCaptureProperty( capture, CV_CAP_PROP_FRAME_HEIGHT, any_supported_size);
cvQueryFrame(capture);
应该就够了 试试这个:
capture = cvCreateCameraCapture(-1);
//set resolution
cvSetCaptureProperty(capture, CV_CAP_PROP_FRAME_WIDTH, frameWidth);
cvSetCaptureProperty(capture, CV_CAP_PROP_FRAME_HEIGHT, frameHeight);
签出这张票:
“解决方案是使用较新的基于libv4l的包装器
但是如果您可以使用不同的Windows摄像头访问库,例如“videoInput”库,该库使用非常高效的DirectShow(DirectX的一部分)访问摄像头。或者,如果您有专业质量的摄像头,那么它通常会附带一个自定义API,允许您访问摄像头,您可以使用该API进行快速访问,并可以更改分辨率和许多其他功能。在Windows下尝试使用VideoInput library:
我正在使用debian和ubuntu,我遇到了同样的问题,我无法使用CV\u CAP\u PROP\u FRAME\u WIDTH和CV\u CAP\u PROP\u FRAME\u HEIGHT更改视频输入的分辨率 我发现原因是图书馆不见了。
我通过synaptic安装了lib4l dev,重建了OpenCV,问题解决了 我发布此消息是为了确保没有其他人在这个setproperty函数上浪费时间。我花了两天的时间在这件事上,以确保一切都不起作用。所以我找到了代码(我第一次安装了这个库)。这就是实际发生的情况-cvSetCaptureProperty,在CvCapture类中调用setProperty,而setProperty什么都不做。它只是返回false。 相反,我将使用另一个库为OpenCV提供一个捕获视频/图像的库。我正在使用OpenCV 2.2 cvSetCaptureProperty(捕获,CV_CAP_PROP_FRAME_WIDTH,WIDTH) cvSetCaptureProperty(捕捉、CV_CAP_PROP_FRAME_高度、高度) cvQueryFrame(捕获)
这在OpenCV 2.2中不起作用,但如果使用OpenCV 2.1,它将很好地工作 如果您在windows平台上,请尝试DirectShow(IAMStreamConfig)
当Aaron Haun指出我需要在使用set函数之前定义其参数时,我终于开始使用Python了
#Camera_Get_Set.py
#By Forrest L. Erickson of VRX Company Inc. 8-31-12.
#Opens the camera and reads and reports the settings.
#Then tries to set for higher resolution.
#Workes with Logitech C525 for resolutions 960 by 720 and 1600 by 896
import cv2.cv as cv
import numpy
CV_CAP_PROP_POS_MSEC = 0
CV_CAP_PROP_POS_FRAMES = 1
CV_CAP_PROP_POS_AVI_RATIO = 2
CV_CAP_PROP_FRAME_WIDTH = 3
CV_CAP_PROP_FRAME_HEIGHT = 4
CV_CAP_PROP_FPS = 5
CV_CAP_PROP_POS_FOURCC = 6
CV_CAP_PROP_POS_FRAME_COUNT = 7
CV_CAP_PROP_BRIGHTNESS = 8
CV_CAP_PROP_CONTRAST = 9
CV_CAP_PROP_SATURATION = 10
CV_CAP_PROP_HUE = 11
CV_CAPTURE_PROPERTIES = tuple({
CV_CAP_PROP_POS_MSEC,
CV_CAP_PROP_POS_FRAMES,
CV_CAP_PROP_POS_AVI_RATIO,
CV_CAP_PROP_FRAME_WIDTH,
CV_CAP_PROP_FRAME_HEIGHT,
CV_CAP_PROP_FPS,
CV_CAP_PROP_POS_FOURCC,
CV_CAP_PROP_POS_FRAME_COUNT,
CV_CAP_PROP_BRIGHTNESS,
CV_CAP_PROP_CONTRAST,
CV_CAP_PROP_SATURATION,
CV_CAP_PROP_HUE})
CV_CAPTURE_PROPERTIES_NAMES = [
"CV_CAP_PROP_POS_MSEC",
"CV_CAP_PROP_POS_FRAMES",
"CV_CAP_PROP_POS_AVI_RATIO",
"CV_CAP_PROP_FRAME_WIDTH",
"CV_CAP_PROP_FRAME_HEIGHT",
"CV_CAP_PROP_FPS",
"CV_CAP_PROP_POS_FOURCC",
"CV_CAP_PROP_POS_FRAME_COUNT",
"CV_CAP_PROP_BRIGHTNESS",
"CV_CAP_PROP_CONTRAST",
"CV_CAP_PROP_SATURATION",
"CV_CAP_PROP_HUE"]
capture = cv.CaptureFromCAM(0)
print ("\nCamera properties before query of frame.")
for i in range(len(CV_CAPTURE_PROPERTIES_NAMES)):
# camera_valeus =[CV_CAPTURE_PROPERTIES_NAMES, foo]
foo = cv.GetCaptureProperty(capture, CV_CAPTURE_PROPERTIES[i])
camera_values =[CV_CAPTURE_PROPERTIES_NAMES[i], foo]
# print str(camera_values)
print str(CV_CAPTURE_PROPERTIES_NAMES[i]) + ": " + str(foo)
print ("\nOpen a window for display of image")
cv.NamedWindow("Camera", 1)
while True:
img = cv.QueryFrame(capture)
cv.ShowImage("Camera", img)
if cv.WaitKey(10) == 27:
break
cv.DestroyWindow("Camera")
#cv.SetCaptureProperty(capture, CV_CAP_PROP_FRAME_WIDTH, 1024)
#cv.SetCaptureProperty(capture, CV_CAP_PROP_FRAME_HEIGHT, 768)
cv.SetCaptureProperty(capture, CV_CAP_PROP_FRAME_WIDTH, 1600)
cv.SetCaptureProperty(capture, CV_CAP_PROP_FRAME_HEIGHT, 896)
print ("\nCamera properties after query and display of frame.")
for i in range(len(CV_CAPTURE_PROPERTIES_NAMES)):
# camera_valeus =[CV_CAPTURE_PROPERTIES_NAMES, foo]
foo = cv.GetCaptureProperty(capture, CV_CAPTURE_PROPERTIES[i])
camera_values =[CV_CAPTURE_PROPERTIES_NAMES[i], foo]
# print str(camera_values)
print str(CV_CAPTURE_PROPERTIES_NAMES[i]) + ": " + str(foo)
print ("/nOpen a window for display of image")
cv.NamedWindow("Camera", 1)
while True:
img = cv.QueryFrame(capture)
cv.ShowImage("Camera", img)
if cv.WaitKey(10) == 27:
break
cv.DestroyWindow("Camera")
对于难以更改默认捕获分辨率(640 x 480)的用户来说,只有一个信息是有价值的!我用opencv 2.4.x和一个Logitech摄像头试验了一个这样的问题。。。找到了一个解决办法 我检测到的行为是,当相机捕获开始(cvCreateCameraCapture)时,默认格式设置为初始参数,所有更改高度或宽度的请求:
cvSetCaptureProperty( capture, CV_CAP_PROP_FRAME_WIDTH, ...
或
以后是不可能的!实际上,通过添加ioctl函数的返回错误,我发现V4l2驱动程序正在返回EBUSYfor thet请求!
因此,一种解决方法应该是直接在highgui/cap_v4l.cpp中更改默认值:
*#define DEFAULT_V4L_WIDTH 1280 // Originally 640*
*#define DEFAULT_V4L_HEIGHT 720 // Originally 480*
之后,我重新编译了opencv。。。到达后,获得1280 x 720,没有任何问题!当然,更好的解决方法应该是停止采集,更改参数,然后重新启动流,但我没有足够的fami