OpenCV(EmguCV)2.1新特性介紹之圖像差異StereoSGBM與設置窗口屬性SetWindowProperty(StereoSGBM Of OpenCV 2.1)
http://www.cnblogs.com/xrwang/archive/2010/04/29/StereoSGBMAndSetWindowProperty.html
作者：王先榮
上次介紹了OpenCV2.1中新增的圖像分割算法GrabCut，本文將介紹StereoSGBM與SetWindowProperty。其中StereoSGBM用於計算兩幅圖像間的差異圖，跟已有的StereoBM和StereoGC作用一樣，算法不同而已；SetWindowProperty用於設置窗口的屬性，目前僅可用於設置全屏屬性。
比較圖像間的差異StereoSGBM
StereoSGBM用於計算兩幅圖像間的差異圖，在OpenCV的在線文檔中有非常詳細的介紹，地址是：「http://opencv.willowgarage.com/documentation/cpp/camera_calibration_and_3d_reconstruction.html#stereosgbm」。參數非常多，如果不使用默認的參數，需要仔細查看每個參數的說明，以免出錯。OpenCV的具體實現在命名空間cv中的StereoSGBM類，目前還沒有對應的C風格封裝；EmguCV將其封裝在StereoSGBM類中。
StereoSGBM除了參數很多之外，使用起來蠻簡單的，如下所示：
// 創建StereoSGBM對象
StereoSGBM sgbm = new StereoSGBM(( int )nudMinDisparity.Value, ( int )nudNumDisparities.Value, ( int )nudSADWindowSize.Value, ( int )nudP1.Value,
( int )nudP2.Value, ( int )nudDisp12MaxDiff.Value, ( int )nudPreFilterCap.Value, ( int )nudUniquenessRatio.Value,
( int )nudSpeckleWindowSize.Value, ( int )nudSpeckleRange.Value, chkFullDP.Checked);
// 查找兩幅圖像間的相關性（差異）
sgbm.FindStereoCorrespondence(leftImage, rightImage, disparityImage);
// 顯示結果
pbDisparity.Image = disparityImage.Bitmap;
// 釋放資源
sgbm.Dispose();
完整的示例（附帶了StereoBM和StereoGC的示例）請看：
StereoSGBM完整示例
using
System;
using
System.Collections.Generic;
using
System.ComponentModel;
using
System.Data;
using
System.Drawing;
using
System.Linq;
using
System.Text;
using
System.Windows.Forms;
using
System.Diagnostics;
using
System.Runtime.InteropServices;
using
Emgu.CV;
using
Emgu.CV.CvEnum;
using
Emgu.CV.Structure;
namespace
NewFeaturesOfOpenCV2._1
{
public
partial
class
FormStereoCorrespondence : Form
{
//
私有成員
private
string
leftImageFileName
=
"
wky_sls_2272x1704.jpg
"
;
//
左邊的圖像文件名
private
string
rightImageFileName
=
"
wky_sls_2272x1704_2.jpg
"
;
//
右邊的圖像文件名
private
Image
<
Gray, Byte
>
leftImage
=
null
;
//
左邊的灰度圖像
private
Image
<
Gray, Byte
>
rightImage
=
null
;
//
右邊的灰度圖像
private
Image
<
Gray, Int16
>
disparityImage
=
null
;
//
差異圖像
private
Stopwatch sw
=
new
Stopwatch();
//
計時器
public
FormStereoCorrespondence()
{
InitializeComponent();
}
//
設置SGBM的默認參數
private
void
btnFillDefaultParameters_Click(
object
sender, EventArgs e)
{
nudSADWindowSize.Value
=
3
;
nudP1.Value
=
0
;
nudP2.Value
=
0
;
nudDisp12MaxDiff.Value
=
0
;
nudPreFilterCap.Value
=
0
;
nudUniquenessRatio.Value
=
0
;
nudSpeckleWindowSize.Value
=
0
;
nudSpeckleRange.Value
=
0
;
chkFullDP.Checked
=
false
;
}
//
設置SGBM的推薦參數
private
void
btnFillRecommendedParameters_Click(
object
sender, EventArgs e)
{
nudUniquenessRatio.Value
=
5
;
nudSpeckleWindowSize.Value
=
50
;
nudSpeckleRange.Value
=
16
;
}
//
窗體加載時
private
void
FormStereoCorrespondence_Load(
object
sender, EventArgs e)
{
//
設置提示
toolTip.SetToolTip(nudNumDisparities,
"
必須大於0，且能被16除盡
"
);
toolTip.SetToolTip(nudSADWindowSize,
"
缺省為0；如果指定則必須是正奇數，推薦值為3～11
"
);
toolTip.SetToolTip(nudP1,
"
缺省為0；推薦值為8*number_of_image_channels*SADWindowSize*SADWindowSize
"
);
toolTip.SetToolTip(nudP2,
"
缺省為0；如果指定則P2>P1，推薦值為32*number_of_image_channels*SADWindowSize*SADWindowSize
"
);
toolTip.SetToolTip(nudDisp12MaxDiff,
"
如果設置為負值，則跳過左右差異檢查
"
);
toolTip.SetToolTip(nudUniquenessRatio,
"
缺省為0，推薦值為5～15
"
);
toolTip.SetToolTip(nudSpeckleWindowSize,
"
缺省為0，推薦值為50～200
"
);
toolTip.SetToolTip(nudSpeckleRange,
"
缺省為0；如果指定則必須是能被16整除的正數，推薦值為16或者32
"
);
//
初始化圖像
InitImage(
true
);
InitImage(
false
);
}
//
加載圖像1
private
void
btnLoadLeftImage_Click(
object
sender, EventArgs e)
{
LoadImage(
true
);
}
//
加載圖像2
private
void
btnLoadRightImage_Click(
object
sender, EventArgs e)
{
LoadImage(
false
);
}
///
<summary>
///
加載圖像
///
</summary>
///
<param name="isLeft">
是左邊的圖像嗎？
</param>
private
void
LoadImage(
bool
isLeft)
{
OpenFileDialog ofd
=
new
OpenFileDialog();
ofd.CheckFileExists
=
true
;
ofd.DefaultExt
=
"
jpg
"
;
ofd.Filter
=
"
圖片文件|*.jpg;*.png;*.bmp|所有文件|*.*
"
;
if
(ofd.ShowDialog(
this
)
==
DialogResult.OK)
{
if
(ofd.FileName
!=
""
)
{
if
(isLeft)
leftImageFileName
=
ofd.FileName;
else
rightImageFileName
=
ofd.FileName;
InitImage(isLeft);
}
}
ofd.Dispose();
}
///
<summary>
///
初始化圖像
///
</summary>
///
<param name="isLeft">
是左邊的圖像嗎？
</param>
private
void
InitImage(
bool
isLeft)
{
if
(isLeft)
{
Image
<
Bgr, Byte
>
image
=
new
Image
<
Bgr,
byte
>
(leftImageFileName);
pbLeft.Image
=
image.Bitmap;
if
(leftImage
!=
null
)
leftImage.Dispose();
leftImage
=
image.Convert
<
Gray, Byte
>
();
if
(disparityImage
!=
null
)
disparityImage.Dispose();
disparityImage
=
new
Image
<
Gray,
short
>
(leftImage.Size);
image.Dispose();
}
else
{
Image
<
Bgr, Byte
>
image
=
new
Image
<
Bgr,
byte
>
(rightImageFileName);
pbRight.Image
=
image.Bitmap;
if
(rightImage
!=
null
)
rightImage.Dispose();
rightImage
=
image.Convert
<
Gray, Byte
>
();
image.Dispose();
}
}
//
開始計算
private
void
btnCalc_Click(
object
sender, EventArgs e)
{
if
(leftImage.Size
!=
rightImage.Size)
{
MessageBox.Show(
this
,
"
兩幅圖像的尺寸不一致，不能比較。
"
,
"
錯誤提示
"
);
return
;
}
if
(tcStereo.SelectedTab
==
tpStereoSGBM)
{
StereoSGBM sgbm
=
new
StereoSGBM((
int
)nudMinDisparity.Value, (
int
)nudNumDisparities.Value, (
int
)nudSADWindowSize.Value, (
int
)nudP1.Value,
(
int
)nudP2.Value, (
int
)nudDisp12MaxDiff.Value, (
int
)nudPreFilterCap.Value, (
int
)nudUniquenessRatio.Value,
(
int
)nudSpeckleWindowSize.Value, (
int
)nudSpeckleRange.Value, chkFullDP.Checked);
sw.Stop();
sw.Start();
sgbm.FindStereoCorrespondence(leftImage, rightImage, disparityImage);
sw.Stop();
pbDisparity.Image
=
disparityImage.Bitmap;
sgbm.Dispose();
lblStatus.Text
=
string
.Format(
"
SGBM比較耗時{0:F04}毫秒。
"
, sw.ElapsedMilliseconds);
}
else
if
(tcStereo.SelectedTab
==
tpStereoBM)
{
STEREO_BM_TYPE type
=
cbBMType.Text
==
"
BASIC
"
?
STEREO_BM_TYPE.BASIC : (cbBMType.Text
==
"
FISH_EYE
"
?
STEREO_BM_TYPE.FISH_EYE : STEREO_BM_TYPE.NARROW);
StereoBM bm
=
new
StereoBM(type, (
int
)nudBMNumberOfDisparities.Value);
sw.Stop();
sw.Start();
bm.FindStereoCorrespondence(leftImage, rightImage, disparityImage);
sw.Stop();
pbDisparity.Image
=
disparityImage.Bitmap;
bm.Dispose();
lblStatus.Text
=
string
.Format(
"
BM比較耗時{0:F04}毫秒。
"
, sw.ElapsedMilliseconds);
}
else
if
(tcStereo.SelectedTab
==
tpStereoGC)
{
StereoGC gc
=
new
StereoGC((
int
)nudGCNumberOfDisparities.Value, (
int
)nudGCMaxIters.Value);
Image
<
Gray, Int16
>
rightDisparityImage
=
new
Image
<
Gray,
short
>
(leftImage.Size);
sw.Stop();
sw.Start();
gc.FindStereoCorrespondence(leftImage, rightImage, disparityImage, rightDisparityImage);
sw.Stop();
CvInvoke.cvConvertScale(rightDisparityImage.Ptr, rightDisparityImage.Ptr, 16d, 0d);
CvInvoke.cvConvertScale(disparityImage.Ptr, disparityImage.Ptr,
-
16d, 0d);
pbDisparity.Image
=
rightDisparityImage.Bitmap;
rightDisparityImage.Dispose();
gc.Dispose();
lblStatus.Text
=
string
.Format(
"
GC比較耗時{0:F04}毫秒。
"
, sw.ElapsedMilliseconds);
}
}
//
關閉窗口時
private
void
FormStereoCorrespondence_FormClosed(
object
sender, FormClosedEventArgs e)
{
//
釋放資源
if
(leftImage
!=
null
)
leftImage.Dispose();
if
(rightImage
!=
null
)
rightImage.Dispose();
if
(disparityImage
!=
null
)
disparityImage.Dispose();
}
}
}
設置窗口屬性SetWindowProperty
目前只能用SetWindowProperty來設置窗口的全屏屬性——全屏或者普通窗口。其實OpenCV2.1中還增加了一個名為cvGetWindowProperty的函數，用於獲取窗口的屬性，更新說明中沒有提到而已。由於目前還沒有這個函數的相關文檔，我就詳細點說說。
1.函數原型、參數說明及提示
void cvSetWindowProperty(const char* name, int prop_id, double prop_value)
作用：設置窗口的屬性
返回值：無
參數：
name——窗口名稱，對應於用cvNamedWindow創建窗口時使用的名稱；
prop_id——屬性id，目前有兩種屬性：CV_WND_PROP_FULLSCREEN （=0）和CV_WND_PROP_AUTOSIZE（=1），但是僅CV_WND_PROP_FULLSCREEN有用；
prop_value——屬性值，如果設置全屏屬性，則該值可能有：CV_WINDOW_NORMAL（=0）和CV_WINDOW_FULLSCREEN （=1）。
備注：（1）cvSetWindowProperty目前只能用於設置窗口的全屏屬性；（2）在設置該屬性前，要求窗口不能是AUTOSIZE的，否則設置無效；（3）基於第2點原因，在創建窗口時不能省略flag參數（即不能使用其默認值CV_WINDOW_AUTOSIZE）；（4）由於EmguCV封裝的CvInvoke.cvNamedWindow強制使用了AUTOSIZE參數，因此不能使用它來創建窗口，需要自行進行P/Invoke調用；（5）OpenCV2.1更新文檔中的使用示例是錯誤的，不要模仿。
double cvGetWindowProperty(const char* name, int prop_id)
作用：獲取窗口的屬性
返回值：返回窗口的屬性值
參數：同cvSetWindowProperty
2.示例
您可以按如下所示使用cvSetWindowProperty：
cvSetWindowProperty(windowName, CV_WND_PROP_FULLSCREEN, CV_WINDOW_FULLSCREEN);
完整的示例請看：
完整的cvSetWindowProperty示例
//
全屏窗口
private
void
btnSetWindowProperty_Click(
object
sender, EventArgs e)
{
Image
<
Bgr, Byte
>
image
=
new
Image
<
Bgr,
byte
>
(
"
wky_qiao_2272x1704.jpg
"
);
string
windowName
=
"
stereoGC left disparity
"
;
cvNamedWindow(windowName,
0
);
cvResizeWindow(windowName,
640
,
480
);
cvMoveWindow(windowName,
100
,
100
);
cvSetWindowProperty(windowName, CV_WND_PROP_FULLSCREEN, CV_WINDOW_FULLSCREEN);
CvInvoke.cvShowImage(windowName, image.Ptr);
CvInvoke.cvWaitKey(
0
);
CvInvoke.cvDestroyWindow(windowName);
image.Dispose();
}
//
定義跟窗口相關的常量
public
const
int
CV_WND_PROP_FULLSCREEN
=
0
;
public
const
int
CV_WND_PROP_AUTOSIZE
=
1
;
public
const
double
CV_WINDOW_NORMAL
=
0
;
public
const
double
CV_WINDOW_FULLSCREEN
=
1
;
public
const
int
CV_WINDOW_AUTOSIZE
=
1
;
//
跟窗口有關的P/Invoke調用
//
設置窗口屬性，目前只能設置CV_WND_PROP_FULLSCREEN
[System.Runtime.InteropServices.DllImportAttribute(
"
highgui210.dll
"
, EntryPoint
=
"
cvSetWindowProperty
"
)]
public
static
extern
void
cvSetWindowProperty([System.Runtime.InteropServices.InAttribute()] [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.LPStr)]
string
name,
int
prop_id,
double
prop_value);
//
調整窗口的尺寸
[System.Runtime.InteropServices.DllImportAttribute(
"
highgui210.dll
"
, EntryPoint
=
"
cvResizeWindow
"
)]
public
static
extern
void
cvResizeWindow([System.Runtime.InteropServices.InAttribute()] [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.LPStr)]
string
name,
int
width,
int
height);
//
移動窗口
[System.Runtime.InteropServices.DllImportAttribute(
"
highgui210.dll
"
, EntryPoint
=
"
cvMoveWindow
"
)]
public
static
extern
void
cvMoveWindow([System.Runtime.InteropServices.InAttribute()] [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.LPStr)]
string
name,
int
x,
int
y);
//
創建指定名稱的窗口
[System.Runtime.InteropServices.DllImportAttribute(
"
highgui210.dll
"
, EntryPoint
=
"
cvNamedWindow
"
)]
public
static
extern
int
cvNamedWindow([System.Runtime.InteropServices.InAttribute()] [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.LPStr)]
string
name,
int
flags);
//
獲取窗口對應的句柄HWnd
[System.Runtime.InteropServices.DllImportAttribute(
"
highgui210.dll
"
, EntryPoint
=
"
cvGetWindowHandle
"
)]
public
static
extern
System.IntPtr cvGetWindowHandle([System.Runtime.InteropServices.InAttribute()] [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.LPStr)]
string
name);
//
獲取指定句柄對應的窗口名稱
[System.Runtime.InteropServices.DllImportAttribute(
"
highgui210.dll
"
, EntryPoint
=
"
cvGetWindowName
"
)]
public
static
extern
System.IntPtr cvGetWindowName(System.IntPtr windowHandle);
//
獲取窗口的屬性
[System.Runtime.InteropServices.DllImportAttribute(
"
highgui210.dll
"
, EntryPoint
=
"
cvGetWindowProperty
"
)]
public
static
extern
double
cvGetWindowProperty([System.Runtime.InteropServices.InAttribute()] [System.Runtime.InteropServices.MarshalAsAttribute(System.Runtime.InteropServices.UnmanagedType.LPStr)]
string
name,
int
prop_id);
}
感謝您耐心看完本文，希望對您有所幫助。
歡迎轉載，但是請注明出處，保留作者。