OpenCV 滑动条Trackbar C/C++/Python
OpenCV 滑动条Trackbar C/C++/Python
参考：
opencv 滑动条 cvCreateTrackbar()：http://blog.csdn.net/u012005313/article/details/46788445
createTrackbar：http://docs.opencv.org/2.4.11/modules/highgui/doc/user_interface.html#createtrackbar
Adding a Trackbar to our applications!：http://docs.opencv.org/2.4.11/doc/tutorials/highgui/trackbar/trackbar.html#adding-a-trackbar-to-our-applications
使用滑动条控制参数的改变，调用回调函数修改显示的图像，更直观的比对不同参数的变化
主要内容
C/C++/Python函数格式C++下调用滑动条C下调用滑动条Python下调用滑动条getTrackbarPos
C/C++/Python 函数格式
C/C++/Python 函数格式
C++ 函数：
int createTrackbar(const string& trackbarname, const string& winname,
int* value, int count, TrackbarCallback onChange=0, void* userdata=0)
参数：
trackbarname：滑动条名，滑动条的标识符，不同滑动条拥有不同的滑动条名winname：窗口名，滑动条想要绑定的窗口的名字value：可选，用于反映滑块位置。创建滑动条时可用此值指定滑块位置count：滑块最大值。最小值通常是0onChange：回调函数，函数原型为void Foo(int,void*).
- where the first parameter is the trackbar position and the second parameter is the user data (see the next parameter).
- If the callback is the NULL pointer, no callbacks are called, but only value is updated`
userdata：User data that is passed as is to the callback.
- It can be used to handle trackbar events without using global variables.
C 函数：
int cvCreateTrackbar(const char* trackbar_name, const char* window_name,
int* value, int count, CvTrackbarCallback on_change=NULL )
参数：
- trackbar_name：同上
- window_name：同上
- value：同上
- count：同上
- on_change：函数原型为
void Foo(int)
Python 函数：
def createTrackbar(trackbarName, windowName, value, count, onChange)
参数：同上，其中 onChange 回调函数有一个参数
C++ 下调用滑动条
C++ 下调用滑动条
程序 1：进行形态学膨胀操作，改变迭代次数
#include
#include
#include
using namespace std;
using namespace cv;
// 滑动条名
const string trackbarname = "expand";
// 窗口名
const string winname = "TrackbarDemo";
// 最大值
const int maxNum = 10;
// 预设值
int value = 3;
Mat img;
Mat res;
int dilation_type = MORPH_RECT;
int dilation_size = 1;
Mat element = getStructuringElement(dilation_type,
Size(2 * dilation_size + 1, 2 * dilation_size + 1),
Point(dilation_size, dilation_size));
void onExpand(int, void*) {
printf("value: %d\n", value);
dilate(img, res, element, Point(-1, -1),value);
imshow(winname, res);
}
int main(int argc, char* argv[]) {
img = imread("c:\\lena.jpg", -1);
if (img.empty()) {
exit(0);
}
res = img.clone();
namedWindow(winname);
createTrackbar(trackbarname, winname, &value, maxNum, onExpand, NULL);
onExpand(0, NULL);
waitKey(0);
return 0;
}
结果：
如果需要改变多个参数，可以使用多个滑动条
程序 2：改变迭代次数以及核大小
#include
#include
#include
using namespace std;
using namespace cv;
// 滑动条名
const string trackbarname1 = "interation";
const string trackbarname2 = "dilationSize";
// 窗口名
const string winname = "TrackbarDemo";
// 最大值
const int maxNum1 = 10;
const int maxNum2 = 5;
// 预设值
int interationValue = 3;
int dilationSize = 2;
Mat img;
Mat res;
int dilation_type = MORPH_RECT;
void onDilate(int, void*) {
printf("dilationSize: %d\n", dilationSize);
printf("interationValue: %d\n", interationValue);
Mat element = getStructuringElement(dilation_type,
Size(2 * dilationSize + 1, 2 * dilationSize + 1),
Point(dilationSize, dilationSize));
dilate(img, res, element, Point(-1, -1), interationValue);
imshow(winname, res);
}
int main(int argc, char* argv[]) {
img = imread("c:\\lena.jpg", -1);
if (img.empty()) {
exit(0);
}
res = img.clone();
namedWindow(winname);
createTrackbar(trackbarname1, winname, &interationValue, maxNum1, onDilate, NULL);
createTrackbar(trackbarname2, winname, &dilationSize, maxNum2, onDilate, NULL);
onDilate(0, NULL);
waitKey(0);
return 0;
}
结果：
C 下调用滑动条
C 下调用滑动条
程序 1：进行形态学膨胀操作，改变迭代次数
#include
#include
#include
#include
// 滑动条名
const char* trackbarname = "interation";
// 窗口名
const char* winanme = "TrackbarDemo";
// 最大值
const int maxNum = 10;
int interationValue = 3;
IplImage* img;
IplImage* res;
IplConvKernel* element;
void onDilate(int arg) {
printf("interationValue: %d\n", interationValue);
cvDilate(img, res, element, interationValue);
cvShowImage(winanme, res);
}
int main(int argc, char* argv[]) {
img = cvLoadImage("c:\\lena.jpg", CV_LOAD_IMAGE_UNCHANGED);
if (img->imageData == NULL) {
exit(0);
}
res = cvCreateImage(cvSize(img->width, img->height), img->depth, img->nChannels);
int dilationSize = 1;
int row = dilationSize * 2 + 1;
int col = dilationSize * 2 + 1;
element = cvCreateStructuringElementEx(2 * dilationSize + 1,
2 * dilationSize + 1, dilationSize, dilationSize, CV_SHAPE_RECT, NULL);
cvNamedWindow(winanme, CV_WINDOW_AUTOSIZE);
cvCreateTrackbar(trackbarname, winanme, &interationValue, maxNum, onDilate);
onDilate(0);
cvWaitKey(0);
cvReleaseStructuringElement(&element);
cvReleaseImage(&img);
cvReleaseImage(&res);
cvDestroyWindow(winanme);
return 0;
}
程序 2：改变迭代次数以及核大小
#include
#include
#include
#include
// 滑动条名
const char* trackbarname1 = "interation";
const char* trackbarname2 = "dilationSize";
// 窗口名
const char* winanme = "TrackbarDemo";
// 最大值
const int maxNum1 = 10;
const int maxNum2 = 5;
int interationValue = 3;
int dilationSize = 1;
IplImage* img;
IplImage* res;
IplConvKernel* element;
void onDilate(int arg) {
printf("interationValue: %d\n", interationValue);
printf("dilationSize: %d\n", dilationSize);
int row = dilationSize * 2 + 1;
int col = dilationSize * 2 + 1;
element = cvCreateStructuringElementEx(2 * dilationSize + 1,
2 * dilationSize + 1, dilationSize, dilationSize, CV_SHAPE_RECT, NULL);
cvDilate(img, res, element, interationValue);
cvShowImage(winanme, res);
cvReleaseStructuringElement(&element);
}
int main(int argc, char* argv[]) {
img = cvLoadImage("c:\\lena.jpg", CV_LOAD_IMAGE_UNCHANGED);
if (img->imageData == NULL) {
exit(0);
}
res = cvCreateImage(cvSize(img->width, img->height), img->depth, img->nChannels);
cvNamedWindow(winanme, CV_WINDOW_AUTOSIZE);
cvCreateTrackbar(trackbarname1, winanme, &interationValue, maxNum1, onDilate);
cvCreateTrackbar(trackbarname2, winanme, &dilationSize, maxNum2, onDilate);
onDilate(0);
cvWaitKey(0);
cvReleaseImage(&img);
cvReleaseImage(&res);
cvDestroyWindow(winanme);
return 0;
}
Python 下调用滑动条
Python 下调用滑动条
程序 1：进行形态学膨胀操作，改变迭代次数
# -*- coding: utf-8 -*-
import cv2
import os
trackbar_name = "interation"
win_name = "TrackbarDemo"
max_num = 10
value = 3
kernerl = cv2.getStructuringElement(cv2.MORPH_RECT, (3, 3))
def on_dialte(arg):
"""
膨胀操作
:param arg:
:return:
"""
value = cv2.getTrackbarPos(trackbar_name, win_name)
print "value:", value
res = cv2.dilate(img, kernerl, None, None, value)
cv2.imshow(win_name, res)
if __name__ == '__main__':
img = cv2.imread("c:\\lena.jpg", cv2.CV_LOAD_IMAGE_UNCHANGED)
if img is None:
os._exit(0)
cv2.namedWindow(win_name)
cv2.createTrackbar(trackbar_name, win_name, value, max_num, on_dialte)
on_dialte(0)
cv2.waitKey(0)
程序 2：改变迭代次数以及核大小
# -*- coding: utf-8 -*-
import cv2
import os
trackbar_name1 = "interation"
trackbar_name2 = "dilationSize"
win_name = "TrackbarDemo"
max_num1 = 10
max_num2 = 5
interation_value = 3
dilation_size = 1
def on_dilate(arg):
"""
形态学膨胀操作
:param arg:
:return:
"""
value = cv2.getTrackbarPos(trackbar_name1, win_name)
print "value:", value
size = cv2.getTrackbarPos(trackbar_name2, win_name)
print "size:", size
kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (2 * size + 1, 2 * size + 1))
res = cv2.dilate(img, kernel, None, None, value)
cv2.imshow(win_name, res)
if __name__ == '__main__':
img = cv2.imread("c:\\lena.jpg", cv2.CV_LOAD_IMAGE_UNCHANGED)
if img is None:
os._exit(0)
cv2.namedWindow(win_name)
cv2.createTrackbar(trackbar_name1, win_name, interation_value, max_num1, on_dilate)
cv2.createTrackbar(trackbar_name2, win_name, dilation_size, max_num2, on_dilate)
on_dilate(0)
cv2.waitKey(0)
getTrackbarPos
参考：getTrackbarPos
C++ 函数：
int getTrackbarPos(const string& trackbarname, const string& winname)
C 函数：
int cvGetTrackbarPos(const char* trackbar_name, const char* window_name)
Python 函数：
cv2.getTrackbarPos(trackbarname, winname) → retval
参数：
第一个：滑动条名
第二个：窗口名
返回值：指定窗口上指定滑动条的当前位置