Hi all,
I’m beginner at OpenGL,
I want to display the video from a camera capture in the OpenGL window, then draw some contours or fonts in this window, and these contours or fonts will move or rotate all the time.
I have 2 problems about this:
(1) I’ve tried to use the OpenCV to get the camera capture, Iplimage it and texture it in the OpenGL window, it works but still have a problem of the Iplimage should be 2^X (like 256, 515) dimension, then it calls some distortion.
(2) When add some objects (eg. a plane) in the above (1) OpenGL window, I found when I try to rotate the plane, the camera video texture also rotate together with it, but I just want the object(the plane) rotate, the camera video act as the background.
I use Ubuntu 9.10, Eclipse, Opencv, Glut to do this.
Please help, here are the codes, thanks!!!
#include “cv.h”
#include “cxcore.h”
#include “highgui.h”
#include “ml.h”
#include “cvaux.h”
#include <iostream>
#include <stdlib.h>
#include<stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include<time.h>
#include<stdlib.h>
#include <GL/gl.h>
#include <GL/glut.h>
IplImage *ipl_src_camera = NULL;
IplImage *ipl_src_camera_resize = NULL;
IplImage frame = NULL;
CvCapture capture = NULL;
int nFrmNum = 0;
GLuint texture_list_camera;
void texture_load_from_camera() {
/*
- when using the camera direct rendering,
- should shut down the DEPTH_TEST function;
*/
glDisable(GL_DEPTH_TEST);
ipl_src_camera_resize = cvCreateImage(cvSize(256, 256), IPL_DEPTH_8U, 3);
capture = cvCaptureFromCAM(0);
cvNamedWindow(“CV window”);
while (frame = cvQueryFrame(capture)) {
nFrmNum++;
if (nFrmNum == 1) {
ipl_src_camera = cvCreateImage(cvSize(frame->width, frame->height),IPL_DEPTH_8U, 3);
} else {
cvCopy(frame, ipl_src_camera, 0);
cvResize(ipl_src_camera, ipl_src_camera_resize);
cvFlip(ipl_src_camera_resize, NULL, 0);
cvShowImage(“CV window”, ipl_src_camera_resize);
printf("load texture from camera
");
glPushMatrix();
glBindTexture(GL_TEXTURE_2D, texture_list_camera);
glPixelStorei(GL_UNPACK_ALIGNMENT, texture_list_camera);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
glShadeModel(GL_SMOOTH);
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
glEnable(GL_TEXTURE_2D);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8,
ipl_src_camera_resize->width,
ipl_src_camera_resize->height, 0, GL_BGR_EXT,
GL_UNSIGNED_BYTE, ipl_src_camera_resize->imageData);
//draw the plan to display the camera video;
glBegin(GL_QUADS);
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-1.0f, -1.0f, 0.0f);
glTexCoord2f(1.0f, 0.0f);
glVertex3f(1.0f, -1.0f, 0.0f);
glTexCoord2f(1.0f, 1.0f);
glVertex3f(1.0f, 1.0f, 0.0f);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-1.0f, 1.0f, 0.0f);
glEnd();
// draw another smaller plane on the camera video background
glRotatef(-_angle, 1.0f, 1.0f, 0.0f);
glBegin(GL_QUADS);
glVertex3f(-0.5f, -1.0f, 0.0f);
glVertex3f(1.0f, -0.5f, 0.0f);
glVertex3f(1.0f, 1.0f, 0.0f);
glVertex3f(-0.3f, 0.2f, 0.0f);
glEnd();
}
if (cvWaitKey(2) >= 0) {
cvReleaseImage(&ipl_src_camera);
cvReleaseImage(&ipl_src_camera_resize);
cvDestroyWindow(“CV window”);
break;
}
}
void handle_resizeWindow(int w, int h) {
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0, (float) w / (float) h, 1.0, 200.0);
}
void handle_keyPress(unsigned char key, int x, int y) {
switch (key) {
case 27: //Escape key
exit(0);
}
}
//Called every 25 milliseconds
void handle_update(int value) {
_angle += 0.2f;
if (_angle > 360) {
_angle -= 360;
}
glutPostRedisplay();
glutTimerFunc(25, handle_update, 0);
}
void handle_display() {
static int time_base = 0, frame = 0;
frame++;
// Get the number of milliseconds since “glutInit” has been called.
int time = glutGet(GLUT_ELAPSED_TIME);
if (time - time_base > 1000) {
sprintf(&title[44], " (%3.2f FPS)", frame * 1000.0f
/ (time - time_base));
glutSetWindowTitle(title);
time_base = time;
frame = 0;
}
}
void glInit(int argc, char** argv) {
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(400, 400);
glutCreateWindow(title);
glEnable(GL_DEPTH_TEST);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_NORMALIZE);
glEnable(GL_COLOR_MATERIAL);
}
int main(int argc, char** argv) {
glInit(argc, argv);
glutKeyboardFunc(handle_keyPress);
glutReshapeFunc(handle_resizeWindow);
glutTimerFunc(25, handle_update, 0);
glutDisplayFunc(handle_display);
texture_load_from_camera();
glutMainLoop();
return 0;
}