GraphUtils.cpp

//------------------------------------------------------------------------------
// Graphing functions for OpenCV.	Part of "ImageUtils.cpp", a set of handy utility functions for dealing with images in OpenCV.
// by Shervin Emami (http://www.shervinemami.co.cc/) on 20th May, 2010.
//------------------------------------------------------------------------------

#define USE_HIGHGUI		// Enable this to display graph windows using OpenCV's HighGUI. (Supports Windows, Linux & Mac, but not iPhone).

#include <stdio.h>
#include <iostream>
//#include <tchar.h>

// OpenCV
#include <cv.h>
#include <cxcore.h>
#ifdef USE_HIGHGUI
	#include <highgui.h>
#endif

#ifndef UCHAR
	typedef unsigned char UCHAR;
#endif

#include "GraphUtils.h"



//------------------------------------------------------------------------------
// Graphing functions
//------------------------------------------------------------------------------
const CvScalar BLACK = CV_RGB(0,0,0);
const CvScalar WHITE = CV_RGB(255,255,255);
const CvScalar GREY = CV_RGB(150,150,150);

int countGraph = 0;	// Used by 'getGraphColor()'
CvScalar customGraphColor;
int usingCustomGraphColor = 0;

// Get a new color to draw graphs. Will use the latest custom color, or change between blue, green, red, dark-blue, dark-green and dark-red until a new image is created.
CvScalar getGraphColor(void)
{
	if (usingCustomGraphColor) {
		usingCustomGraphColor = 0;
		return customGraphColor;
	}

	countGraph++;
	switch (countGraph) {
	case 1:	return CV_RGB(60,60,255);	// light-blue
	case 2:	return CV_RGB(60,255,60);	// light-green
	case 3:	return CV_RGB(255,60,40);	// light-red
	case 4:	return CV_RGB(0,210,210);	// blue-green
	case 5:	return CV_RGB(180,210,0);	// red-green
	case 6:	return CV_RGB(210,0,180);	// red-blue
	case 7:	return CV_RGB(0,0,185);		// dark-blue
	case 8:	return CV_RGB(0,185,0);		// dark-green
	case 9:	return CV_RGB(185,0,0);		// dark-red
	default:
		countGraph = 0;	// start rotating through colors again.
		return CV_RGB(200,200,200);	// grey
	}
}
// Call 'setGraphColor()' to reset the colors that will be used for graphs.
void setGraphColor(int index)
{
	countGraph = index;
	usingCustomGraphColor = 0;	// dont use a custom color.
}
// Specify the exact color that the next graph should be drawn as.
void setCustomGraphColor(int R, int B, int G)
{
	customGraphColor = CV_RGB(R, G, B);
	usingCustomGraphColor = 1;	// show that it will be used.
}

// Draw the graph of an array of floats into imageDst or a new image, between minV & maxV if given.
// Remember to free the newly created image if imageDst is not given.
IplImage* drawFloatGraph(const float *arraySrc, int nArrayLength, IplImage *imageDst, float minV, float maxV, int width, int height, char *graphLabel, bool showScale)
{
	int w = width;
	int h = height;
	int b = 10;		// border around graph within the image
	if (w <= 20)
		w = nArrayLength + b*2;	// width of the image
	if (h <= 20)
		h = 220;

	int s = h - b*2;// size of graph height
	float xscale = 1.0;
	if (nArrayLength > 1)
		xscale = (w - b*2) / (float)(nArrayLength-1);	// horizontal scale
	IplImage *imageGraph;	// output image

	// Get the desired image to draw into.
	if (!imageDst) {
		// Create an RGB image for graphing the data
		imageGraph = cvCreateImage(cvSize(w,h), 8, 3);

		// Clear the image
		cvSet(imageGraph, WHITE);
	}
	else {
		// Draw onto the given image.
		imageGraph = imageDst;
	}
	if (!imageGraph) {
		std::cerr << "ERROR in drawFloatGraph(): Couldn't create image of " << w << " x " << h << std::endl;
		exit(1);
	}
	CvScalar colorGraph = getGraphColor();	// use a different color each time.

	// If the user didnt supply min & mav values, find them from the data, so we can draw it at full scale.
	if (fabs(minV) < 0.0000001f && fabs(maxV) < 0.0000001f) {
		for (int i=0; i<nArrayLength; i++) {
			float v = (float)arraySrc[i];
			if (v < minV)
				minV = v;
			if (v > maxV)
				maxV = v;
		}
	}
	float diffV = maxV - minV;
	if (diffV == 0)
		diffV = 0.00000001f;	// Stop a divide-by-zero error
	float fscale = (float)s / diffV;

	// Draw the horizontal & vertical axis
	int y0 = cvRound(minV*fscale);
	cvLine(imageGraph, cvPoint(b,h-(b-y0)), cvPoint(w-b, h-(b-y0)), BLACK);
	cvLine(imageGraph, cvPoint(b,h-(b)), cvPoint(b, h-(b+s)), BLACK);

	// Write the scale of the y axis
	CvFont font;
	cvInitFont(&font,CV_FONT_HERSHEY_PLAIN,0.55,0.7, 0,1,CV_AA);	// For OpenCV 1.1
	if (showScale) {
		//cvInitFont(&font,CV_FONT_HERSHEY_PLAIN,0.5,0.6, 0,1, CV_AA);	// For OpenCV 2.0
		CvScalar clr = GREY;
		char text[16];
		sprintf_s(text, sizeof(text)-1, "%.1f", maxV);
		cvPutText(imageGraph, text, cvPoint(1, b+4), &font, clr);
		// Write the scale of the x axis
		sprintf_s(text, sizeof(text)-1, "%d", (nArrayLength-1) );
		cvPutText(imageGraph, text, cvPoint(w-b+4-5*strlen(text), (h/2)+10), &font, clr);
	}

	// Draw the values
	CvPoint ptPrev = cvPoint(b,h-(b-y0));	// Start the lines at the 1st point.
	for (int i=0; i<nArrayLength; i++) {
		int y = cvRound((arraySrc[i] - minV) * fscale);	// Get the values at a bigger scale
		int x = cvRound(i * xscale);
		CvPoint ptNew = cvPoint(b+x, h-(b+y));
		cvLine(imageGraph, ptPrev, ptNew, colorGraph, 1, CV_AA);	// Draw a line from the previous point to the new point
		ptPrev = ptNew;
	}

	// Write the graph label, if desired
	if (graphLabel != NULL && strlen(graphLabel) > 0) {
		//cvInitFont(&font,CV_FONT_HERSHEY_PLAIN, 0.5,0.7, 0,1,CV_AA);
		cvPutText(imageGraph, graphLabel, cvPoint(30, 10), &font, CV_RGB(0,0,0));	// black text
	}

	return imageGraph;
}

// Draw the graph of an array of ints into imageDst or a new image, between minV & maxV if given.
// Remember to free the newly created image if imageDst is not given.
IplImage* drawIntGraph(const int *arraySrc, int nArrayLength, IplImage *imageDst, int minV, int maxV, int width, int height, char *graphLabel, bool showScale)
{
	int w = width;
	int h = height;
	int b = 10;		// border around graph within the image
	if (w <= 20)
		w = nArrayLength + b*2;	// width of the image
	if (h <= 20)
		h = 220;

	int s = h - b*2;// size of graph height
	float xscale = 1.0;
	if (nArrayLength > 1)
		xscale = (w - b*2) / (float)(nArrayLength-1);	// horizontal scale
	IplImage *imageGraph;	// output image

	// Get the desired image to draw into.
	if (!imageDst) {
		// Create an RGB image for graphing the data
		imageGraph = cvCreateImage(cvSize(w,h), 8, 3);

		// Clear the image
		cvSet(imageGraph, WHITE);
	}
	else {
		// Draw onto the given image.
		imageGraph = imageDst;
	}
	if (!imageGraph) {
		std::cerr << "ERROR in drawIntGraph(): Couldn't create image of " << w << " x " << h << std::endl;
		exit(1);
	}
	CvScalar colorGraph = getGraphColor();	// use a different color each time.

	// If the user didnt supply min & mav values, find them from the data, so we can draw it at full scale.
	if (minV == 0 && maxV == 0) {
		for (int i=0; i<nArrayLength; i++) {
			int v = arraySrc[i];
			if (v < minV)
				minV = v;
			if (v > maxV)
				maxV = v;
		}
	}
	int diffV = maxV - minV;
	if (diffV == 0)
		diffV = 1;	// Stop a divide-by-zero error
	float fscale = (float)s / (float)diffV;

	// Draw the horizontal & vertical axis
	int y0 = cvRound(minV*fscale);
	cvLine(imageGraph, cvPoint(b,h-(b-y0)), cvPoint(w-b, h-(b-y0)), BLACK);
	cvLine(imageGraph, cvPoint(b,h-(b)), cvPoint(b, h-(b+s)), BLACK);

	// Write the scale of the y axis
	CvFont font;
	cvInitFont(&font,CV_FONT_HERSHEY_PLAIN,0.55,0.7, 0,1,CV_AA);	// For OpenCV 1.1
	if (showScale) {
		//cvInitFont(&font,CV_FONT_HERSHEY_PLAIN,0.5,0.6, 0,1, CV_AA);	// For OpenCV 2.0
		CvScalar clr = GREY;
		char text[16];
		sprintf_s(text, sizeof(text)-1, "%.1f", maxV);
		cvPutText(imageGraph, text, cvPoint(1, b+4), &font, clr);
		// Write the scale of the x axis
		sprintf_s(text, sizeof(text)-1, "%d", (nArrayLength-1) );
		cvPutText(imageGraph, text, cvPoint(w-b+4-5*strlen(text), (h/2)+10), &font, clr);
	}

	// Draw the values
	CvPoint ptPrev = cvPoint(b,h-(b-y0));	// Start the lines at the 1st point.
	for (int i=0; i<nArrayLength; i++) {
		int y = cvRound((arraySrc[i] - minV) * fscale);	// Get the values at a bigger scale
		int x = cvRound(i * xscale);
		CvPoint ptNew = cvPoint(b+x, h-(b+y));
		cvLine(imageGraph, ptPrev, ptNew, colorGraph, 1, CV_AA);	// Draw a line from the previous point to the new point
		ptPrev = ptNew;
	}

	// Write the graph label, if desired
	if (graphLabel != NULL && strlen(graphLabel) > 0) {
		//cvInitFont(&font,CV_FONT_HERSHEY_PLAIN, 0.5,0.7, 0,1,CV_AA);
		cvPutText(imageGraph, graphLabel, cvPoint(30, 10), &font, CV_RGB(0,0,0));	// black text
	}

	return imageGraph;
}

// Draw the graph of an array of uchars into imageDst or a new image, between minV & maxV if given..
// Remember to free the newly created image if imageDst is not given.
IplImage* drawUCharGraph(const uchar *arraySrc, int nArrayLength, IplImage *imageDst, int minV, int maxV, int width, int height, char *graphLabel, bool showScale)
{
	int w = width;
	int h = height;
	int b = 10;		// border around graph within the image
	if (w <= 20)
		w = nArrayLength + b*2;	// width of the image
	if (h <= 20)
		h = 220;

	int s = h - b*2;// size of graph height
	float xscale = 1.0;
	if (nArrayLength > 1)
		xscale = (w - b*2) / (float)(nArrayLength-1);	// horizontal scale
	IplImage *imageGraph;	// output image

	// Get the desired image to draw into.
	if (!imageDst) {
		// Create an RGB image for graphing the data
		imageGraph = cvCreateImage(cvSize(w,h), 8, 3);

		// Clear the image
		cvSet(imageGraph, WHITE);
	}
	else {
		// Draw onto the given image.
		imageGraph = imageDst;
	}
	if (!imageGraph) {
		std::cerr << "ERROR in drawUCharGraph(): Couldn't create image of " << w << " x " << h << std::endl;
		exit(1);
	}
	CvScalar colorGraph = getGraphColor();	// use a different color each time.

	// If the user didnt supply min & mav values, find them from the data, so we can draw it at full scale.
	if (minV == 0 && maxV == 0) {
		for (int i=0; i<nArrayLength; i++) {
			int v = arraySrc[i];
			if (v < minV)
				minV = v;
			if (v > maxV)
				maxV = v;
		}
	}
	int diffV = maxV - minV;
	if (diffV == 0)
		diffV = 1;	// Stop a divide-by-zero error
	float fscale = (float)s / (float)diffV;

	// Draw the horizontal & vertical axis
	int y0 = cvRound(minV*fscale);
	cvLine(imageGraph, cvPoint(b,h-(b-y0)), cvPoint(w-b, h-(b-y0)), BLACK);
	cvLine(imageGraph, cvPoint(b,h-(b)), cvPoint(b, h-(b+s)), BLACK);

	// Write the scale of the y axis
	CvFont font;
	cvInitFont(&font,CV_FONT_HERSHEY_PLAIN,0.55,0.7, 0,1,CV_AA);	// For OpenCV 1.1
	if (showScale) {
		//cvInitFont(&font,CV_FONT_HERSHEY_PLAIN,0.5,0.6, 0,1, CV_AA);	// For OpenCV 2.0
		CvScalar clr = GREY;
		char text[16];
		sprintf_s(text, sizeof(text)-1, "%.1f", maxV);
		cvPutText(imageGraph, text, cvPoint(1, b+4), &font, clr);
		// Write the scale of the x axis
		sprintf_s(text, sizeof(text)-1, "%d", (nArrayLength-1) );
		cvPutText(imageGraph, text, cvPoint(w-b+4-5*strlen(text), (h/2)+10), &font, clr);
	}

	// Draw the values
	CvPoint ptPrev = cvPoint(b,h-(b-y0));	// Start the lines at the 1st point.
	for (int i=0; i<nArrayLength; i++) {
		int y = cvRound((arraySrc[i] - minV) * fscale);	// Get the values at a bigger scale
		int x = cvRound(i * xscale);
		CvPoint ptNew = cvPoint(b+x, h-(b+y));
		cvLine(imageGraph, ptPrev, ptNew, colorGraph, 1, CV_AA);	// Draw a line from the previous point to the new point
		ptPrev = ptNew;
	}

	// Write the graph label, if desired
	if (graphLabel != NULL && strlen(graphLabel) > 0) {
		//cvInitFont(&font,CV_FONT_HERSHEY_PLAIN, 0.5,0.7, 0,1,CV_AA);
		cvPutText(imageGraph, graphLabel, cvPoint(30, 10), &font, CV_RGB(0,0,0));	// black text
	}

	return imageGraph;
}

// Display a graph of the given float array.
// If background is provided, it will be drawn into, for combining multiple graphs using drawFloatGraph().
// Set delay_ms to 0 if you want to wait forever until a keypress, or set it to 1 if you want it to delay just 1 millisecond.
void showFloatGraph(const char *name, const float *arraySrc, int nArrayLength, int delay_ms, IplImage *background)
{
#ifdef USE_HIGHGUI
	// Draw the graph
	IplImage *imageGraph = drawFloatGraph(arraySrc, nArrayLength, background);

	// Display the graph into a window
    cvNamedWindow( name );
    cvShowImage( name, imageGraph );

	cvWaitKey( 10 );		// Note that cvWaitKey() is required for the OpenCV window to show!
	cvWaitKey( delay_ms );	// Wait longer to make sure the user has seen the graph

	cvReleaseImage(&imageGraph);
#endif
}

// Display a graph of the given int array.
// If background is provided, it will be drawn into, for combining multiple graphs using drawIntGraph().
// Set delay_ms to 0 if you want to wait forever until a keypress, or set it to 1 if you want it to delay just 1 millisecond.
void showIntGraph(const char *name, const int *arraySrc, int nArrayLength, int delay_ms, IplImage *background)
{
#ifdef USE_HIGHGUI
	// Draw the graph
	IplImage *imageGraph = drawIntGraph(arraySrc, nArrayLength, background);

	// Display the graph into a window
    cvNamedWindow( name );
    cvShowImage( name, imageGraph );

	cvWaitKey( 10 );		// Note that cvWaitKey() is required for the OpenCV window to show!
	cvWaitKey( delay_ms );	// Wait longer to make sure the user has seen the graph

	cvReleaseImage(&imageGraph);
#endif
}

// Display a graph of the given unsigned char array.
// If background is provided, it will be drawn into, for combining multiple graphs using drawUCharGraph().
// Set delay_ms to 0 if you want to wait forever until a keypress, or set it to 1 if you want it to delay just 1 millisecond.
void showUCharGraph(const char *name, const uchar *arraySrc, int nArrayLength, int delay_ms, IplImage *background)
{
#ifdef USE_HIGHGUI
	// Draw the graph
	IplImage *imageGraph = drawUCharGraph(arraySrc, nArrayLength, background);

	// Display the graph into a window
    cvNamedWindow( name );
    cvShowImage( name, imageGraph );

	cvWaitKey( 10 );		// Note that cvWaitKey() is required for the OpenCV window to show!
	cvWaitKey( delay_ms );	// Wait longer to make sure the user has seen the graph

	cvReleaseImage(&imageGraph);
#endif
}

// Simple helper function to easily view an image, with an optional pause.
void showImage(const IplImage *img, int delay_ms, char *name)
{
#ifdef USE_HIGHGUI
	if (!name)
		name = "Image";
	cvNamedWindow(name, CV_WINDOW_AUTOSIZE);
	cvShowImage(name, img);
	cvWaitKey(delay_ms);
#endif
}