How can I modify the function of openexr

dear all,

As title, I want to modify the function of openexr.
I try to modify the source code of ImfPizCompressor.cpp, only add one 
line: printf("start wavelet encoding\n");, and then build the openexr 
library.
But after I build the openexr library and write an test code, the 
sentence that I expect to output is not output.
So, whether the result means that I don't modify the function 
successfully?
And, how can I modify the function of openexr?

The test codes I use are below:
#include <iostream>
#include <tchar.h>
#include <string.h>
#include <fstream>
#include <math.h>

#define OPENEXR_DLL

#include <ImfOutputFile.h>
#include <ImfInputFile.h>
#include <ImfChannelList.h>
#include <ImfArray.h>
#include <Iex.h>
#include <half.h>
#include <ImfNamespace.h>
#include "ImfHeader.h"

using namespace std;
using namespace Imf;
using namespace Imath;

int _tmain(int argc, _TCHAR* argv[])
{
	int width = 0;
	int height = 0;
	Array2D<half> rUncompressionPixels;
	Array2D<half> gUncompressionPixels;
	Array2D<half> bUncompressionPixels;

	printf("\nOpenEXR Test Piz Compression\n");

	InputFile fileUncompression 
("OpenEXR_uncompression_1x6_red.exr");
	//InputFile file ("OpenEXR_piz_1x6_red.exr");

	Box2i dw = fileUncompression.header().dataWindow();
	width = dw.max.x - dw.min.x + 1;
	height = dw.max.y - dw.min.y + 1;

	rUncompressionPixels.resizeErase (height, width);
	gUncompressionPixels.resizeErase (height, width);
	bUncompressionPixels.resizeErase (height, width);

	FrameBuffer frameBuffer;

	frameBuffer.insert ("R",																				
// name
		                Slice (HALF,																		
// type
						       (char *) 
(&rUncompressionPixels[0][0] - dw.min.x - dw.min.y * width),		
// base
							   sizeof 
(rUncompressionPixels[0][0]) * 1,										
// xStride
							   sizeof 
(rUncompressionPixels[0][0]) * width,									
// yStride
							   1, 1,																		
// fillValue
							   0.0));
	frameBuffer.insert ("G",
		                Slice (HALF,
						       (char *) 
(&gUncompressionPixels[0][0] - dw.min.x - dw.min.y * width),
							   sizeof 
(gUncompressionPixels[0][0]) * 1,
							   sizeof 
(gUncompressionPixels[0][0]) * width,
							   1, 1,
							   0.0));
	frameBuffer.insert ("B",
		                Slice (HALF,
						       (char *) 
(&bUncompressionPixels[0][0] - dw.min.x - dw.min.y * width),
							   sizeof 
(bUncompressionPixels[0][0]) * 1,
							   sizeof 
(bUncompressionPixels[0][0]) * width,
							   1, 1,
							   0.0));

	fileUncompression.setFrameBuffer (frameBuffer);
	fileUncompression.readPixels (dw.min.y, dw.max.y);

	// apply Piz compression
	Header header (width, height);
	header.channels().insert ("R", Channel (HALF));
	header.channels().insert ("G", Channel (HALF));
	header.channels().insert ("B", Channel (HALF));

	header.compression() = Imf::PIZ_COMPRESSION;
	OutputFile file ("OpenEXR_PizCompression_1x6_red.exr", header);

	file.setFrameBuffer (frameBuffer);
	file.writePixels (height);

	// output another images applied by Piz compression
	for (int i = 0;i < height;i++)
	{
		for (int j = 0; j < width;j++)
		{
			rUncompressionPixels[i][j] = 0;
			gUncompressionPixels[i][j] = 1;
			bUncompressionPixels[i][j] = 0;
		}
		cout << endl;
	}

	OutputFile file_green ("OpenEXR_PizCompression_1x6_green.exr", 
header);

	file_green.setFrameBuffer (frameBuffer);
	file_green.writePixels (height);

	printf("\n - Program finished -");
    printf("\n***********************************\n");

    system("pause");
    return 0;
}


yan
2014.11.27