ximahist.cpp

信息隐藏中用于数字隐写的常用算法:LSB替换LSB匹配,包括随机的和排序的,以及对文件和文件夹进行操作,用CxImage类能快速读取各种格式的图象

			}
		}
	  }
	}
  }
  return true;
}
////////////////////////////////////////////////////////////////////////////////
// HistogramEqualize function by <dave> : dave(at)posortho(dot)com
bool CxImage::HistogramEqualize()
{
	if (!pDib) return false;

    int histogram[256];
	int map[256];
	int equalize_map[256];
    int x, y, i, j;
	RGBQUAD color;
	RGBQUAD	yuvClr;
	unsigned int YVal, high, low;

	memset( &histogram, 0, sizeof(int) * 256 );
	memset( &map, 0, sizeof(int) * 256 );
	memset( &equalize_map, 0, sizeof(int) * 256 );
 
     // form histogram
	for(y=0; y < head.biHeight; y++){
		info.nProgress = (long)(50*y/head.biHeight);
		if (info.nEscape) break;
		for(x=0; x < head.biWidth; x++){
			color = GetPixelColor( x, y );
			YVal = (unsigned int)RGB2GRAY(color.rgbRed, color.rgbGreen, color.rgbBlue);
			histogram[YVal]++;
		}
	}

	// integrate the histogram to get the equalization map.
	j = 0;
	for(i=0; i <= 255; i++){
		j += histogram[i];
		map[i] = j; 
	}

	// equalize
	low = map[0];
	high = map[255];
	if (low == high) return false;
	for( i = 0; i <= 255; i++ ){
		equalize_map[i] = (unsigned int)((((double)( map[i] - low ) ) * 255) / ( high - low ) );
	}

	// stretch the histogram
	if(head.biClrUsed == 0){ // No Palette
		for( y = 0; y < head.biHeight; y++ ){
			info.nProgress = (long)(50+50*y/head.biHeight);
			if (info.nEscape) break;
			for( x = 0; x < head.biWidth; x++ ){

				color = GetPixelColor( x, y );
				yuvClr = RGBtoYUV(color);

                yuvClr.rgbRed = (BYTE)equalize_map[yuvClr.rgbRed];

				color = YUVtoRGB(yuvClr);
				SetPixelColor( x, y, color );
			}
		}
	} else { // Palette
		for( i = 0; i < (int)head.biClrUsed; i++ ){

			color = GetPaletteColor((BYTE)i);
			yuvClr = RGBtoYUV(color);

            yuvClr.rgbRed = (BYTE)equalize_map[yuvClr.rgbRed];

			color = YUVtoRGB(yuvClr);
			SetPaletteColor( (BYTE)i, color );
		}
	}
	return true;
}
////////////////////////////////////////////////////////////////////////////////
// HistogramNormalize function by <dave> : dave(at)posortho(dot)com
bool CxImage::HistogramNormalize()
{
	if (!pDib) return false;

	int histogram[256];
	int threshold_intensity, intense;
	int x, y, i;
	unsigned int normalize_map[256];
	unsigned int high, low, YVal;

	RGBQUAD color;
	RGBQUAD	yuvClr;

	memset( &histogram, 0, sizeof( int ) * 256 );
	memset( &normalize_map, 0, sizeof( unsigned int ) * 256 );
 
     // form histogram
	for(y=0; y < head.biHeight; y++){
		info.nProgress = (long)(50*y/head.biHeight);
		if (info.nEscape) break;
		for(x=0; x < head.biWidth; x++){
			color = GetPixelColor( x, y );
			YVal = (unsigned int)RGB2GRAY(color.rgbRed, color.rgbGreen, color.rgbBlue);
			histogram[YVal]++;
		}
	}

	// find histogram boundaries by locating the 1 percent levels
	threshold_intensity = ( head.biWidth * head.biHeight) / 100;

	intense = 0;
	for( low = 0; low < 255; low++ ){
		intense += histogram[low];
		if( intense > threshold_intensity )	break;
	}

	intense = 0;
	for( high = 255; high != 0; high--){
		intense += histogram[ high ];
		if( intense > threshold_intensity ) break;
	}

	if ( low == high ){
		// Unreasonable contrast;  use zero threshold to determine boundaries.
		threshold_intensity = 0;
		intense = 0;
		for( low = 0; low < 255; low++){
			intense += histogram[low];
			if( intense > threshold_intensity )	break;
		}
		intense = 0;
		for( high = 255; high != 0; high-- ){
			intense += histogram [high ];
			if( intense > threshold_intensity )	break;
		}
	}
	if( low == high ) return false;  // zero span bound

	// Stretch the histogram to create the normalized image mapping.
	for(i = 0; i <= 255; i++){
		if ( i < (int) low ){
			normalize_map[i] = 0;
		} else {
			if(i > (int) high)
				normalize_map[i] = 255;
			else
				normalize_map[i] = ( 255 - 1) * ( i - low) / ( high - low );
		}
	}

	// Normalize
	if( head.biClrUsed == 0 ){
		for( y = 0; y < head.biHeight; y++ ){
			info.nProgress = (long)(50+50*y/head.biHeight);
			if (info.nEscape) break;
			for( x = 0; x < head.biWidth; x++ ){

				color = GetPixelColor( x, y );
				yuvClr = RGBtoYUV( color );

                yuvClr.rgbRed = (BYTE)normalize_map[yuvClr.rgbRed];

				color = YUVtoRGB( yuvClr );
				SetPixelColor( x, y, color );
			}
		}
	} else {
		for(i = 0; i < (int)head.biClrUsed; i++){

			color = GetPaletteColor( (BYTE)i );
			yuvClr = RGBtoYUV( color );

            yuvClr.rgbRed = (BYTE)normalize_map[yuvClr.rgbRed];

			color = YUVtoRGB( yuvClr );
 			SetPaletteColor( (BYTE)i, color );
		}
	}
	return true;
}
////////////////////////////////////////////////////////////////////////////////
// HistogramLog function by <dave> : dave(at)posortho(dot)com
bool CxImage::HistogramLog()
{
	if (!pDib) return false;

	//q(i,j) = 255/log(1 + |high|) * log(1 + |p(i,j)|);
    int x, y, i;
	RGBQUAD color;
	RGBQUAD	yuvClr;

	unsigned int YVal, high = 1;

    // Find Highest Luminance Value in the Image
	if( head.biClrUsed == 0 ){ // No Palette
		for(y=0; y < head.biHeight; y++){
			info.nProgress = (long)(50*y/head.biHeight);
			if (info.nEscape) break;
			for(x=0; x < head.biWidth; x++){
				color = GetPixelColor( x, y );
				YVal = (unsigned int)RGB2GRAY(color.rgbRed, color.rgbGreen, color.rgbBlue);
				if (YVal > high ) high = YVal;
			}
		}
	} else { // Palette
		for(i = 0; i < (int)head.biClrUsed; i++){
			color = GetPaletteColor((BYTE)i);
			YVal = (unsigned int)RGB2GRAY(color.rgbRed, color.rgbGreen, color.rgbBlue);
			if (YVal > high ) high = YVal;
		}
	}

	// Logarithm Operator
	double k = 255.0 / ::log( 1.0 + (double)high );
	if( head.biClrUsed == 0 ){
		for( y = 0; y < head.biHeight; y++ ){
			info.nProgress = (long)(50+50*y/head.biHeight);
			if (info.nEscape) break;
			for( x = 0; x < head.biWidth; x++ ){

				color = GetPixelColor( x, y );
				yuvClr = RGBtoYUV( color );
                
				yuvClr.rgbRed = (BYTE)(k * ::log( 1.0 + (double)yuvClr.rgbRed ) );

				color = YUVtoRGB( yuvClr );
				SetPixelColor( x, y, color );
			}
		}
	} else {
		for(i = 0; i < (int)head.biClrUsed; i++){

			color = GetPaletteColor( (BYTE)i );
			yuvClr = RGBtoYUV( color );

            yuvClr.rgbRed = (BYTE)(k * ::log( 1.0 + (double)yuvClr.rgbRed ) );
			
			color = YUVtoRGB( yuvClr );
 			SetPaletteColor( (BYTE)i, color );
		}
	}
 
	return true;
}

////////////////////////////////////////////////////////////////////////////////
// HistogramRoot function by <dave> : dave(at)posortho(dot)com
bool CxImage::HistogramRoot()
{
	if (!pDib) return false;
	//q(i,j) = sqrt(|p(i,j)|);

    int x, y, i;
	RGBQUAD color;
	RGBQUAD	 yuvClr;
	double	dtmp;
	unsigned int YVal, high = 1;

     // Find Highest Luminance Value in the Image
	if( head.biClrUsed == 0 ){ // No Palette
		for(y=0; y < head.biHeight; y++){
			info.nProgress = (long)(50*y/head.biHeight);
			if (info.nEscape) break;
			for(x=0; x < head.biWidth; x++){
				color = GetPixelColor( x, y );
				YVal = (unsigned int)RGB2GRAY(color.rgbRed, color.rgbGreen, color.rgbBlue);
				if (YVal > high ) high = YVal;
			}
		}
	} else { // Palette
		for(i = 0; i < (int)head.biClrUsed; i++){
			color = GetPaletteColor((BYTE)i);
			YVal = (unsigned int)RGB2GRAY(color.rgbRed, color.rgbGreen, color.rgbBlue);
			if (YVal > high ) high = YVal;
		}
	}

	// Root Operator
	double k = 128.0 / ::log( 1.0 + (double)high );
	if( head.biClrUsed == 0 ){
		for( y = 0; y < head.biHeight; y++ ){
			info.nProgress = (long)(50+50*y/head.biHeight);
			if (info.nEscape) break;
			for( x = 0; x < head.biWidth; x++ ){

				color = GetPixelColor( x, y );
				yuvClr = RGBtoYUV( color );

				dtmp = k * ::sqrt( (double)yuvClr.rgbRed );
				if ( dtmp > 255.0 )	dtmp = 255.0;
				if ( dtmp < 0 )	dtmp = 0;
                yuvClr.rgbRed = (BYTE)dtmp;

				color = YUVtoRGB( yuvClr );
				SetPixelColor( x, y, color );
			}
		}
	} else {
		for(i = 0; i < (int)head.biClrUsed; i++){

			color = GetPaletteColor( (BYTE)i );
			yuvClr = RGBtoYUV( color );

			dtmp = k * ::sqrt( (double)yuvClr.rgbRed );
			if ( dtmp > 255.0 )	dtmp = 255.0;
			if ( dtmp < 0 ) dtmp = 0;
            yuvClr.rgbRed = (BYTE)dtmp;

			color = YUVtoRGB( yuvClr );
 			SetPaletteColor( (BYTE)i, color );
		}
	}
 
	return true;
}
////////////////////////////////////////////////////////////////////////////////
#endif