Added imagefilter() function by Pierre-Alain Joye (paj@pearfr.org). This

function allows negate, grayscale, brightness, contrast, colorize, selective blur,
Gaussian blur, edge detect, smooth, sharpen and emboss filters to be applied
on an image.

2 files changed, 487 insertions, 0 deletions

diff --git a/ext/gd/libgd/gd.c b/ext/gd/libgd/gd.c
index 0794ab5467..cc407d6cc3 100644
--- a/ext/gd/libgd/gd.c
+++ b/ext/gd/libgd/gd.c
@@ -3151,3 +3151,454 @@ gdAlphaOverlayColor( int src, int dst, int max )
 		return dst * src / max;
 	}
 }
+
+#ifndef HAVE_GET_TRUE_COLOR
+#define GET_PIXEL_FUNCTION(src)(src->trueColor?gdImageGetTrueColorPixel:gdImageGetPixel)
+#endif
+
+/* invert src image */
+int gdImageNegate(gdImagePtr src)
+{
+	int x, y;
+	int r,g,b,a;
+	int new_pxl, pxl;
+	typedef int (*FuncPtr)(gdImagePtr, int, int);
+	FuncPtr f;
+
+	if (src==NULL) {
+		return 0;
+	}
+    
+	f = GET_PIXEL_FUNCTION(src);
+
+	for (y=0; y<src->sy; ++y) {
+		for (x=0; x<src->sx; ++x) {
+			pxl = f (src, x, y);
+			r = gdImageRed(src, pxl);
+			g = gdImageGreen(src, pxl);
+			b = gdImageBlue(src, pxl);
+			a = gdImageAlpha(src, pxl);
+			
+			new_pxl = gdImageColorAllocateAlpha(src, 255-r, 255-g, 255-b, a);
+			if (new_pxl == -1) {
+				new_pxl = gdImageColorClosestAlpha(src, 255-r, 255-g, 255-b, a);
+			}
+			if ((y >= 0) && (y < src->sy)) {
+				gdImageSetPixel (src, x, y, new_pxl);
+			}
+		}
+	}
+	return 1;
+}
+
+/* Convert the image src to a grayscale image */
+int gdImageGrayScale(gdImagePtr src)
+{
+	int x, y;
+	int r,g,b,a;
+	int new_pxl, pxl;
+	typedef int (*FuncPtr)(gdImagePtr, int, int);
+	FuncPtr f;
+	f = GET_PIXEL_FUNCTION(src);
+
+	if (src==NULL) {
+		return 0;
+	}
+
+	for (y=0; y<src->sy; ++y) {
+		for (x=0; x<src->sx; ++x) {
+			pxl = f (src, x, y);
+			r = gdImageRed(src, pxl);
+			g = gdImageGreen(src, pxl);
+			b = gdImageBlue(src, pxl);
+			a = gdImageAlpha(src, pxl);
+			r = g = b = (int) (.299 * r + .587 * g + .114 * b);
+
+			new_pxl = gdImageColorAllocateAlpha(src, r, g, b, a);
+			if (new_pxl == -1) {
+				new_pxl = gdImageColorClosestAlpha(src, r, g, b, a);
+			}
+			if ((y >= 0) && (y < src->sy)) {
+				gdImageSetPixel (src, x, y, new_pxl);
+			}
+		}
+	}
+	return 1;
+}
+
+/* Set the brightness level <level> for the image src */
+int gdImageBrightness(gdImagePtr src, int brightness)
+{
+	int x, y;
+	int r,g,b,a;
+	int new_pxl, pxl;
+	typedef int (*FuncPtr)(gdImagePtr, int, int);
+	FuncPtr f;
+	f = GET_PIXEL_FUNCTION(src);
+
+	if (src==NULL || (brightness < -255 || brightness>255)) {
+		return 0;
+	}
+  
+	if (brightness==0) {
+		return 1;
+	}
+
+	for (y=0; y<src->sy; ++y) {
+		for (x=0; x<src->sx; ++x) {
+			pxl = f (src, x, y);
+			
+			r = gdImageRed(src, pxl);
+			g = gdImageGreen(src, pxl);
+			b = gdImageBlue(src, pxl);
+			a = gdImageAlpha(src, pxl);
+			
+			r = r + brightness;
+			g = g + brightness;
+			b = b + brightness;
+			
+			r = (r > 255)? 255 : ((r < 0)? 0:r);
+			g = (g > 255)? 255 : ((g < 0)? 0:g);
+			b = (b > 255)? 255 : ((b < 0)? 0:b);
+
+			new_pxl = gdImageColorAllocateAlpha(src, (int)r, (int)g, (int)b, a);
+			if (new_pxl == -1) {
+				new_pxl = gdImageColorClosestAlpha(src, (int)r, (int)g, (int)b, a);
+			}
+			if ((y >= 0) && (y < src->sy)) {
+				gdImageSetPixel (src, x, y, new_pxl);
+			}
+		}
+	}
+	return 1;
+}
+
+
+int gdImageContrast(gdImagePtr src, double contrast)
+{
+	int x, y;
+	int r,g,b,a;
+	double rf,gf,bf;
+	int new_pxl, pxl;
+	typedef int (*FuncPtr)(gdImagePtr, int, int);
+
+	FuncPtr f;
+	f = GET_PIXEL_FUNCTION(src);
+
+	if (src==NULL) {
+		return 0;
+	}
+	
+	contrast = (double)(100.0-80.0)/100.0;
+	contrast = contrast*contrast;
+	
+	for (y=0; y<src->sy; ++y) {
+		for (x=0; x<src->sx; ++x) {
+			pxl = f(src, x, y); 
+			
+			r = gdImageRed(src, pxl);
+			g = gdImageGreen(src, pxl);
+			b = gdImageBlue(src, pxl);
+			a = gdImageAlpha(src, pxl);
+
+			rf = (double)r/255.0;
+			rf = rf-0.5;
+			rf = rf*contrast;
+			rf = rf+0.5;
+			rf = rf*255.0;
+
+			bf = (double)b/255.0;
+			bf = bf-0.5;
+			bf = bf*contrast;
+			bf = bf+0.5;
+			bf = bf*255.0;
+      
+			gf = (double)g/255.0;
+			gf = gf-0.5;
+			gf = gf*contrast;
+			gf = gf+0.5;
+			gf = gf*255.0;
+
+			rf = (rf > 255.0)? 255.0 : ((rf < 0.0)? 0.0:rf);
+			gf = (gf > 255.0)? 255.0 : ((gf < 0.0)? 0.0:gf);
+			bf = (bf > 255.0)? 255.0 : ((bf < 0.0)? 0.0:bf);
+
+			new_pxl = gdImageColorAllocateAlpha(src, (int)rf, (int)gf, (int)bf, a);
+			if (new_pxl == -1) {
+				new_pxl = gdImageColorClosestAlpha(src, (int)rf, (int)gf, (int)bf, a);
+			}
+			if ((y >= 0) && (y < src->sy)) {
+				gdImageSetPixel (src, x, y, new_pxl);
+			}
+		}
+	}
+	return 1;
+}
+
+
+int gdImageColor(gdImagePtr src, int red, int green, int blue)
+{
+	int x, y;
+	int r,g,b,a;
+	int new_pxl, pxl;
+	typedef int (*FuncPtr)(gdImagePtr, int, int);
+	FuncPtr f;
+
+	if (src==NULL || (red<-255||red>255) || (green<-255||green>255) || (blue<-255||blue>255)) {
+		return 0;
+	}
+  
+	f = GET_PIXEL_FUNCTION(src);
+  
+	for (y=0; y<src->sy; ++y) {
+		for (x=0; x<src->sx; ++x) {
+			pxl = f(src, x, y); 
+			r = gdImageRed(src, pxl);
+			g = gdImageGreen(src, pxl);
+			b = gdImageBlue(src, pxl);
+			a = gdImageAlpha(src, pxl);
+
+			r = r + red;
+			g = g + green;
+			b = b + blue;
+
+			r = (r > 255)? 255 : ((r < 0)? 0:r);
+			g = (g > 255)? 255 : ((g < 0)? 0:g);
+			b = (b > 255)? 255 : ((b < 0)? 0:b);
+
+			new_pxl = gdImageColorAllocateAlpha(src, (int)r, (int)g, (int)b, a);
+			if (new_pxl == -1) {
+				new_pxl = gdImageColorClosestAlpha(src, (int)r, (int)g, (int)b, a);
+			}
+			if ((y >= 0) && (y < src->sy)) {
+				gdImageSetPixel (src, x, y, new_pxl);
+			}
+		}
+	}
+	return 1;
+}
+
+int gdImageConvolution(gdImagePtr src, float filter[3][3], float filter_div, float offset)
+{
+	int         x, y, i, j, new_a;
+	float       new_r, new_g, new_b;
+	int         new_pxl, pxl=0;
+	gdImagePtr  srcback;
+	typedef int (*FuncPtr)(gdImagePtr, int, int);
+	FuncPtr f;
+
+	if (src==NULL) {
+		return 0;
+	}
+
+	/* We need the orinal image with each safe neoghb. pixel */
+	srcback = gdImageCreateTrueColor (src->sx, src->sy);
+	gdImageCopy(srcback, src,0,0,0,0,src->sx,src->sy);
+  
+	if (srcback==NULL) {
+		return 0;
+	}
+
+	f = GET_PIXEL_FUNCTION(src);
+
+	for ( y=0; y<src->sy; y++) {
+		for(x=0; x<src->sx; x++) {
+			new_r = new_g = new_b = 0;
+			new_a = gdImageAlpha(srcback, pxl);
+			
+			for (j=0; j<3; j++) {
+				for (i=0; i<3; i++) {
+				        pxl = f(srcback, x-(3>>1)+i, y-(3>>1)+j); 
+					new_r += (float)gdImageRed(srcback, pxl) * filter[j][i];
+					new_g += (float)gdImageGreen(srcback, pxl) * filter[j][i];
+					new_b += (float)gdImageBlue(srcback, pxl) * filter[j][i];
+				}
+			}	
+			
+			new_r = (new_r/filter_div)+offset;
+			new_g = (new_g/filter_div)+offset;
+			new_b = (new_b/filter_div)+offset;
+
+			new_r = (new_r > 255.0)? 255.0 : ((new_r < 0.0)? 0.0:new_r);
+			new_g = (new_g > 255.0)? 255.0 : ((new_g < 0.0)? 0.0:new_g);
+			new_b = (new_b > 255.0)? 255.0 : ((new_b < 0.0)? 0.0:new_b);
+
+			new_pxl = gdImageColorAllocateAlpha(src, (int)new_r, (int)new_g, (int)new_b, new_a);
+			if (new_pxl == -1) {
+				new_pxl = gdImageColorClosestAlpha(src, (int)new_r, (int)new_g, (int)new_b, new_a);
+			}
+			if ((y >= 0) && (y < src->sy)) {
+				gdImageSetPixel (src, x, y, new_pxl);
+			}
+		}
+	}
+	gdImageDestroy(srcback); 
+	return 1; 
+}
+
+int gdImageSelectiveBlur( gdImagePtr src)
+{
+	int         x, y, i, j;
+	float       new_r, new_g, new_b;
+	int         new_pxl, cpxl, pxl, new_a=0;
+	float flt_r [3][3];
+	float flt_g [3][3];
+	float flt_b [3][3];
+	float flt_r_sum, flt_g_sum, flt_b_sum;
+
+	gdImagePtr srcback;
+	typedef int (*FuncPtr)(gdImagePtr, int, int);
+	FuncPtr f;
+
+	if (src==NULL) {
+		return 0;
+	}
+	
+	/* We need the orinal image with each safe neoghb. pixel */
+	srcback = gdImageCreateTrueColor (src->sx, src->sy);
+	gdImageCopy(srcback, src,0,0,0,0,src->sx,src->sy);
+  
+	if (srcback==NULL) {
+		return 0;
+	}
+
+	f = GET_PIXEL_FUNCTION(src);
+
+	for(y = 0; y<src->sy; y++) {
+		for (x=0; x<src->sx; x++) {
+		      flt_r_sum = flt_g_sum = flt_b_sum = 0.0;
+			cpxl = f(src, x, y); 
+
+			for (j=0; j<3; j++) {
+				for (i=0; i<3; i++) {
+					if ((j == 1) && (i == 1)) {
+						flt_r[1][1] = flt_g[1][1] = flt_b[1][1] = 0.5;
+					} else {
+						pxl = f(src, x-(3>>1)+i, y-(3>>1)+j); 
+						new_a = gdImageAlpha(srcback, pxl);
+
+						new_r = ((float)gdImageRed(srcback, cpxl)) - ((float)gdImageRed (srcback, pxl));
+						
+						if (new_r < 0.0) {
+							new_r = -new_r;
+						}	
+						if (new_r != 0) {
+							flt_r[j][i] = 1.0/new_r;
+						} else {
+							flt_r[j][i] = 1.0;
+						}	
+
+						new_g = ((float)gdImageGreen(srcback, cpxl)) - ((float)gdImageGreen(srcback, pxl));
+						
+						if (new_g < 0.0) {
+							new_g = -new_g;
+						}	
+						if (new_g != 0) {
+							flt_g[j][i] = 1.0/new_g;
+						} else {
+							flt_g[j][i] = 1.0;
+						}	
+
+						new_b = ((float)gdImageBlue(srcback, cpxl)) - ((float)gdImageBlue(srcback, pxl));
+
+						if (new_b < 0.0) {
+							new_b = -new_b;
+						}	
+						if (new_b != 0) {
+							flt_b[j][i] = 1.0/new_b;
+						} else {
+							flt_b[j][i] = 1.0;
+						}
+					}
+						
+					flt_r_sum += flt_r[j][i];
+					flt_g_sum += flt_g[j][i];
+					flt_b_sum += flt_b [j][i];
+				}
+			}
+      
+			for (j=0; j<3; j++) {
+				for (i=0; i<3; i++) {
+					if (flt_r_sum != 0.0) {
+						flt_r[j][i] /= flt_r_sum;
+					}	
+					if (flt_g_sum != 0.0) {
+						flt_g[j][i] /= flt_g_sum;
+					}	
+					if (flt_b_sum != 0.0) {
+						flt_b [j][i] /= flt_b_sum;
+					}	
+				}
+			}
+
+			new_r = new_g = new_b = 0.0;
+			
+			for (j=0; j<3; j++) {
+				for (i=0; i<3; i++) {
+					pxl = f(src, x-(3>>1)+i, y-(3>>1)+j);
+					new_r += (float)gdImageRed(srcback, pxl) * flt_r[j][i];
+					new_g += (float)gdImageGreen(srcback, pxl) * flt_g[j][i];
+					new_b += (float)gdImageBlue(srcback, pxl) * flt_b[j][i];
+				}
+			}
+
+			new_r = (new_r > 255.0)? 255.0 : ((new_r < 0.0)? 0.0:new_r);
+			new_g = (new_g > 255.0)? 255.0 : ((new_g < 0.0)? 0.0:new_g);
+			new_b = (new_b > 255.0)? 255.0 : ((new_b < 0.0)? 0.0:new_b);
+			new_pxl = gdImageColorAllocateAlpha(src, (int)new_r, (int)new_g, (int)new_b, new_a);
+			if (new_pxl == -1) {
+				new_pxl = gdImageColorClosestAlpha(src, (int)new_r, (int)new_g, (int)new_b, new_a);
+			}
+			if ((y >= 0) && (y < src->sy)) {
+				gdImageSetPixel (src, x, y, new_pxl);
+			}      
+		}
+	}
+	gdImageDestroy(srcback);
+	return 1;
+}
+
+int gdImageEdgeDetectQuick(gdImagePtr src)
+{
+	float filter[3][3] =	{{1.0,1.0,1.0},
+				{0.0,0.0,0.0},
+				{-1.0,-1.0,-1.0}};
+				
+	return gdImageConvolution(src, filter, 1, 127);
+}
+
+int gdImageGaussianBlur(gdImagePtr im)
+{
+	float filter[3][3] =	{{1.0,2.0,1.0},
+				{2.0,4.0,2.0},
+				{1.0,2.0,1.0}};
+	
+	return gdImageConvolution(im, filter, 16, 0); 
+}
+
+int gdImageEmboss(gdImagePtr im)
+{
+	float filter[3][3] =	{{-1.0,0.0,-1.0},
+				{0.0,4.0,0.0},
+				{-1.0,0.0,-1.0}};
+	
+	return gdImageConvolution(im, filter, 1, 127);
+}
+
+int gdImageMeanRemoval(gdImagePtr im)
+{
+	float filter[3][3] =	{{-1.0,-1.0,-1.0},
+				{-1.0,9.0,-1.0},
+				{-1.0,-1.0,-1.0}};
+	
+	return gdImageConvolution(im, filter, 1, 0);
+}
+
+int gdImageSmooth(gdImagePtr im, float weight)
+{
+	float filter[3][3] =	{{1.0,1.0,1.0},
+				{1.0,weight ,1.0},
+				{1.0,1.0,1.0}};
+	
+	return gdImageConvolution(im, filter, weight+8, 0);
+}
diff --git a/ext/gd/libgd/gd.h b/ext/gd/libgd/gd.h
index 21c3c5515b..4629cd9a59 100644
--- a/ext/gd/libgd/gd.h
+++ b/ext/gd/libgd/gd.h
@@ -517,6 +517,42 @@ void* gdDPExtractData(struct gdIOCtx* ctx, int *size);
 #define GD2_FMT_RAW             1
 #define GD2_FMT_COMPRESSED      2
 
+
+/* filters section 
+ *
+ * Negate the imag src, white becomes black,
+ * The red, green, and blue intensities of an image are negated.
+ * White becomes black, yellow becomes blue, etc.
+ */
+int gdImageNegate(gdImagePtr src);
+
+/* Convert the image src to a grayscale image */
+int gdImageGrayScale(gdImagePtr src);
+
+/* Set the brightness level <brightness> for the image src */
+int gdImageBrightness(gdImagePtr src, int brightness);
+
+/* Set the contrast level <contrast> for the image <src> */
+int gdImageContrast(gdImagePtr src, double contrast);
+
+/* Simply adds or substracts respectively red, green or blue to a pixel */
+int gdImageColor(gdImagePtr src, int red, int green, int blue);
+
+/* Image convolution by a 3x3 custom matrix */
+int gdImageConvolution(gdImagePtr src, float ft[3][3], float filter_div, float offset);
+
+int gdImageEdgeDetectQuick(gdImagePtr src);
+
+int gdImageGaussianBlur(gdImagePtr im);
+
+int gdImageSelectiveBlur( gdImagePtr src);
+
+int gdImageEmboss(gdImagePtr im);
+
+int gdImageMeanRemoval(gdImagePtr im);
+
+int gdImageSmooth(gdImagePtr im, float weight);
+
 /* Image comparison definitions */
 int gdImageCompare(gdImagePtr im1, gdImagePtr im2);