shithub: ifilter

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major refactoring

	- Code factorization to limit individual programs to the algorithm implementation
	- Added helper functions
	- Moved target output to an image folder under bin

--- a/README

+++ b/README

@@ -9,7 +9,7 @@

 --------

 cfilter implements basic color filters.

-Usage: cfilter [-f factor] [grayscale|sepia|invert|shade|tint]

+Usage: image/cfilter -f grayscale|sepia|invert|shade|tint [-r ratio]

 Available filters are:

 - grayscale

@@ -18,22 +18,32 @@

 - shade(1)

 - tint(1)

-1: these filters use the factor argument

+1: these filters use the ratio argument to determine the transformation ratio.

 blur:

 -----

 blur implements blurring algorithms.

-Usage: blur [-s size] [box|pixelate]

+Usage: image/blur -f box|gaussian [-s size]

 Available filters are:

 - box: 3x3 box blur

-- gaussian: Gaussian blur using `-s` as the convolution kernel radius (ie kernel will be a matrix r*r with r=2*size+1)

-- pixelate: a simple pixelation filter using `-s` argument as pixel size

+- gaussian: Gaussian blur using `-s` as the convolution kernel radius (ie kernel will be a matrix r*r with r=2*s+1)

+pixelate:

+---------

+pixelate implements a pixelation algorithm.

+

+Usage: image/pixelate [-s size]

+size is the output pixel size (defaults to 8)

+

 dither:

 -------

 Floyd-Steinberg dithering algorithm.

-Usage: dither

+Usage: image/dither

+

+--

+Author: phil9

+License: MIT

--- /dev/null

+++ b/a.h

@@ -1,0 +1,18 @@

+#include <u.h>

+#include <libc.h>

+#include <draw.h>

+#include <memdraw.h>

+

+typedef uchar*(*filterfn)(uchar*, int, int, int);

+

+void	applyfilter(const char*, filterfn);

+int		clamp(int);

+uchar*	eallocbuf(ulong);

+

+enum

+{

+	Cblue,

+	Cgreen,

+	Cred,

+	Calpha,

+};

--- a/blur.c

+++ b/blur.c

@@ -1,26 +1,24 @@

-#include <u.h>

-#include <libc.h>

-#include <draw.h>

-#include <memdraw.h>

-

+#include "a.h"

+	

 typedef struct Filter Filter;

-int size;

 struct Filter

 {

 	const char *name;

-	uchar* (*filter)(uchar *data, int w, int h, int depth);

+	filterfn filter;

 };

+int size;

+

 uchar*

 box(uchar *data, int w, int h, int depth)

 {

 	uchar *out;

-	int x, y, c, s;

+	int n, x, y, c, s;

-	out = malloc(depth*w*h*sizeof(uchar));

-	if(out == nil)

-		return nil;

+	n = depth*w*h*sizeof(uchar);

+	out = eallocbuf(n);

+	memmove(out, data, n);

 	/* box blur is not defined for edge points */

 	for(y = 1; y < h - 1; y++){

 		for(x = 1; x < w - 1; x++){

@@ -44,44 +42,6 @@

 }

 uchar*

-pixelate(uchar *data, int w, int h, int depth)

-{

-	uchar *out;

-	int x, y, ox, oy, oi, sr, sg, sb;

-

-	if(size < 0)

-		sysfatal("pixelate filter needs a size argument");

-	out = malloc(depth*w*h*sizeof(uchar));

-	if(out == nil)

-		return nil;

-	for(y = 0; y < h; y += size){

-		for(x = 0; x < w; x += size){

-			sr = sg = sb = 0;

-			for(oy = y; oy < y+size; oy++){

-				for(ox = x; ox < x+size; ox++){

-					oi = (ox + w * oy) * depth;

-					sr += data[oi + 0]*data[oi + 0];

-					sg += data[oi + 1]*data[oi + 0];

-					sb += data[oi + 2]*data[oi + 0];

-				}

-			}

-			sr = sqrt(sr/(size*size));

-			sg = sqrt(sg/(size*size));

-			sb = sqrt(sb/(size*size));

-			for(oy = y; oy < y+size; oy++){

-				for(ox = x; ox < x+size; ox++){

-					oi = (ox + w * oy) * depth;

-					out[oi + 0] = sr;

-					out[oi + 1] = sg;

-					out[oi + 2] = sb;

-				}

-			}

-		}

-	}

-	return out;

-}

-

-uchar*

 gaussian(uchar *data, int w, int h, int depth)

 {

 	const double E = 2.7182818284590452354;

@@ -92,9 +52,9 @@

 	if(size < 0)

 		sysfatal("gaussian filter needs a size argument");

-	out = malloc(depth*w*h*sizeof(uchar));

-	if(out == nil)

-		return nil;

+	n = depth*w*h*sizeof(uchar);

+	out = eallocbuf(n);

+	memmove(out, data, n);

 	σ = (double)size / 2.0;

 	kw = 2 * size + 1;

 	k = malloc(kw*kw*sizeof(double));

@@ -141,13 +101,12 @@

 void

 usage(void)

 {

-	fprint(2, "usage: %s [-s size] [box|gaussian|pixelate]\n", argv0);

+	fprint(2, "usage: %s -f box|gaussian [-s size]\n", argv0);

 	exits("usage");

 }

 static Filter filters[] = {

 	{ "box", box },

-	{ "pixelate", pixelate },

 	{ "gaussian", gaussian },

 };

@@ -154,14 +113,22 @@

 void

 main(int argc, char *argv[])

 {

-	Memimage *o, *i;

-	int w, h, n;

-	uchar *buf, *out;

 	Filter *f;

+	char *fname;

+	int i;

-	size = -1;

+	size = 2;

 	f = nil;

 	ARGBEGIN{

+	case 'f':

+		fname = EARGF(usage());

+		for(i=0; i<nelem(filters); i++){

+			if(strcmp(fname, filters[i].name)==0){

+				f = filters+i;

+				break;

+			}

+		}

+		break;

 	case 's':

 		size = atoi(EARGF(usage()));

 		break;

@@ -169,38 +136,7 @@

 		usage();

 		break;

 	}ARGEND;

-	if(argc!=1)

-		usage();

-	for(n=0; n<nelem(filters); n++){

-		if(strcmp(*argv, filters[n].name)==0){

-			f = filters+n;

-			break;

-		}

-	}

 	if(f==nil)

 		usage();

-	if(memimageinit()<0)

-		sysfatal("memimageinit: %r");

-	o = readmemimage(0);

-	if(o==nil)

-		sysfatal("readmemimage: %r");

-	i = allocmemimage(rectsubpt(o->r, o->r.min), XRGB32);

-	memimagedraw(i, i->r, o, o->r.min, nil, ZP, S);

-	freememimage(o);

-	w = Dx(i->r);

-	h = Dy(i->r);

-	n = 4*w*h*sizeof(uchar);

-	buf = malloc(n);

-	if(buf==nil)

-		sysfatal("malloc: %r");

-	if(unloadmemimage(i, i->r, buf, n)<0)

-		sysfatal("unloadmemimage: %r");

-	freememimage(i);

-	out = f->filter(buf, w, h, 4);

-	if(out == nil)

-		sysfatal("filter '%s' failed: %r", f->name);

-	print("   x8r8g8b8 %11d %11d %11d %11d ", 0, 0, w, h);

-	write(1, out, n);

-	exits(nil);

+	applyfilter(f->name, f->filter);

 }

-

--- a/cfilter.c

+++ b/cfilter.c

@@ -1,66 +1,88 @@

-#include <u.h>

-#include <libc.h>

-#include <draw.h>

-#include <memdraw.h>

+#include "a.h"

-#define MIN(x,y) ((x)<(y)?(x):(y))

-

 typedef struct Filter Filter;

 struct Filter

 {

 	const char *name;

-	void (*filter)(uchar[3], float);

+	filterfn f;

 };

-void

-grayscale(uchar p[3], float)

+float ratio;

+

+uchar*

+grayscale(uchar* data, int w, int h, int depth)

 {

-	uchar v = 0.2126*p[2] + 0.7152*p[1] + 0.0722*p[0];

-	p[0] = p[1] = p[2] = v;

+	uchar v;

+	int i;

+

+	for(i = 0; i < w*h*depth; i += 4){

+		v = 0.2126*data[i+Cred] + 0.7152*data[i+Cgreen] + 0.0722*data[i+Cblue];

+		data[i+Cred] = data[i+Cgreen] = data[i+Cblue] = v;

+	}

+	return data;

 }

-void

-sepia(uchar p[3], float)

+uchar*

+sepia(uchar* data, int w, int h, int depth)

 {

 	float r, g, b;

+	int i;

-	r = 0.393*p[2] + 0.769*p[1] + 0.189*p[0];

-	g = 0.349*p[2] + 0.686*p[1] + 0.168*p[0];

-	b = 0.272*p[2] + 0.534*p[1] + 0.131*p[0];

-	p[2] = MIN(r, 255);

-	p[1] = MIN(g, 255);

-	p[0] = MIN(b, 255);

+	for(i = 0; i < w*h*depth; i += 4){

+		r = 0.393*data[i+Cred] + 0.769*data[i+Cgreen] + 0.189*data[i+Cblue];

+		g = 0.349*data[i+Cred] + 0.686*data[i+Cgreen] + 0.168*data[i+Cblue];

+		b = 0.272*data[i+Cred] + 0.534*data[i+Cgreen] + 0.131*data[i+Cblue];

+		data[i+Cred]   = clamp(r);

+		data[i+Cgreen] = clamp(g);

+		data[i+Cblue]  = clamp(b);

+	}

+	return data;

 }

-void

-invert(uchar p[3], float)

+uchar*

+invert(uchar* data, int w, int h, int depth)

 {

-	p[0] = 255 - p[0];

-	p[1] = 255 - p[1];

-	p[2] = 255 - p[2];

+	int i;

+

+	for(i = 0; i < w*h*depth; i += 4){

+		data[i+Cred]   = 255 - data[i+Cred];

+		data[i+Cgreen] = 255 - data[i+Cgreen];

+		data[i+Cblue]  = 255 - data[i+Cblue];

+	}

+	return data;

 }

-void

-shade(uchar p[3], float factor)

+uchar*

+shade(uchar* data, int w, int h, int depth)

 {

-	p[0] = p[0] * (1 - factor);

-	p[1] = p[1] * (1 - factor);

-	p[2] = p[2] * (1 - factor);

+	int i;

+

+	for(i = 0; i < w*h*depth; i += 4){

+		data[i+Cred]   *= (1 - ratio);

+		data[i+Cgreen] *= (1 - ratio);

+		data[i+Cblue]  *= (1 - ratio);

+	}

+	return data;

 }

-void

-tint(uchar p[3], float factor)

+uchar*

+tint(uchar* data, int w, int h, int depth)

 {

-	p[0] = p[0] + (255.0 - p[0]) * factor;

-	p[1] = p[1] + (255.0 - p[1]) * factor;

-	p[2] = p[2] + (255.0 - p[2]) * factor;

+	int i;

+

+	for(i = 0; i < w*h*depth; i += 4){

+		data[i+Cred]   += (255 - data[i+Cred]) * ratio;

+		data[i+Cgreen] += (255 - data[i+Cgreen]) * ratio;

+		data[i+Cblue]  += (255 - data[i+Cblue]) * ratio;

+	}

+	return data;

 }

 void

 usage(void)

 {

-	fprint(2, "usage: %s [-f factor] [grayscale|sepia|invert|shade|tint]\n", argv0);

+	fprint(2, "usage: %s -f grayscale|sepia|invert|shade|tint [-r ratio]\n", argv0);

 	exits("usage");

 }

@@ -72,72 +94,37 @@

 	{ "tint", tint },

 };

-int

-isalpha(ulong chan)

-{

-	ulong t;

-

-	for(t = chan; t; t >>= 8)

-		if(TYPE(t) == CAlpha)

-			return 1;

-	return 0;

-}

-

 void

 main(int argc, char *argv[])

 {

-	Memimage *o, *i;

-	int w, h, p, n, a;

-	uchar *buf;

 	Filter *f;

-	float factor;

+	char *fname;

+	int n;

 	f = nil;

-	factor = 0.0;

+	ratio = 0.0;

 	ARGBEGIN{

 	case 'f':

-		factor = (float)atof(EARGF(usage()));

+		fname = EARGF(usage());

+		for(n=0; n<nelem(filters); n++){

+			if(strcmp(fname, filters[n].name)==0){

+				f = filters+n;

+				break;

+			}

+		}

 		break;

+	case 'r':

+		ratio = (float)atof(EARGF(usage()));

+		break;

 	default:

 		usage();

 		break;

 	}ARGEND;

-	if(argc!=1)

-		usage();

-	for(n=0; n<nelem(filters); n++){

-		if(strcmp(*argv, filters[n].name)==0){

-			f = filters+n;

-			break;

-		}

-	}

 	if(f==nil)

 		usage();

-	if(factor<0.0 || factor>1.0){

-		fprint(2, "factor should be between 0.0 and 1.0\n");

-		exits("invalid factor");

+	if(ratio<0.0 || ratio>1.0){

+		fprint(2, "ratio should be between 0.0 and 1.0\n");

+		exits("invalid ratio");

 	}

-	if(memimageinit()<0)

-		sysfatal("memimageinit: %r");

-	o = readmemimage(0);

-	if(o==nil)

-		sysfatal("readmemimage: %r");

-	a = isalpha(o->chan);

-	i = allocmemimage(o->r, a ? ARGB32 : XRGB32);

-	memimagedraw(i, i->r, o, o->r.min, nil, ZP, S);

-	freememimage(o);

-	w = Dx(i->r);

-	h = Dy(i->r);

-	n = 4*w*h*sizeof(uchar);

-	buf = malloc(n);

-	if(buf==nil)

-		sysfatal("malloc: %r");

-	if(unloadmemimage(i, i->r, buf, n)<0)

-		sysfatal("unloadmemimage: %r");

-	freememimage(i);

-	for(p = 0; p < n; p+=4)

-		f->filter(buf+p, factor);

-	print("   %c8r8g8b8 %11d %11d %11d %11d ", a ? 'a' : 'x', 0, 0, w, h);

-	write(1, buf, n);

-	exits(nil);

+	applyfilter(f->name, f->f);

 }

-

--- /dev/null

+++ b/common.c

@@ -1,0 +1,66 @@

+#include "a.h"

+

+int

+isalpha(ulong chan)

+{

+	ulong t;

+

+	for(t = chan; t; t >>= 8)

+		if(TYPE(t) == CAlpha)

+			return 1;

+	return 0;

+}

+

+void

+applyfilter(const char *fname, filterfn f)

+{

+	Memimage *o, *i;

+	int w, h, n, a;

+	uchar *buf, *out;

+

+	if(memimageinit()<0)

+		sysfatal("memimageinit: %r");

+	o = readmemimage(0);

+	if(o==nil)

+		sysfatal("readmemimage: %r");

+	a = isalpha(o->chan);

+	i = allocmemimage(rectsubpt(o->r, o->r.min), a ? ARGB32 : XRGB32);

+	memimagedraw(i, i->r, o, o->r.min, nil, ZP, S);

+	freememimage(o);

+	w = Dx(i->r);

+	h = Dy(i->r);

+	n = 4*w*h*sizeof(uchar);

+	buf = malloc(n);

+	if(buf==nil)

+		sysfatal("malloc: %r");

+	if(unloadmemimage(i, i->r, buf, n)<0)

+		sysfatal("unloadmemimage: %r");

+	freememimage(i);

+	out = f(buf, w, h, 4);

+	if(out == nil)

+		sysfatal("%s failed: %r", fname);

+	print("   %c8r8g8b8 %11d %11d %11d %11d ", a ? 'a' : 'x', 0, 0, w, h);

+	write(1, out, n);

+	exits(nil);

+}

+

+int

+clamp(int n)

+{

+	if(n < 0)

+		n = 0;

+	else if(n > 255)

+		n = 255;

+	return n;

+}

+

+uchar*

+eallocbuf(ulong s)

+{

+	uchar *p;

+

+	p = malloc(s);

+	if(p == nil)

+		sysfatal("malloc: %r");

+	return p;

+}

--- a/dither.c

+++ b/dither.c

@@ -1,18 +1,5 @@

-#include <u.h>

-#include <libc.h>

-#include <draw.h>

-#include <memdraw.h>

+#include "a.h"

-int

-clamp(int n)

-{

-	if(n < 0)

-		n = 0;

-	else if(n > 255)

-		n = 255;

-	return n;

-}

-

 uchar*

 dither(uchar *data, int w, int h, int depth)

 {

@@ -21,11 +8,9 @@

 	uchar *out;

 	int x, y, c, o, n, q;

-	out = malloc(depth*w*h*sizeof(uchar));

-	if(out == nil)

-		return nil;

-	for(y = 0; y < depth*w*h; y++)

-		out[y] = data[y];

+	n = depth*w*h*sizeof(uchar);

+	out = eallocbuf(n);

+	memmove(out, data, n);

 	for(y = 0; y < h; y++){

 		for(x = 0; x < w; x++){

 			for(c = 0; c < 3; c++){ /* B G R */

@@ -55,37 +40,10 @@

 void

 main(int argc, char *argv[])

 {

-	Memimage *o, *i;

-	int w, h, n;

-	uchar *buf, *out;

-

 	ARGBEGIN{

 	default:

 		usage();

 		break;

 	}ARGEND;

-	if(memimageinit()<0)

-		sysfatal("memimageinit: %r");

-	o = readmemimage(0);

-	if(o==nil)

-		sysfatal("readmemimage: %r");

-	i = allocmemimage(rectsubpt(o->r, o->r.min), XRGB32);

-	memimagedraw(i, i->r, o, o->r.min, nil, ZP, S);

-	freememimage(o);

-	w = Dx(i->r);

-	h = Dy(i->r);

-	n = 4*w*h*sizeof(uchar);

-	buf = malloc(n);

-	if(buf==nil)

-		sysfatal("malloc: %r");

-	if(unloadmemimage(i, i->r, buf, n)<0)

-		sysfatal("unloadmemimage: %r");

-	freememimage(i);

-	out = dither(buf, w, h, 4);

-	if(out == nil)

-		sysfatal("dither failed: %r");

-	print("   x8r8g8b8 %11d %11d %11d %11d ", 0, 0, w, h);

-	write(1, out, n);

-	exits(nil);

+	applyfilter("dither", dither);

 }

-

--- a/mkfile

+++ b/mkfile

@@ -1,10 +1,17 @@

 </$objtype/mkfile

-BIN=/$objtype/bin

+BIN=/$objtype/bin/image

 CFLAGS=-FTVw

-TARG=cfilter blur dither

+TARG=cfilter pixelate blur dither

+HFILES=a.h

+OFILES=common.$O

 default:V: all

 </sys/src/cmd/mkmany

+

+install:V:

+	mkdir -p $BIN

+	for(i in $TARG)

+		mk $MKFLAGS $i.install

--- /dev/null

+++ b/pixelate.c

@@ -1,0 +1,63 @@

+#include "a.h"

+

+int size;

+

+uchar*

+pixelate(uchar *data, int w, int h, int depth)

+{

+	uchar *out;

+	int x, y, ox, oy, oi, sr, sg, sb;

+

+	if(size < 0)

+		sysfatal("pixelate filter needs a size argument");

+	out = malloc(depth*w*h*sizeof(uchar));

+	if(out == nil)

+		return nil;

+	for(y = 0; y < h; y += size){

+		for(x = 0; x < w; x += size){

+			sr = sg = sb = 0;

+			for(oy = y; oy < y+size; oy++){

+				for(ox = x; ox < x+size; ox++){

+					oi = (ox + w * oy) * depth;

+					sr += data[oi + 0]*data[oi + 0];

+					sg += data[oi + 1]*data[oi + 0];

+					sb += data[oi + 2]*data[oi + 0];

+				}

+			}

+			sr = sqrt(sr/(size*size));

+			sg = sqrt(sg/(size*size));

+			sb = sqrt(sb/(size*size));

+			for(oy = y; oy < y+size; oy++){

+				for(ox = x; ox < x+size; ox++){

+					oi = (ox + w * oy) * depth;

+					out[oi + 0] = sr;

+					out[oi + 1] = sg;

+					out[oi + 2] = sb;

+				}

+			}

+		}

+	}

+	return out;

+}

+

+void

+usage(void)

+{

+	fprint(2, "usage: %s [-s size] [box|gaussian|pixelate]\n", argv0);

+	exits("usage");

+}

+

+void

+main(int argc, char *argv[])

+{

+	size = 8;

+	ARGBEGIN{

+	case 's':

+		size = atoi(EARGF(usage()));

+		break;

+	default:

+		usage();

+		break;

+	}ARGEND;

+	applyfilter("pixelate", pixelate);

+}