/*
* img2twit Image to short text message encoder/decoder
* Copyright (c) 2009 Sam Hocevar <sam@hocevar.net>
* All Rights Reserved
*
* This program is free software. It comes without any warranty, to
* the extent permitted by applicable law. You can redistribute it
* and/or modify it under the terms of the Do What The Fuck You Want
* To Public License, Version 2, as published by Sam Hocevar. See
* http://sam.zoy.org/wtfpl/COPYING for more details.
*/
/* TODO:
* - remove the complicated stuff from get_point/set_point, it's only
* the final packing that really matters.
*/
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Delaunay_triangulation_2.h>
#include <CGAL/natural_neighbor_coordinates_2.h>
#include <pipi.h>
#include "../genethumb/mygetopt.h"
/*
* Format-dependent settings. Change this and you risk making all other
* generated strings unusable.
*/
/* Printable ASCII (except space) */
#define RANGE_ASCII 0x0021, 0x007f
/* CJK Unified Ideographs */
#define RANGE_CJK 0x4e00, 0x9fa6
//0x2e80, 0x2e9a, 0x2e9b, 0x2ef4, /* CJK Radicals Supplement */
//0x2f00, 0x2fd6, /* Kangxi Radicals */
//0x3400, 0x4db6, /* CJK Unified Ideographs Extension A */
//0xac00, 0xd7a4, /* Hangul Syllables -- Korean, not Chinese */
//0xf900, 0xfa2e, 0xfa30, 0xfa6b, 0xfa70, 0xfada, /* CJK Compat. Idgphs. */
/* TODO: there's also the U+20000 and U+2f800 planes, but they're
* not supported by the Twitter Javascript filter (yet?). */
/* Stupid symbols and Dingbats shit */
#define RANGE_SYMBOLS 0x25a0, 0x2600, /* Geometric Shapes */ \
0x2600, 0x269e, 0x26a0, 0x26bd, 0x26c0, 0x26c4, /* Misc. Symbols */ \
0x2701, 0x2705, 0x2706, 0x270a, 0x270c, 0x2728, 0x2729, 0x274c, \
0x274d, 0x274e, 0x274f, 0x2753, 0x2756, 0x2757, 0x2758, 0x275f, \
0x2761, 0x2795, 0x2798, 0x27b0, 0x27b1, 0x27bf /* Dingbats */
/* End of list marker */
#define RANGE_END 0x0, 0x0
/* Pre-defined character ranges XXX: must be _ordered_ */
static const uint32_t unichars_ascii[] = { RANGE_ASCII, RANGE_END };
static const uint32_t unichars_cjk[] = { RANGE_CJK, RANGE_END };
static const uint32_t unichars_symbols[] = { RANGE_SYMBOLS, RANGE_END };
/* The Unicode characters at disposal */
static const uint32_t *unichars;
/* The maximum image size we want to support, and the version range */
#define RANGE_W 2000
#define RANGE_H 2000
#define RANGE_V 10
/* Start with a random image (1), or with a good estimate (0)? */
#define RANDOM_START 0
/*
* These values can be overwritten at runtime
*/
/* Debug mode */
static bool DEBUG_MODE = false;
/* The maximum message length */
static int MAX_MSG_LEN = 140;
/* Iterations per point -- larger means slower but nicer */
static int ITERATIONS_PER_POINT = 50;
/* Points per cell -- 1 allows to put more cells, but 2 gives better results */
static int POINTS_PER_CELL = 2;
/* The range value for point parameters: X Y, red/green/blue, "strength"
* Tested values (on Mona Lisa) are:
* 16 16 5 5 5 2 -> 0.06511725914
* 16 16 6 7 6 1 -> 0.05731491348 *
* 16 16 7 6 6 1 -> 0.06450513783
* 14 14 7 7 6 1 -> 0.0637207893
* 19 19 6 6 5 1 -> 0.06801999094 */
static unsigned int RANGE_X = 16;
static unsigned int RANGE_Y = 16;
static unsigned int RANGE_R = 6;
static unsigned int RANGE_G = 6;
static unsigned int RANGE_B = 6;
static unsigned int RANGE_S = 1;
/*
* These values are computed at runtime
*/
static float TOTAL_BITS;
static float HEADER_BITS;
static float DATA_BITS;
static float CELL_BITS;
static int NUM_CHARACTERS;
static int MAX_ITERATIONS;
static unsigned int TOTAL_CELLS;
#define RANGE_XY2 (RANGE_Y*RANGE_X*(RANGE_Y*RANGE_X+1)/2)
#define RANGE_SBGR (RANGE_R*RANGE_G*RANGE_B*RANGE_S)
#define RANGE_SBGRXY (RANGE_Y*RANGE_X*RANGE_R*RANGE_G*RANGE_B*RANGE_S)
struct K : CGAL::Exact_predicates_inexact_constructions_kernel {};
typedef CGAL::Delaunay_triangulation_2<K> Delaunay_triangulation;
typedef std::vector<std::pair<K::Point_2, K::FT> > Point_coordinate_vector;
/* Global aspect ratio */
static unsigned int dw, dh;
/* Algorithm version */
static unsigned int version;
/* Global point encoding */
typedef struct point
{
uint8_t x, y, r, g, b, s;
}
point_t;
static point_t points[4096]; /* FIXME: allocate this dynamically */
static int npoints = 0;
/* Global triangulation */
static Delaunay_triangulation dt;
/*
* Bit allocation handling
*/
void compute_ranges(int width, int height)
{
TOTAL_BITS = MAX_MSG_LEN * logf(NUM_CHARACTERS) / logf(2);
HEADER_BITS = logf(RANGE_W * RANGE_H * RANGE_V) / logf(2);
DATA_BITS = TOTAL_BITS - HEADER_BITS;
if(version == 0)
{
POINTS_PER_CELL = 1;
CELL_BITS = logf(RANGE_SBGRXY) / logf(2);
}
else if(version == 1)
{
POINTS_PER_CELL = 2;
CELL_BITS = (2 * logf(RANGE_SBGR) + logf(RANGE_XY2)) / logf(2);
}
TOTAL_CELLS = (int)(DATA_BITS / CELL_BITS);
MAX_ITERATIONS = ITERATIONS_PER_POINT * POINTS_PER_CELL * TOTAL_CELLS;
/* Compute "best" w/h ratio */
dw = 1; dh = TOTAL_CELLS;
for(unsigned int i = 1; i <= TOTAL_CELLS; i++)
{
int j = TOTAL_CELLS / i;
float r = (float)width / (float)height;
float ir = (float)i / (float)j;
float dwr = (float)dw / (float)dh;
if(fabs(logf(r / ir)) < fabs(logf(r / dwr)))
{
dw = i;
dh = TOTAL_CELLS / dw;
}
}
while((dh + 1) * dw <= TOTAL_CELLS) dh++;
while(dh * (dw + 1) <= TOTAL_CELLS) dw++;
}
/*
* Unicode stuff handling
*/
/* Return the number of chars in the unichars table */
static int count_unichars(void)
{
int ret = 0;
for(int u = 0; unichars[u] != unichars[u + 1]; u += 2)
ret += unichars[u + 1] - unichars[u];
return ret;
}
/* Get the ith Unicode character in our list */
static uint32_t index2uni(uint32_t i)
{
for(int u = 0; unichars[u] != unichars[u + 1]; u += 2)
if(i < unichars[u + 1] - unichars[u])
return unichars[u] + i;
else
i -= unichars[u + 1] - unichars[u];
return 0; /* Should not happen! */
}
/* Convert a Unicode character to its position in the compact list */
static uint32_t uni2index(uint32_t x)
{
uint32_t ret = 0;
for(int u = 0; unichars[u] != unichars[u + 1]; u += 2)
if(x < unichars[u + 1])
return ret + x - unichars[u];
else
ret += unichars[u + 1] - unichars[u];
return ret; /* Should not happen! */
}
static uint8_t const utf8_trailing[256] =
{
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5
};
static uint32_t const utf8_offsets[6] =
{
0x00000000UL, 0x00003080UL, 0x000E2080UL,
0x03C82080UL, 0xFA082080UL, 0x82082080UL
};
static uint32_t fread_utf8(FILE *f)
{
int ch, i = 0, todo = -1;
uint32_t ret = 0;
for(;;)
{
ch = fgetc(f);
if(!ch)
return 0;
if(todo == -1)
todo = utf8_trailing[ch];
ret += ((uint32_t)ch) << (6 * (todo - i));
if(todo == i++)
return ret - utf8_offsets[todo];
}
}
static void fwrite_utf8(FILE *f, uint32_t x)
{
static const uint8_t mark[7] =
{
0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC
};
char buf[8];
char *parser = buf;
size_t bytes;
if(x < 0x80)
{
fprintf(f, "%c", x);
return;
}
bytes = (x < 0x800) ? 2 : (x < 0x10000) ? 3 : 4;
parser += bytes;
*parser = '\0';
switch(bytes)
{
case 4: *--parser = (x | 0x80) & 0xbf; x >>= 6;
case 3: *--parser = (x | 0x80) & 0xbf; x >>= 6;
case 2: *--parser = (x | 0x80) & 0xbf; x >>= 6;
}
*--parser = x | mark[bytes];
fprintf(f, "%s", buf);
}
/*
* Our nifty non-power-of-two bitstack handling
*/
class bitstack
{
public:
bitstack(int max) { alloc(max); init(0); }
~bitstack() { delete[] digits; delete[] str; }
char const *tostring()
{
int pos = sprintf(str, "0x%x", digits[msb]);
for(int i = msb - 1; i >= 0; i--)
pos += sprintf(str + pos, "%08x", digits[i]);
return str;
}
void push(uint32_t val, uint32_t range)
{
if(!range)
return;
mul(range);
add(val % range);
}
uint32_t pop(uint32_t range)
{
if(!range)
return 0;
return div(range);
}
bool isempty()
{
for(int i = msb; i >= 0; i--)
if(digits[i])
return false;
return true;
}
private:
bitstack(int max, uint32_t x) { alloc(max); init(x); }
bitstack(bitstack &b)
{
alloc(b.max_size);
msb = b.msb;
memcpy(digits, b.digits, (max_size + 1) * sizeof(uint32_t));
}
bitstack(bitstack const &b)
{
alloc(b.max_size);
msb = b.msb;
memcpy(digits, b.digits, (max_size + 1) * sizeof(uint32_t));
}
void alloc(int max)
{
max_size = max;
digits = new uint32_t[max_size + 1];
str = new char[(max_size + 1) * 8 + 1];
}
void init(uint32_t i)
{
msb = 0;
memset(digits, 0, (max_size + 1) * sizeof(uint32_t));
digits[0] = i;
}
/* Could be done much faster, but we don't care! */
void add(uint32_t x) { add(bitstack(max_size, x)); }
void sub(uint32_t x) { sub(bitstack(max_size, x)); }
void add(bitstack const &_b)
{
/* Copy the operand in case we get added to ourselves */
bitstack b(_b);
uint64_t x = 0;
if(msb < b.msb)
msb = b.msb;
for(int i = 0; i <= msb; i++)
{
uint64_t tmp = (uint64_t)digits[i] + (uint64_t)b.digits[i] + x;
digits[i] = tmp;
if((uint64_t)digits[i] == tmp)
x = 0;
else
{
x = 1;
if(i == msb)
msb++;
}
}
}
void sub(bitstack const &_b)
{
/* Copy the operand in case we get substracted from ourselves */
bitstack b(_b);
uint64_t x = 0;
/* We cannot substract a larger number! */
if(msb < b.msb)
{
init(0);
return;
}
for(int i = 0; i <= msb; i++)
{
uint64_t tmp = (uint64_t)digits[i] - (uint64_t)b.digits[i] - x;
digits[i] = tmp;
if((uint64_t)digits[i] == tmp)
x = 0;
else
{
x = 1;
if(i == msb)
{
/* Error: carry into MSB! */
init(0);
return;
}
}
}
while(msb > 0 && digits[msb] == 0) msb--;
}
void mul(uint32_t x)
{
bitstack b(*this);
init(0);
while(x)
{
if(x & 1)
add(b);
x /= 2;
b.add(b);
}
}
uint32_t div(uint32_t x)
{
bitstack b(*this);
for(int i = msb; i >= 0; i--)
{
uint64_t tmp = b.digits[i] + (((uint64_t)b.digits[i + 1]) << 32);
uint32_t res = tmp / x;
uint32_t rem = tmp % x;
digits[i]= res;
b.digits[i + 1] = 0;
b.digits[i] = rem;
}
while(msb > 0 && digits[msb] == 0) msb--;
return b.digits[0];
}
int msb, max_size;
uint32_t *digits;
char *str;
};
/*
* Point handling
*/
static unsigned int det_rand(unsigned int mod)
{
static unsigned long next = 1;
next = next * 1103515245 + 12345;
return ((unsigned)(next / 65536) % 32768) % mod;
}
static inline int range2int(float val, int range)
{
int ret = (int)(val * ((float)range - 0.0001));
return ret < 0 ? 0 : ret > range - 1 ? range - 1 : ret;
}
static inline float int2midrange(int val, int range)
{
return (float)(1 + 2 * val) / (float)(2 * range);
}
static inline float int2fullrange(int val, int range)
{
return range > 1 ? (float)val / (float)(range - 1) : 0.0;
}
static inline void index2cell(int index, int *dx, int *dy)
{
*dx = (index / POINTS_PER_CELL) % dw;
*dy = (index / POINTS_PER_CELL) / dw;
}
static inline void set_point(int index, float x, float y, float r,
float g, float b, float s)
{
int dx, dy;
index2cell(index, &dx, &dy);
float fx = (x - dx * RANGE_X) / RANGE_X;
float fy = (y - dy * RANGE_Y) / RANGE_Y;
points[index].x = range2int(fx, RANGE_X);
points[index].y = range2int(fy, RANGE_Y);
points[index].r = range2int(r, RANGE_R);
points[index].g = range2int(g, RANGE_G);
points[index].b = range2int(b, RANGE_B);
points[index].s = range2int(s, RANGE_S);
}
static inline void get_point(int index, float *x, float *y, float *r,
float *g, float *b, float *s)
{
int dx, dy;
index2cell(index, &dx, &dy);
float fx = int2midrange(points[index].x, RANGE_X);
float fy = int2midrange(points[index].y, RANGE_Y);
*y = (fy + dy) * RANGE_Y /*+ 0.5 * (index & 1)*/;
*x = (fx + dx) * RANGE_X /*+ 0.5 * (index & 1)*/;
*r = int2fullrange(points[index].r, RANGE_R);
*g = int2fullrange(points[index].g, RANGE_G);
*b = int2fullrange(points[index].b, RANGE_B);
*s = int2fullrange(points[index].s, RANGE_S);
}
static void add_point(float x, float y, float r, float g, float b, float s)
{
set_point(npoints, x, y, r, g, b, s);
npoints++;
}
static uint32_t pack_coords(int x1, int y1, int x2, int y2, bool *swap)
{
int k1 = y1 * RANGE_X + x1;
int k2 = y2 * RANGE_X + x2;
/* XXX: this should not happen */
if(k1 == k2)
k1 += (x1 > 0 ? -1 : 1);
*swap = k1 > k2;
if(*swap)
{
int tmp = k1; k1 = k2; k2 = tmp;
}
return k2 * (k2 + 1) / 2 + k1;
}
static void unpack_coords(uint32_t pack, int *x1, int *y1, int *x2, int *y2)
{
int k2 = ((int)sqrt(1.0 + 8 * pack) - 1) / 2;
int k1 = pack - k2 * (k2 + 1) / 2;
*x1 = k1 % RANGE_X;
*y1 = k1 / RANGE_X;
*x2 = k2 % RANGE_X;
*y2 = k2 / RANGE_X;
}
#if RANDOM_START == 1
static void add_random_point()
{
points[npoints].x = det_rand(RANGE_X);
points[npoints].y = det_rand(RANGE_Y);
points[npoints].r = det_rand(RANGE_R);
points[npoints].g = det_rand(RANGE_G);
points[npoints].b = det_rand(RANGE_B);
points[npoints].s = det_rand(RANGE_S);
npoints++;
}
#endif
#define NB_OPS 20
static uint8_t rand_op(void)
{
uint8_t x = det_rand(NB_OPS);
/* Randomly ignore statistically less efficient ops */
if(x == 0)
return rand_op();
if(x == 1 && (RANGE_S == 1 || det_rand(2)))
return rand_op();
if(x <= 5 && det_rand(2))
return rand_op();
//if((x < 10 || x > 15) && !det_rand(4)) /* Favour colour changes */
// return rand_op();
return x;
}
static void apply_op(uint8_t op, point_t *val)
{
switch(op)
{
case 0: /* Flip strength value */
case 1:
/* Statistics show that this helps often, but does not reduce
* the error significantly. */
val->s ^= 1; break;
case 2: /* Move up; if impossible, down */
val->y = val->y > 0 ? val->y - 1 : val->y + 1; break;
case 3: /* Move down; if impossible, up */
val->y = val->y + 1U < RANGE_Y ? val->y + 1 : val->y - 1; break;
case 4: /* Move left; if impossible, right */
val->x = val->x > 0 ? val->x - 1 : val->x + 1; break;
case 5: /* Move right; if impossible, left */
val->x = val->x + 1U < RANGE_X ? val->x + 1 : val->x - 1; break;
case 6: /* Corner 1 */
val->y = val->y > 0 ? val->y - 1 : val->y + 1;
val->x = val->x > 0 ? val->x - 1 : val->x + 1; break;
case 7: /* Corner 2 */
val->y = val->y > 0 ? val->y - 1 : val->y + 1;
val->x = val->x + 1U < RANGE_X ? val->x + 1 : val->x - 1; break;
case 8: /* Corner 3 */
val->y = val->y + 1U < RANGE_Y ? val->y + 1 : val->y - 1;
val->x = val->x + 1U < RANGE_X ? val->x + 1 : val->x - 1; break;
case 9: /* Corner 4 */
val->y = val->y + 1U < RANGE_Y ? val->y + 1 : val->y - 1;
val->x = val->x > 0 ? val->x - 1 : val->x + 1; break;
case 16: /* Double up */
val->y = val->y > 1 ? val->y - 2 : val->y + 2; break;
case 17: /* Double down */
val->y = val->y + 2U < RANGE_Y ? val->y + 2 : val->y - 2; break;
case 18: /* Double left */
val->x = val->x > 1 ? val->x - 2 : val->x + 2; break;
case 19: /* Double right */
val->x = val->x + 2U < RANGE_X ? val->x + 2 : val->x - 2; break;
case 10: /* R-- (or R++) */
val->r = val->r > 0 ? val->r - 1 : val->r + 1; break;
case 11: /* R++ (or R--) */
val->r = val->r + 1U < RANGE_R ? val->r + 1 : val->r - 1; break;
case 12: /* G-- (or G++) */
val->g = val->g > 0 ? val->g - 1 : val->g + 1; break;
case 13: /* G++ (or G--) */
val->g = val->g + 1U < RANGE_G ? val->g + 1 : val->g - 1; break;
case 14: /* B-- (or B++) */
val->b = val->b > 0 ? val->g - 1 : val->b + 1; break;
case 15: /* B++ (or B--) */
val->b = val->b + 1U < RANGE_B ? val->b + 1 : val->b - 1; break;
#if 0
case 15: /* Brightness-- */
apply_op(9, val); apply_op(11, val); apply_op(13, val); break;
case 16: /* Brightness++ */
apply_op(10, val); apply_op(12, val); apply_op(14, val); break;
case 17: /* RG-- */
apply_op(9, val); apply_op(11, val); break;
case 18: /* RG++ */
apply_op(10, val); apply_op(12, val); break;
case 19: /* GB-- */
apply_op(11, val); apply_op(13, val); break;
case 20: /* GB++ */
apply_op(12, val); apply_op(14, val); break;
case 21: /* RB-- */
apply_op(9, val); apply_op(13, val); break;
case 22: /* RB++ */
apply_op(10, val); apply_op(14, val); break;
#endif
default:
break;
}
}
static void render(pipi_image_t *dst, int rx, int ry, int rw, int rh)
{
int lookup[dw * RANGE_X * 2 * dh * RANGE_Y * 2];
pipi_pixels_t *p = pipi_get_pixels(dst, PIPI_PIXELS_RGBA_F32);
float *data = (float *)p->pixels;
int x, y;
memset(lookup, 0, sizeof(lookup));
dt.clear();
for(int i = 0; i < npoints; i++)
{
float fx, fy, fr, fg, fb, fs;
get_point(i, &fx, &fy, &fr, &fg, &fb, &fs);
dt.insert(K::Point_2(fx + dw * RANGE_X, fy + dh * RANGE_Y));
/* Keep link to point */
lookup[(int)(fx * 2) + dw * RANGE_X * 2 * (int)(fy * 2)] = i;
}
/* Add fake points to close the triangulation */
dt.insert(K::Point_2(0, 0));
dt.insert(K::Point_2(3 * dw * RANGE_X, 0));
dt.insert(K::Point_2(0, 3 * dh * RANGE_Y));
dt.insert(K::Point_2(3 * dw * RANGE_X, 3 * dh * RANGE_Y));
for(y = ry; y < ry + rh; y++)
{
for(x = rx; x < rx + rw; x++)
{
float myx = (float)x * dw * RANGE_X / p->w;
float myy = (float)y * dh * RANGE_Y / p->h;
K::Point_2 m(myx + dw * RANGE_X, myy + dh * RANGE_Y);
Point_coordinate_vector coords;
CGAL::Triple<
std::back_insert_iterator<Point_coordinate_vector>,
K::FT, bool> result =
CGAL::natural_neighbor_coordinates_2(dt, m,
std::back_inserter(coords));
float r = 0.0f, g = 0.0f, b = 0.0f, norm = 0.000000000000001f;
Point_coordinate_vector::iterator it;
for(it = coords.begin(); it != coords.end(); ++it)
{
float fx, fy, fr, fg, fb, fs;
fx = (*it).first.x() - dw * RANGE_X;
fy = (*it).first.y() - dh * RANGE_Y;
if(fx < 0 || fy < 0
|| fx > dw * RANGE_X - 1 || fy > dh * RANGE_Y - 1)
continue;
int index = lookup[(int)(fx * 2)
+ dw * RANGE_X * 2 * (int)(fy * 2)];
get_point(index, &fx, &fy, &fr, &fg, &fb, &fs);
//float k = pow((*it).second * (1.0 + fs), 1.2);
float k = (*it).second * (1.00f + fs);
//float k = (*it).second * (0.60f + fs);
//float k = pow((*it).second, (1.0f + fs));
// Try to attenuate peak artifacts
k *= pow(((myx - fx) * (myx - fx) + (myy - fy) * (myy - fy)
+ 0.01) / (RANGE_X * RANGE_X + RANGE_Y * RANGE_Y),
-0.5);
// Cute circles
//k = 1.0 / (0.015 * (RANGE_X * RANGE_X + RANGE_Y * RANGE_Y)
// + (myx - fx) * (myx - fx) + (myy - fy) * (myy - fy));
r += k * fr;
g += k * fg;
b += k * fb;
norm += k;
}
data[4 * (x + y * p->w) + 0] = r / norm;
data[4 * (x + y * p->w) + 1] = g / norm;
data[4 * (x + y * p->w) + 2] = b / norm;
data[4 * (x + y * p->w) + 3] = 0.0;
}
}
pipi_release_pixels(dst, p);
}
static void analyse(pipi_image_t *src)
{
pipi_pixels_t *p = pipi_get_pixels(src, PIPI_PIXELS_RGBA_F32);
float *data = (float *)p->pixels;
for(unsigned int dy = 0; dy < dh; dy++)
for(unsigned int dx = 0; dx < dw; dx++)
{
float min = 1.1f, max = -0.1f, mr = 0.0f, mg = 0.0f, mb = 0.0f;
float total = 0.0;
int xmin = 0, xmax = 0, ymin = 0, ymax = 0;
int npixels = 0;
for(unsigned int iy = RANGE_Y * dy; iy < RANGE_Y * (dy + 1); iy++)
for(unsigned int ix = RANGE_X * dx; ix < RANGE_X * (dx + 1); ix++)
{
float lum = 0.0f;
lum += data[4 * (ix + iy * p->w) + 0];
lum += data[4 * (ix + iy * p->w) + 1];
lum += data[4 * (ix + iy * p->w) + 2];
lum /= 3;
mr += data[4 * (ix + iy * p->w) + 0];
mg += data[4 * (ix + iy * p->w) + 1];
mb += data[4 * (ix + iy * p->w) + 2];
if(lum < min)
{
min = lum;
xmin = ix;
ymin = iy;
}
if(lum > max)
{
max = lum;
xmax = ix;
ymax = iy;
}
total += lum;
npixels++;
}
total /= npixels;
mr /= npixels;
mg /= npixels;
mb /= npixels;
float wmin, wmax;
if(total < min + (max - min) / 4)
wmin = 1.0, wmax = 0.0;
else if(total < min + (max - min) / 4 * 3)
wmin = 0.0, wmax = 0.0;
else
wmin = 0.0, wmax = 1.0;
#if RANDOM_START == 1
for(int i = 0; i < POINTS_PER_CELL; i++)
add_random_point();
#else
/* 0.80 and 0.20 were chosen empirically, it gives a 10% better
* initial distance. Definitely worth it. */
if(POINTS_PER_CELL == 2 || total < min + (max - min) / 2)
add_point(xmin, ymin,
data[4 * (xmin + ymin * p->w) + 0] * 0.80 + mr * 0.20,
data[4 * (xmin + ymin * p->w) + 1] * 0.80 + mg * 0.20,
data[4 * (xmin + ymin * p->w) + 2] * 0.80 + mb * 0.20,
wmin);
if(POINTS_PER_CELL == 2 || total >= min + (max - min) / 2)
add_point(xmax, ymax,
data[4 * (xmax + ymax * p->w) + 0] * 0.80 + mr * 0.20,
data[4 * (xmax + ymax * p->w) + 1] * 0.80 + mg * 0.20,
data[4 * (xmax + ymax * p->w) + 2] * 0.80 + mb * 0.20,
wmax);
#endif
}
}
#define MOREINFO "Try `%s --help' for more information.\n"
int main(int argc, char *argv[])
{
uint32_t unicode_data[2048];
int opstats[2 * NB_OPS];
char const *srcname = NULL, *dstname = NULL;
pipi_image_t *src, *tmp, *dst;
double error = 1.0;
int width, height;
/* Parse command-line options */
for(;;)
{
int option_index = 0;
static struct myoption long_options[] =
{
{ "output", 1, NULL, 'o' },
{ "length", 1, NULL, 'l' },
{ "charset", 1, NULL, 'c' },
{ "quality", 1, NULL, 'q' },
{ "debug", 0, NULL, 'd' },
{ "help", 0, NULL, 'h' },
{ NULL, 0, NULL, 0 },
};
int c = mygetopt(argc, argv, "o:l:c:q:dh", long_options, &option_index);
if(c == -1)
break;
switch(c)
{
case 'o':
dstname = myoptarg;
break;
case 'l':
MAX_MSG_LEN = atoi(myoptarg);
if(MAX_MSG_LEN < 16)
{
fprintf(stderr, "Warning: rounding minimum message length to 16\n");
MAX_MSG_LEN = 16;
}
break;
case 'c':
if(!strcmp(myoptarg, "ascii"))
unichars = unichars_ascii;
else if(!strcmp(myoptarg, "cjk"))
unichars = unichars_cjk;
else if(!strcmp(myoptarg, "symbols"))
unichars = unichars_symbols;
else
{
fprintf(stderr, "Error: invalid char block \"%s\".", myoptarg);
fprintf(stderr, "Valid sets are: ascii, cjk, symbols\n");
return EXIT_FAILURE;
}
break;
case 'q':
ITERATIONS_PER_POINT = 10 * atof(myoptarg);
if(ITERATIONS_PER_POINT < 0)
ITERATIONS_PER_POINT = 0;
else if(ITERATIONS_PER_POINT > 200)
ITERATIONS_PER_POINT = 200;
break;
case 'd':
DEBUG_MODE = true;
break;
case 'h':
printf("Usage: img2twit [OPTIONS] SOURCE\n");
printf(" img2twit [OPTIONS] -o DESTINATION\n");
printf("Encode SOURCE image to stdout or decode stdin to DESTINATION.\n");
printf("\n");
printf("Mandatory arguments to long options are mandatory for short options too.\n");
printf(" -o, --output <filename> output resulting image to filename\n");
printf(" -l, --length <size> message length in characters (default 140)\n");
printf(" -c, --charset <block> character set to use (ascii, [cjk], symbols)\n");
printf(" -q, --quality <rate> set image quality (0 - 20) (default 5)\n");
printf(" -d, --debug print debug information\n");
printf(" -h, --help display this help and exit\n");
printf("\n");
printf("Written by Sam Hocevar. Report bugs to <sam@hocevar.net>.\n");
return EXIT_SUCCESS;
default:
fprintf(stderr, "%s: invalid option -- %c\n", argv[0], c);
printf(MOREINFO, argv[0]);
return EXIT_FAILURE;
}
}
if(myoptind == argc && !dstname)
{
fprintf(stderr, "%s: too few arguments\n", argv[0]);
printf(MOREINFO, argv[0]);
return EXIT_FAILURE;
}
if((myoptind == argc - 1 && dstname) || myoptind < argc - 1)
{
fprintf(stderr, "%s: too many arguments\n", argv[0]);
printf(MOREINFO, argv[0]);
return EXIT_FAILURE;
}
if(myoptind == argc - 1)
srcname = argv[myoptind];
/* Decoding mode: read UTF-8 text from stdin */
if(dstname)
for(MAX_MSG_LEN = 0; ;)
{
uint32_t ch = fread_utf8(stdin);
if(ch == 0xffffffff || ch == '\n')
break;
if(ch <= ' ')
continue;
unicode_data[MAX_MSG_LEN++] = ch;
if(MAX_MSG_LEN >= 2048)
{
fprintf(stderr, "Error: message too long.\n");
return EXIT_FAILURE;
}
}
if(MAX_MSG_LEN == 0)
{
fprintf(stderr, "Error: empty message.\n");
return EXIT_FAILURE;
}
bitstack b(MAX_MSG_LEN); /* We cannot declare this before, because
* MAX_MSG_LEN wouldn't be defined. */
/* Autodetect charset if decoding, otherwise switch to CJK. */
if(dstname)
{
char const *charset;
if(unicode_data[0] >= 0x0021 && unicode_data[0] < 0x007f)
{
unichars = unichars_ascii;
charset = "ascii";
}
else if(unicode_data[0] >= 0x4e00 && unicode_data[0] < 0x9fa6)
{
unichars = unichars_cjk;
charset = "cjk";
}
else if(unicode_data[0] >= 0x25a0 && unicode_data[0] < 0x27bf)
{
unichars = unichars_symbols;
charset = "symbols";
}
else
{
fprintf(stderr, "Error: unable to detect charset\n");
return EXIT_FAILURE;
}
if(DEBUG_MODE)
fprintf(stderr, "Detected charset \"%s\"\n", charset);
}
else if(!unichars)
unichars = unichars_cjk;
pipi_set_gamma(1.0);
/* Precompute bit allocation */
NUM_CHARACTERS = count_unichars();
if(dstname)
{
/* Decoding mode: find each character's index in our character
* list, and push it to our wonderful custom bitstream. */
for(int i = MAX_MSG_LEN; i--; )
b.push(uni2index(unicode_data[i]), NUM_CHARACTERS);
/* The first thing we pop from the stream is the version information */
version = b.pop(RANGE_V);
if(version > 1)
{
fprintf(stderr, "Error: unsupported algorithm version %i\n",
version);
return EXIT_FAILURE;
}
/* Read width and height from bitstream */
width = b.pop(RANGE_W) + 1;
height = b.pop(RANGE_H) + 1;
src = NULL;
}
else
{
/* Argument given: open image for encoding */
src = pipi_load(srcname);
if(!src)
{
fprintf(stderr, "Error loading %s\n", srcname);
return EXIT_FAILURE;
}
version = 1;
width = pipi_get_image_width(src);
height = pipi_get_image_height(src);
}
if(width <= 0 || height <= 0 || width > RANGE_W || height > RANGE_H)
{
fprintf(stderr, "Error: image size %ix%i is out of bounds\n",
width, height);
return EXIT_FAILURE;
}
compute_ranges(width, height);
/* Try to cram some more information into our points as long as it
* does not change the cell distribution. This cannot be too clever,
* because we want the computation to depend only on the source image
* coordinates. */
#define TRY(op, revert) \
do { \
unsigned int olddw = dw, olddh = dh; \
op; compute_ranges(width, height); \
if(dw != olddw || dh != olddh) \
{ revert; compute_ranges(width, height); } \
} while(0)
for(int i = 0; i < 2; i++)
{
TRY(RANGE_G++, RANGE_G--);
TRY(RANGE_R++, RANGE_R--);
TRY(RANGE_B++, RANGE_B--);
}
for(int i = 0; i < 10; i++)
{
if((float)width / dw >= (float)height / dh)
{
TRY(RANGE_X++, RANGE_X--);
TRY(RANGE_Y++, RANGE_Y--);
}
else
{
TRY(RANGE_Y++, RANGE_Y--);
TRY(RANGE_X++, RANGE_X--);
}
}
/* Print debug information */
if(DEBUG_MODE)
{
fprintf(stderr, "Message size: %i\n", MAX_MSG_LEN);
fprintf(stderr, "Available characters: %i\n", NUM_CHARACTERS);
fprintf(stderr, "Available bits: %f\n", TOTAL_BITS);
fprintf(stderr, "Width/Height ranges: %ix%i\n", RANGE_W, RANGE_H);
fprintf(stderr, "Algorithm version: %i\n", RANGE_V);
fprintf(stderr, "Image resolution: %ix%i\n", width, height);
fprintf(stderr, "Header bits: %f\n", HEADER_BITS);
fprintf(stderr, "Bits available for data: %f\n", DATA_BITS);
fprintf(stderr, "X/Y/Red/Green/Blue/Extra ranges: %i %i %i %i %i %i\n",
RANGE_X, RANGE_Y, RANGE_R, RANGE_G, RANGE_B, RANGE_S);
fprintf(stderr, "Cell bits: %f\n", CELL_BITS);
fprintf(stderr, "Available cells: %i\n", TOTAL_CELLS);
fprintf(stderr, "Wasted bits: %f\n",
DATA_BITS - CELL_BITS * TOTAL_CELLS);
fprintf(stderr, "Chosen image ratio: %i:%i (wasting %i point cells)\n",
dw, dh, TOTAL_CELLS - dw * dh);
fprintf(stderr, "Total wasted bits: %f\n",
DATA_BITS - CELL_BITS * dw * dh);
}
if(srcname)
{
/* Resize and filter image to better state */
tmp = pipi_gaussian_blur(src, 0.25 * dw * RANGE_X / width);
pipi_free(src);
src = pipi_resize(tmp, dw * RANGE_X, dh * RANGE_Y);
pipi_free(tmp);
/* Analyse image */
analyse(src);
/* Render what we just computed */
tmp = pipi_new(dw * RANGE_X, dh * RANGE_Y);
render(tmp, 0, 0, dw * RANGE_X, dh * RANGE_Y);
error = pipi_measure_rmsd(src, tmp);
if(DEBUG_MODE)
fprintf(stderr, "Initial distance: %2.10g\n", error);
memset(opstats, 0, sizeof(opstats));
for(int iter = 0, stuck = 0, failures = 0, success = 0;
iter < MAX_ITERATIONS /* && stuck < 5 && */;
iter++)
{
if(failures > 500)
{
stuck++;
failures = 0;
}
if(!DEBUG_MODE && !(iter % 16))
fprintf(stderr, "\rEncoding... %i%%",
iter * 100 / MAX_ITERATIONS);
pipi_image_t *scrap = pipi_copy(tmp);
/* Choose a point at random */
int pt = det_rand(npoints);
point_t oldpt = points[pt];
/* Compute the affected image zone */
float fx, fy, fr, fg, fb, fs;
get_point(pt, &fx, &fy, &fr, &fg, &fb, &fs);
int zonex = (int)fx / RANGE_X - 2;
int zoney = (int)fy / RANGE_Y - 2;
int zonew = 4;
int zoneh = 4;
if(zonex < 0) { zonew += zonex; zonex = 0; }
if(zoney < 0) { zoneh += zoney; zoney = 0;; }
if(zonex + zonew > (int)dw) { zonew = dw - zonex; }
if(zoney + zoneh > (int)dh) { zoneh = dh - zoney; }
/* Choose random operations and measure their effect */
uint8_t op1 = rand_op();
//uint8_t op2 = rand_op();
apply_op(op1, &points[pt]);
/* Check that two points don't fall at the same place */
if(POINTS_PER_CELL == 2)
{
while(points[pt].x == points[pt ^ 1].x
&& points[pt].y == points[pt ^ 1].y)
{
points[pt] = oldpt;
op1 = rand_op();
apply_op(op1, &points[pt]);
}
}
render(scrap, zonex * RANGE_X, zoney * RANGE_Y,
zonew * RANGE_X, zoneh * RANGE_Y);
double newerr = pipi_measure_rmsd(src, scrap);
opstats[op1 * 2]++;
//opstats[op2 * 2]++;
if(newerr < error)
{
pipi_free(tmp);
#if 0
/* Save image! */
if((success % 10) == 0)
{
char buf[128];
sprintf(buf, "twit%08i.bmp", success);
tmp = pipi_new(width, height);
render(tmp, 0, 0, width, height);
pipi_save(tmp, buf);
pipi_free(tmp);
}
#endif
tmp = scrap;
if(DEBUG_MODE)
fprintf(stderr, "%08i -0.%010i %2.010g after op%i(%i)\n",
iter, (int)((error - newerr) * 10000000000L),
error, op1, pt);
error = newerr;
opstats[op1 * 2 + 1]++;
//opstats[op2 * 2 + 1]++;
failures = 0;
success++;
}
else
{
pipi_free(scrap);
points[pt] = oldpt;
failures++;
}
}
if(DEBUG_MODE)
{
for(int j = 0; j < 2; j++)
{
fprintf(stderr, "operation: ");
for(int i = NB_OPS / 2 * j; i < NB_OPS / 2 * (j + 1); i++)
fprintf(stderr, "%4i ", i);
fprintf(stderr, "\nattempts: ");
for(int i = NB_OPS / 2 * j; i < NB_OPS / 2 * (j + 1); i++)
fprintf(stderr, "%4i ", opstats[i * 2]);
fprintf(stderr, "\nsuccesses: ");
for(int i = NB_OPS / 2 * j; i < NB_OPS / 2 * (j + 1); i++)
fprintf(stderr, "%4i ", opstats[i * 2 + 1]);
fprintf(stderr, "\n");
}
fprintf(stderr, "Distance: %2.10g\n", error);
}
else
fprintf(stderr, "\r \r");
#if 0
dst = pipi_resize(tmp, width, height);
pipi_free(tmp);
/* Save image and bail out */
pipi_save(dst, "lol.bmp");
pipi_free(dst);
#endif
/* Push our points to the bitstream */
for(int i = 0; i < npoints; i += POINTS_PER_CELL)
{
if(POINTS_PER_CELL == 2)
{
int x1, y1, x2, y2;
x1 = points[i].x;
y1 = points[i].y;
x2 = points[i + 1].x;
y2 = points[i + 1].y;
bool swap;
uint32_t pack = pack_coords(x1, y1, x2, y2, &swap);
b.push(points[i + (swap ? 1 : 0)].s, RANGE_S);
b.push(points[i + (swap ? 1 : 0)].b, RANGE_B);
b.push(points[i + (swap ? 1 : 0)].g, RANGE_G);
b.push(points[i + (swap ? 1 : 0)].r, RANGE_R);
b.push(points[i + (swap ? 0 : 1)].s, RANGE_S);
b.push(points[i + (swap ? 0 : 1)].b, RANGE_B);
b.push(points[i + (swap ? 0 : 1)].g, RANGE_G);
b.push(points[i + (swap ? 0 : 1)].r, RANGE_R);
b.push(pack, RANGE_XY2);
}
else
{
b.push(points[i].s, RANGE_S);
b.push(points[i].b, RANGE_B);
b.push(points[i].g, RANGE_G);
b.push(points[i].r, RANGE_R);
b.push(points[i].x, RANGE_X);
b.push(points[i].y, RANGE_Y);
}
}
b.push(height - 1, RANGE_H);
b.push(width - 1, RANGE_W);
b.push(version, RANGE_V);
/* Pop Unicode characters from the bitstream and print them */
for(int i = 0; i < MAX_MSG_LEN; i++)
fwrite_utf8(stdout, index2uni(b.pop(NUM_CHARACTERS)));
fprintf(stdout, "\n");
}
else
{
/* Pop points from the bitstream */
for(int i = dw * dh; i--; )
{
if(POINTS_PER_CELL == 2)
{
uint32_t pack = b.pop(RANGE_XY2);
int x1, y1, x2, y2;
unpack_coords(pack, &x1, &y1, &x2, &y2);
points[i * 2 + 1].y = y2;
points[i * 2 + 1].x = x2;
points[i * 2 + 1].r = b.pop(RANGE_R);
points[i * 2 + 1].g = b.pop(RANGE_G);
points[i * 2 + 1].b = b.pop(RANGE_B);
points[i * 2 + 1].s = b.pop(RANGE_S);
points[i * 2].y = y1;
points[i * 2].x = x1;
points[i * 2].r = b.pop(RANGE_R);
points[i * 2].g = b.pop(RANGE_G);
points[i * 2].b = b.pop(RANGE_B);
points[i * 2].s = b.pop(RANGE_S);
}
else
{
points[i].y = b.pop(RANGE_Y);
points[i].x = b.pop(RANGE_X);
points[i].r = b.pop(RANGE_R);
points[i].g = b.pop(RANGE_G);
points[i].b = b.pop(RANGE_B);
points[i].s = b.pop(RANGE_S);
}
}
npoints = dw * dh * POINTS_PER_CELL;
/* Render these points to a new image */
dst = pipi_new(width, height);
render(dst, 0, 0, width, height);
/* Save image and bail out */
pipi_save(dst, dstname);
pipi_free(dst);
}
return EXIT_SUCCESS;
}