[imager.git] / convert.im

/*
=head1 NAME

  convert.im - image conversions

=head1 SYNOPSIS

  out = i_convert(srcimage, coeff, outchans, inchans)

=head1 DESCRIPTION

Converts images from one format to another, typically in this case for
converting from RGBA to greyscale and back.

=over

=cut
*/

#include "imager.h"

struct chan_copy {
  /* channels to copy */
  int copy_count;
  int from[MAXCHANNELS];
  int to[MAXCHANNELS];

  /* channels to zero */
  int zero_count;
  int zero[MAXCHANNELS];

  /* channels to set to maxsample */
  int one_count;
  int one[MAXCHANNELS];
};

static int 
is_channel_copy(i_img *im, const double *coeff, 
		int outchan, int inchan, 
		struct chan_copy *info);

static i_img *
convert_via_copy(i_img *im, i_img *src, struct chan_copy *info);

/*
=item i_convert(src, coeff, outchan, inchan)

Converts the image src into another image.

coeff contains the co-efficients of an outchan x inchan matrix, for
each output pixel:

              coeff[0], coeff[1] ...
  im[x,y] = [ coeff[inchan], coeff[inchan+1]...        ] * [ src[x,y], 1]
              ...              coeff[inchan*outchan-1]

If im has the wrong number of channels or is the wrong size then
i_convert() will re-create it.

Now handles images with more than 8-bits/sample.

=cut
*/

i_img *
i_convert(i_img *src, const double *coeff, int outchan, int inchan) {
  double work[MAXCHANNELS];
  int x, y;
  int i, j;
  int ilimit;
  i_img *im = NULL;

  mm_log((1,"i_convert(src %p, coeff %p,outchan %d, inchan %d)\n",im,src, coeff,outchan, inchan));
 
  i_clear_error();

  ilimit = inchan;
  if (ilimit > src->channels)
    ilimit = src->channels;
  if (outchan > MAXCHANNELS) {
    i_push_error(0, "cannot have outchan > MAXCHANNELS");
    return 0;
  }

  if (src->type == i_direct_type) {
    struct chan_copy info;
    im = i_sametype_chans(src, src->xsize, src->ysize, outchan);
    
    if (is_channel_copy(src, coeff, outchan, inchan, &info)) {
      return convert_via_copy(im, src, &info);
    }
    else {
#code src->bits <= i_8_bits
      IM_COLOR *vals;
      
      /* we can always allocate a single scanline of i_color */
      vals = mymalloc(sizeof(IM_COLOR) * src->xsize); /* checked 04Jul05 tonyc */
      for (y = 0; y < src->ysize; ++y) {
	IM_GLIN(src, 0, src->xsize, y, vals);
	for (x = 0; x < src->xsize; ++x) {
	  for (j = 0; j < outchan; ++j) {
	    work[j] = 0;
	    for (i = 0; i < ilimit; ++i) {
	      work[j] += coeff[i+inchan*j] * vals[x].channel[i];
	    }
	    if (i < inchan) {
	      work[j] += coeff[i+inchan*j] * IM_SAMPLE_MAX;
	    }
	  }
	  for (j = 0; j < outchan; ++j) {
	    if (work[j] < 0)
	      vals[x].channel[j] = 0;
	    else if (work[j] >= IM_SAMPLE_MAX)
	      vals[x].channel[j] = IM_SAMPLE_MAX;
	    else
	      vals[x].channel[j] = work[j];
	  }
	}
	IM_PLIN(im, 0, src->xsize, y, vals);
      }
      myfree(vals);
#/code
    }
  }
  else {
    int count;
    int outcount;
    int index;
    i_color *colors;
    i_palidx *vals;

    im = i_img_pal_new(src->xsize, src->ysize, outchan, 
		       i_maxcolors(src));

    /* just translate the color table */
    count = i_colorcount(src);
    outcount = i_colorcount(im);
    /* color table allocated for image, so it must fit */
    colors = mymalloc(count * sizeof(i_color)); /* check 04Jul05 tonyc */
    i_getcolors(src, 0, colors, count);
    for (index = 0; index < count; ++index) {
      for (j = 0; j < outchan; ++j) {
        work[j] = 0;
        for (i = 0; i < ilimit; ++i) {
          work[j] += coeff[i+inchan*j] * colors[index].channel[i];
        }
        if (i < inchan) {
          work[j] += coeff[i+inchan*j] * 255.9;
        }
      }
      for (j = 0; j < outchan; ++j) {
        if (work[j] < 0)
          colors[index].channel[j] = 0;
        else if (work[j] >= 255)
          colors[index].channel[j] = 255;
        else
          colors[index].channel[j] = work[j];
      }
    }
    if (count < outcount) {
      i_setcolors(im, 0, colors, count);
    }
    else {
      i_setcolors(im, 0, colors, outcount);
      i_addcolors(im, colors, count-outcount);
    }
    /* and copy the indicies */
    /* i_palidx is always unsigned char and will never be bigger than short
       and since a line of 4-byte i_colors can fit then a line of i_palidx
       will fit */
    vals = mymalloc(sizeof(i_palidx) * im->xsize); /* checked 4jul05 tonyc */
    for (y = 0; y < im->ysize; ++y) {
      i_gpal(src, 0, im->xsize, y, vals);
      i_ppal(im, 0, im->xsize, y, vals);
    }
    myfree(vals);
    myfree(colors);
  }

  return im;
}

/*
=item is_channel_copy(coeff, outchan, inchan, chan_copy_info)

Test if the coefficients represent just copying channels around, and
initialize lists of the channels to copy, zero or set to max.

=cut
*/

static
int is_channel_copy(i_img *im, const double *coeff, int outchan, int inchan, 
		    struct chan_copy *info) {
  int srcchan[MAXCHANNELS];
  int onechan[MAXCHANNELS];
  int i, j;
  int ilimit = im->channels > inchan ? inchan : im->channels;

  for (j = 0; j < outchan; ++j) {
    srcchan[j] = -1;
    onechan[j] = 0;
  }

  for (j = 0; j < outchan; ++j) {
    for (i = 0; i < ilimit; ++i) {
      if (coeff[i+inchan*j] == 1.0) {
	if (srcchan[j] != -1) {
	  /* from two or more channels, not a copy */
	  return 0;
	}
	srcchan[j] = i;
      }
      else if (coeff[i+inchan*j]) {
	/* some other non-zero value, not a copy */
	return 0;
      }
    }
    if (i < inchan) {
      if (coeff[i+inchan*j] == 1.0) {
	if (srcchan[j] != -1) {
	  /* can't do both */
	  return 0;
	}
	onechan[j] = 1;
      }
      else if (coeff[i+inchan*j]) {
	/* some other non-zero value, not a copy */
	return 0;
      }
    }
  }

  /* build our working data structures */
  info->copy_count = info->zero_count = info->one_count = 0;
  for (j = 0; j < outchan; ++j) {
    if (srcchan[j] != -1) {
      info->from[info->copy_count] = srcchan[j];
      info->to[info->copy_count] = j;
      ++info->copy_count;
    }
    else if (onechan[j]) {
      info->one[info->one_count] = j;
      ++info->one_count;
    }
    else {
      info->zero[info->zero_count] = j;
      ++info->zero_count;
    }
  }

#if 0
  {
    for (i = 0; i < info->copy_count; ++i) {
      printf("From %d to %d\n", info->from[i], info->to[i]);
    }
    for (i = 0; i < info->one_count; ++i) {
      printf("One %d\n", info->one[i]);
    }
    for (i = 0; i < info->zero_count; ++i) {
      printf("Zero %d\n", info->zero[i]);
    }
    fflush(stdout);
  }
#endif

  return 1;
}

/*
=item convert_via_copy(im, src, chan_copy_info)

Perform a convert that only requires channel copies.

=cut
*/

i_img *
convert_via_copy(i_img *im, i_img *src, struct chan_copy *info) {
#code src->bits <= i_8_bits
  IM_COLOR *in_line = mymalloc(sizeof(IM_COLOR) * src->xsize);
  IM_COLOR *out_line = mymalloc(sizeof(IM_COLOR) * src->xsize);
  i_img_dim x, y;
  int i;
  IM_COLOR *inp, *outp;

  for (y = 0; y < src->ysize; ++y) {
    IM_GLIN(src, 0, src->xsize, y, in_line);

    inp = in_line;
    outp = out_line;
    for (x = 0; x < src->xsize; ++x) {
      for (i = 0; i < info->copy_count; ++i) {
	outp->channel[info->to[i]] = inp->channel[info->from[i]];
      }
      for (i = 0; i < info->one_count; ++i) {
	outp->channel[info->one[i]] = IM_SAMPLE_MAX;
      }
      for (i = 0; i < info->zero_count; ++i) {
	outp->channel[info->zero[i]] = 0;
      }
      ++inp;
      ++outp;
    }
    
    IM_PLIN(im, 0, src->xsize, y, out_line);
  }
  
  myfree(in_line);
  myfree(out_line);
#/code
      
  return im;
}

/*
=back

=head1 SEE ALSO

Imager(3)

=head1 AUTHOR

Tony Cook <tony@develop-help.com>

=cut
*/
Commit	Line	Data
f5991c03 TC	1	/*
	2	=head1 NAME
	3
62869327	4	convert.im - image conversions
f5991c03 TC	5
	6	=head1 SYNOPSIS
	7
55ebcc7b	8	out = i_convert(srcimage, coeff, outchans, inchans)
f5991c03 TC	9
	10	=head1 DESCRIPTION
	11
	12	Converts images from one format to another, typically in this case for
	13	converting from RGBA to greyscale and back.
	14
	15	=over
	16
	17	=cut
	18	*/
	19
92bda632	20	#include "imager.h"
f5991c03	21
2a2c791f TC	22	struct chan_copy {
	23	/* channels to copy */
	24	int copy_count;
	25	int from[MAXCHANNELS];
	26	int to[MAXCHANNELS];
	27
	28	/* channels to zero */
	29	int zero_count;
	30	int zero[MAXCHANNELS];
	31
	32	/* channels to set to maxsample */
	33	int one_count;
	34	int one[MAXCHANNELS];
	35	};
	36
	37	static int
	38	is_channel_copy(i_img im, const double coeff,
	39	int outchan, int inchan,
	40	struct chan_copy *info);
	41
	42	static i_img *
	43	convert_via_copy(i_img im, i_img src, struct chan_copy *info);
f5991c03 TC	44
f5991c03 TC	45	/*
d5477d3d	46	=item i_convert(src, coeff, outchan, inchan)
f5991c03 TC	47
	48	Converts the image src into another image.
	49
	50	coeff contains the co-efficients of an outchan x inchan matrix, for
	51	each output pixel:
	52
	53	coeff[0], coeff[1] ...
	54	im[x,y] = [ coeff[inchan], coeff[inchan+1]... ] * [ src[x,y], 1]
	55	... coeff[inchan*outchan-1]
	56
	57	If im has the wrong number of channels or is the wrong size then
	58	i_convert() will re-create it.
	59
faa9b3e7 TC	60	Now handles images with more than 8-bits/sample.
faa9b3e7 TC	61
f5991c03 TC	62	=cut
	63	*/
	64
d5477d3d	65	i_img *
62869327	66	i_convert(i_img src, const double coeff, int outchan, int inchan) {
2a2c791f	67	double work[MAXCHANNELS];
f5991c03 TC	68	int x, y;
f5991c03 TC	69	int i, j;
a743c0a6	70	int ilimit;
d5477d3d	71	i_img *im = NULL;
f5991c03	72
d5477d3d	73	mm_log((1,"i_convert(src %p, coeff %p,outchan %d, inchan %d)\n",im,src, coeff,outchan, inchan));
f5991c03 TC	74
	75	i_clear_error();
	76
	77	ilimit = inchan;
	78	if (ilimit > src->channels)
	79	ilimit = src->channels;
	80	if (outchan > MAXCHANNELS) {
	81	i_push_error(0, "cannot have outchan > MAXCHANNELS");
	82	return 0;
	83	}
	84
d5477d3d	85	if (src->type == i_direct_type) {
2a2c791f	86	struct chan_copy info;
d5477d3d	87	im = i_sametype_chans(src, src->xsize, src->ysize, outchan);
62869327	88
2a2c791f TC	89	if (is_channel_copy(src, coeff, outchan, inchan, &info)) {
	90	return convert_via_copy(im, src, &info);
	91	}
	92	else {
	93	#code src->bits <= i_8_bits
	94	IM_COLOR *vals;
	95
	96	/* we can always allocate a single scanline of i_color */
	97	vals = mymalloc(sizeof(IM_COLOR) * src->xsize); /* checked 04Jul05 tonyc */
	98	for (y = 0; y < src->ysize; ++y) {
	99	IM_GLIN(src, 0, src->xsize, y, vals);
	100	for (x = 0; x < src->xsize; ++x) {
	101	for (j = 0; j < outchan; ++j) {
	102	work[j] = 0;
	103	for (i = 0; i < ilimit; ++i) {
	104	work[j] += coeff[i+inchanj] vals[x].channel[i];
	105	}
	106	if (i < inchan) {
	107	work[j] += coeff[i+inchanj] IM_SAMPLE_MAX;
	108	}
62869327	109	}
2a2c791f TC	110	for (j = 0; j < outchan; ++j) {
	111	if (work[j] < 0)
	112	vals[x].channel[j] = 0;
	113	else if (work[j] >= IM_SAMPLE_MAX)
	114	vals[x].channel[j] = IM_SAMPLE_MAX;
	115	else
	116	vals[x].channel[j] = work[j];
62869327 TC	117	}
62869327 TC	118	}
2a2c791f	119	IM_PLIN(im, 0, src->xsize, y, vals);
faa9b3e7	120	}
2a2c791f	121	myfree(vals);
62869327	122	#/code
2a2c791f	123	}
f5991c03	124	}
faa9b3e7 TC	125	else {
	126	int count;
	127	int outcount;
	128	int index;
	129	i_color *colors;
	130	i_palidx *vals;
	131
d5477d3d TC	132	im = i_img_pal_new(src->xsize, src->ysize, outchan,
	133	i_maxcolors(src));
	134
faa9b3e7 TC	135	/* just translate the color table */
	136	count = i_colorcount(src);
	137	outcount = i_colorcount(im);
f0960b14 TC	138	/* color table allocated for image, so it must fit */
f0960b14 TC	139	colors = mymalloc(count * sizeof(i_color)); /* check 04Jul05 tonyc */
faa9b3e7 TC	140	i_getcolors(src, 0, colors, count);
faa9b3e7 TC	141	for (index = 0; index < count; ++index) {
f5991c03	142	for (j = 0; j < outchan; ++j) {
faa9b3e7 TC	143	work[j] = 0;
	144	for (i = 0; i < ilimit; ++i) {
	145	work[j] += coeff[i+inchanj] colors[index].channel[i];
	146	}
	147	if (i < inchan) {
	148	work[j] += coeff[i+inchanj] 255.9;
	149	}
f5991c03 TC	150	}
f5991c03 TC	151	for (j = 0; j < outchan; ++j) {
faa9b3e7 TC	152	if (work[j] < 0)
	153	colors[index].channel[j] = 0;
	154	else if (work[j] >= 255)
	155	colors[index].channel[j] = 255;
	156	else
	157	colors[index].channel[j] = work[j];
f5991c03 TC	158	}
f5991c03 TC	159	}
faa9b3e7 TC	160	if (count < outcount) {
	161	i_setcolors(im, 0, colors, count);
	162	}
	163	else {
	164	i_setcolors(im, 0, colors, outcount);
	165	i_addcolors(im, colors, count-outcount);
	166	}
	167	/* and copy the indicies */
f0960b14 TC	168	/* i_palidx is always unsigned char and will never be bigger than short
	169	and since a line of 4-byte i_colors can fit then a line of i_palidx
	170	will fit */
	171	vals = mymalloc(sizeof(i_palidx) * im->xsize); /* checked 4jul05 tonyc */
faa9b3e7 TC	172	for (y = 0; y < im->ysize; ++y) {
	173	i_gpal(src, 0, im->xsize, y, vals);
	174	i_ppal(im, 0, im->xsize, y, vals);
	175	}
a73aeb5f AMH	176	myfree(vals);
a73aeb5f AMH	177	myfree(colors);
f5991c03	178	}
faa9b3e7	179
d5477d3d	180	return im;
f5991c03 TC	181	}
f5991c03 TC	182
2a2c791f TC	183	/*
	184	=item is_channel_copy(coeff, outchan, inchan, chan_copy_info)
	185
	186	Test if the coefficients represent just copying channels around, and
	187	initialize lists of the channels to copy, zero or set to max.
	188
	189	=cut
	190	*/
	191
	192	static
	193	int is_channel_copy(i_img im, const double coeff, int outchan, int inchan,
	194	struct chan_copy *info) {
	195	int srcchan[MAXCHANNELS];
	196	int onechan[MAXCHANNELS];
	197	int i, j;
	198	int ilimit = im->channels > inchan ? inchan : im->channels;
	199
	200	for (j = 0; j < outchan; ++j) {
	201	srcchan[j] = -1;
	202	onechan[j] = 0;
	203	}
	204
	205	for (j = 0; j < outchan; ++j) {
	206	for (i = 0; i < ilimit; ++i) {
	207	if (coeff[i+inchan*j] == 1.0) {
	208	if (srcchan[j] != -1) {
	209	/* from two or more channels, not a copy */
	210	return 0;
	211	}
	212	srcchan[j] = i;
	213	}
	214	else if (coeff[i+inchan*j]) {
	215	/* some other non-zero value, not a copy */
	216	return 0;
	217	}
	218	}
	219	if (i < inchan) {
	220	if (coeff[i+inchan*j] == 1.0) {
	221	if (srcchan[j] != -1) {
	222	/* can't do both */
	223	return 0;
	224	}
	225	onechan[j] = 1;
	226	}
	227	else if (coeff[i+inchan*j]) {
	228	/* some other non-zero value, not a copy */
	229	return 0;
	230	}
	231	}
	232	}
	233
	234	/* build our working data structures */
	235	info->copy_count = info->zero_count = info->one_count = 0;
	236	for (j = 0; j < outchan; ++j) {
	237	if (srcchan[j] != -1) {
	238	info->from[info->copy_count] = srcchan[j];
	239	info->to[info->copy_count] = j;
	240	++info->copy_count;
	241	}
	242	else if (onechan[j]) {
	243	info->one[info->one_count] = j;
	244	++info->one_count;
	245	}
	246	else {
247	info->zero[info->zero_count] = j;
248	++info->zero_count;
249	}
250	}
251
252	#if 0
253	{
254	for (i = 0; i < info->copy_count; ++i) {
255	printf("From %d to %d\n", info->from[i], info->to[i]);
256	}
257	for (i = 0; i < info->one_count; ++i) {
258	printf("One %d\n", info->one[i]);
259	}
260	for (i = 0; i < info->zero_count; ++i) {
261	printf("Zero %d\n", info->zero[i]);
262	}
263	fflush(stdout);
264	}
265	#endif
266
267	return 1;
268	}
269
270	/*
271	=item convert_via_copy(im, src, chan_copy_info)
272
273	Perform a convert that only requires channel copies.
274
275	=cut
276	*/
277
278	i_img *
279	convert_via_copy(i_img im, i_img src, struct chan_copy *info) {
280	#code src->bits <= i_8_bits
281	IM_COLOR in_line = mymalloc(sizeof(IM_COLOR) src->xsize);
282	IM_COLOR out_line = mymalloc(sizeof(IM_COLOR) src->xsize);
283	i_img_dim x, y;
284	int i;
285	IM_COLOR inp, outp;
286
287	for (y = 0; y < src->ysize; ++y) {
288	IM_GLIN(src, 0, src->xsize, y, in_line);
289
290	inp = in_line;
291	outp = out_line;
292	for (x = 0; x < src->xsize; ++x) {
293	for (i = 0; i < info->copy_count; ++i) {
294	outp->channel[info->to[i]] = inp->channel[info->from[i]];
295	}
296	for (i = 0; i < info->one_count; ++i) {
297	outp->channel[info->one[i]] = IM_SAMPLE_MAX;
298	}
299	for (i = 0; i < info->zero_count; ++i) {
300	outp->channel[info->zero[i]] = 0;
301	}
302	++inp;
303	++outp;
304	}
305
306	IM_PLIN(im, 0, src->xsize, y, out_line);
307	}
308
309	myfree(in_line);
310	myfree(out_line);
311	#/code
312
313	return im;
314	}
315
f5991c03 TC	316	/*
	317	=back
	318
	319	=head1 SEE ALSO
	320
	321	Imager(3)
	322
	323	=head1 AUTHOR
	324
	325	Tony Cook <tony@develop-help.com>
	326
	327	=cut
	328	*/