[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];
  i_img_dim x, y;
  int i, j;
  int ilimit;
  i_img *im = NULL;

  mm_log((1,"i_convert(im %p, 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];
8d14daab	68	i_img_dim x, y;
f5991c03	69	int i, j;
a743c0a6	70	int ilimit;
d5477d3d	71	i_img *im = NULL;
f5991c03	72
8d14daab TC	73	mm_log((1,"i_convert(im %p, src %p, coeff %p,outchan %d, inchan %d)\n",
8d14daab TC	74	im, src, coeff, outchan, inchan));
f5991c03 TC	75
	76	i_clear_error();
	77
	78	ilimit = inchan;
	79	if (ilimit > src->channels)
	80	ilimit = src->channels;
	81	if (outchan > MAXCHANNELS) {
	82	i_push_error(0, "cannot have outchan > MAXCHANNELS");
	83	return 0;
	84	}
	85
d5477d3d	86	if (src->type == i_direct_type) {
2a2c791f	87	struct chan_copy info;
d5477d3d	88	im = i_sametype_chans(src, src->xsize, src->ysize, outchan);
62869327	89
2a2c791f TC	90	if (is_channel_copy(src, coeff, outchan, inchan, &info)) {
	91	return convert_via_copy(im, src, &info);
	92	}
	93	else {
	94	#code src->bits <= i_8_bits
	95	IM_COLOR *vals;
	96
	97	/* we can always allocate a single scanline of i_color */
	98	vals = mymalloc(sizeof(IM_COLOR) * src->xsize); /* checked 04Jul05 tonyc */
	99	for (y = 0; y < src->ysize; ++y) {
	100	IM_GLIN(src, 0, src->xsize, y, vals);
	101	for (x = 0; x < src->xsize; ++x) {
	102	for (j = 0; j < outchan; ++j) {
	103	work[j] = 0;
	104	for (i = 0; i < ilimit; ++i) {
	105	work[j] += coeff[i+inchanj] vals[x].channel[i];
	106	}
	107	if (i < inchan) {
	108	work[j] += coeff[i+inchanj] IM_SAMPLE_MAX;
	109	}
62869327	110	}
2a2c791f TC	111	for (j = 0; j < outchan; ++j) {
	112	if (work[j] < 0)
	113	vals[x].channel[j] = 0;
	114	else if (work[j] >= IM_SAMPLE_MAX)
	115	vals[x].channel[j] = IM_SAMPLE_MAX;
	116	else
	117	vals[x].channel[j] = work[j];
62869327 TC	118	}
62869327 TC	119	}
2a2c791f	120	IM_PLIN(im, 0, src->xsize, y, vals);
faa9b3e7	121	}
2a2c791f	122	myfree(vals);
62869327	123	#/code
2a2c791f	124	}
f5991c03	125	}
faa9b3e7 TC	126	else {
	127	int count;
	128	int outcount;
	129	int index;
	130	i_color *colors;
	131	i_palidx *vals;
	132
d5477d3d TC	133	im = i_img_pal_new(src->xsize, src->ysize, outchan,
	134	i_maxcolors(src));
	135
faa9b3e7 TC	136	/* just translate the color table */
	137	count = i_colorcount(src);
	138	outcount = i_colorcount(im);
f0960b14 TC	139	/* color table allocated for image, so it must fit */
f0960b14 TC	140	colors = mymalloc(count * sizeof(i_color)); /* check 04Jul05 tonyc */
faa9b3e7 TC	141	i_getcolors(src, 0, colors, count);
faa9b3e7 TC	142	for (index = 0; index < count; ++index) {
f5991c03	143	for (j = 0; j < outchan; ++j) {
faa9b3e7 TC	144	work[j] = 0;
	145	for (i = 0; i < ilimit; ++i) {
	146	work[j] += coeff[i+inchanj] colors[index].channel[i];
	147	}
	148	if (i < inchan) {
	149	work[j] += coeff[i+inchanj] 255.9;
	150	}
f5991c03 TC	151	}
f5991c03 TC	152	for (j = 0; j < outchan; ++j) {
faa9b3e7 TC	153	if (work[j] < 0)
	154	colors[index].channel[j] = 0;
	155	else if (work[j] >= 255)
	156	colors[index].channel[j] = 255;
	157	else
	158	colors[index].channel[j] = work[j];
f5991c03 TC	159	}
f5991c03 TC	160	}
faa9b3e7 TC	161	if (count < outcount) {
	162	i_setcolors(im, 0, colors, count);
	163	}
	164	else {
	165	i_setcolors(im, 0, colors, outcount);
	166	i_addcolors(im, colors, count-outcount);
	167	}
	168	/* and copy the indicies */
f0960b14 TC	169	/* i_palidx is always unsigned char and will never be bigger than short
	170	and since a line of 4-byte i_colors can fit then a line of i_palidx
	171	will fit */
	172	vals = mymalloc(sizeof(i_palidx) * im->xsize); /* checked 4jul05 tonyc */
faa9b3e7 TC	173	for (y = 0; y < im->ysize; ++y) {
	174	i_gpal(src, 0, im->xsize, y, vals);
	175	i_ppal(im, 0, im->xsize, y, vals);
	176	}
a73aeb5f AMH	177	myfree(vals);
a73aeb5f AMH	178	myfree(colors);
f5991c03	179	}
faa9b3e7	180
d5477d3d	181	return im;
f5991c03 TC	182	}
f5991c03 TC	183
2a2c791f TC	184	/*
	185	=item is_channel_copy(coeff, outchan, inchan, chan_copy_info)
	186
	187	Test if the coefficients represent just copying channels around, and
	188	initialize lists of the channels to copy, zero or set to max.
	189
	190	=cut
	191	*/
	192
	193	static
	194	int is_channel_copy(i_img im, const double coeff, int outchan, int inchan,
	195	struct chan_copy *info) {
	196	int srcchan[MAXCHANNELS];
	197	int onechan[MAXCHANNELS];
	198	int i, j;
	199	int ilimit = im->channels > inchan ? inchan : im->channels;
	200
	201	for (j = 0; j < outchan; ++j) {
	202	srcchan[j] = -1;
	203	onechan[j] = 0;
	204	}
	205
	206	for (j = 0; j < outchan; ++j) {
	207	for (i = 0; i < ilimit; ++i) {
	208	if (coeff[i+inchan*j] == 1.0) {
	209	if (srcchan[j] != -1) {
	210	/* from two or more channels, not a copy */
	211	return 0;
	212	}
	213	srcchan[j] = i;
	214	}
	215	else if (coeff[i+inchan*j]) {
	216	/* some other non-zero value, not a copy */
	217	return 0;
	218	}
	219	}
	220	if (i < inchan) {
	221	if (coeff[i+inchan*j] == 1.0) {
	222	if (srcchan[j] != -1) {
	223	/* can't do both */
	224	return 0;
	225	}
	226	onechan[j] = 1;
	227	}
	228	else if (coeff[i+inchan*j]) {
	229	/* some other non-zero value, not a copy */
	230	return 0;
	231	}
	232	}
	233	}
	234
	235	/* build our working data structures */
	236	info->copy_count = info->zero_count = info->one_count = 0;
	237	for (j = 0; j < outchan; ++j) {
	238	if (srcchan[j] != -1) {
	239	info->from[info->copy_count] = srcchan[j];
	240	info->to[info->copy_count] = j;
	241	++info->copy_count;
	242	}
	243	else if (onechan[j]) {
	244	info->one[info->one_count] = j;
	245	++info->one_count;
	246	}
	247	else {
248	info->zero[info->zero_count] = j;
249	++info->zero_count;
250	}
251	}
252
253	#if 0
254	{
255	for (i = 0; i < info->copy_count; ++i) {
256	printf("From %d to %d\n", info->from[i], info->to[i]);
257	}
258	for (i = 0; i < info->one_count; ++i) {
259	printf("One %d\n", info->one[i]);
260	}
261	for (i = 0; i < info->zero_count; ++i) {
262	printf("Zero %d\n", info->zero[i]);
263	}
264	fflush(stdout);
265	}
266	#endif
267
268	return 1;
269	}
270
271	/*
272	=item convert_via_copy(im, src, chan_copy_info)
273
274	Perform a convert that only requires channel copies.
275
276	=cut
277	*/
278
279	i_img *
280	convert_via_copy(i_img im, i_img src, struct chan_copy *info) {
281	#code src->bits <= i_8_bits
282	IM_COLOR in_line = mymalloc(sizeof(IM_COLOR) src->xsize);
283	IM_COLOR out_line = mymalloc(sizeof(IM_COLOR) src->xsize);
284	i_img_dim x, y;
285	int i;
286	IM_COLOR inp, outp;
287
288	for (y = 0; y < src->ysize; ++y) {
289	IM_GLIN(src, 0, src->xsize, y, in_line);
290
291	inp = in_line;
292	outp = out_line;
293	for (x = 0; x < src->xsize; ++x) {
294	for (i = 0; i < info->copy_count; ++i) {
295	outp->channel[info->to[i]] = inp->channel[info->from[i]];
296	}
297	for (i = 0; i < info->one_count; ++i) {
298	outp->channel[info->one[i]] = IM_SAMPLE_MAX;
299	}
300	for (i = 0; i < info->zero_count; ++i) {
301	outp->channel[info->zero[i]] = 0;
302	}
303	++inp;
304	++outp;
305	}
306
307	IM_PLIN(im, 0, src->xsize, y, out_line);
308	}
309
310	myfree(in_line);
311	myfree(out_line);
312	#/code
313
314	return im;
315	}
316
f5991c03 TC	317	/*
	318	=back
	319
	320	=head1 SEE ALSO
	321
	322	Imager(3)
	323
	324	=head1 AUTHOR
	325
	326	Tony Cook <tony@develop-help.com>
	327
	328	=cut
	329	*/