2 // Copyright (C) 2009 Mozilla Foundation
4 // Permission is hereby granted, free of charge, to any person obtaining
5 // a copy of this software and associated documentation files (the "Software"),
6 // to deal in the Software without restriction, including without limitation
7 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 // and/or sell copies of the Software, and to permit persons to whom the Software
9 // is furnished to do so, subject to the following conditions:
11 // The above copyright notice and this permission notice shall be included in
12 // all copies or substantial portions of the Software.
14 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
15 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
16 // THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
17 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
18 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
19 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
20 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22 #define _ISOC99_SOURCE /* for INFINITY */
26 #include <string.h> //memcpy
28 #include "transform_util.h"
31 #if !defined(INFINITY)
32 #define INFINITY HUGE_VAL
35 #define PARAMETRIC_CURVE_TYPE 0x70617261 //'para'
37 /* value must be a value between 0 and 1 */
38 //XXX: is the above a good restriction to have?
39 float lut_interp_linear(double value
, uint16_t *table
, size_t length
)
42 value
= value
* (length
- 1); // scale to length of the array
45 //XXX: can we be more performant here?
46 value
= table
[upper
]*(1. - (upper
- value
)) + table
[lower
]*(upper
- value
);
48 return value
* (1./65535.);
51 /* same as above but takes and returns a uint16_t value representing a range from 0..1 */
52 uint16_t lut_interp_linear16(uint16_t input_value
, uint16_t *table
, size_t length
)
54 /* Start scaling input_value to the length of the array: 65535*(length-1).
55 * We'll divide out the 65535 next */
56 uintptr_t value
= (input_value
* (length
- 1));
57 uint32_t upper
= (value
+ 65534) / 65535; /* equivalent to ceil(value/65535) */
58 uint32_t lower
= value
/ 65535; /* equivalent to floor(value/65535) */
59 /* interp is the distance from upper to value scaled to 0..65535 */
60 uint32_t interp
= value
% 65535;
62 value
= (table
[upper
]*(interp
) + table
[lower
]*(65535 - interp
))/65535; // 0..65535*65535
67 /* same as above but takes an input_value from 0..PRECACHE_OUTPUT_MAX
68 * and returns a uint8_t value representing a range from 0..1 */
70 uint8_t lut_interp_linear_precache_output(uint32_t input_value
, uint16_t *table
, size_t length
)
72 /* Start scaling input_value to the length of the array: PRECACHE_OUTPUT_MAX*(length-1).
73 * We'll divide out the PRECACHE_OUTPUT_MAX next */
74 uintptr_t value
= (input_value
* (length
- 1));
76 /* equivalent to ceil(value/PRECACHE_OUTPUT_MAX) */
77 uint32_t upper
= (value
+ PRECACHE_OUTPUT_MAX
-1) / PRECACHE_OUTPUT_MAX
;
78 /* equivalent to floor(value/PRECACHE_OUTPUT_MAX) */
79 uint32_t lower
= value
/ PRECACHE_OUTPUT_MAX
;
80 /* interp is the distance from upper to value scaled to 0..PRECACHE_OUTPUT_MAX */
81 uint32_t interp
= value
% PRECACHE_OUTPUT_MAX
;
83 /* the table values range from 0..65535 */
84 value
= (table
[upper
]*(interp
) + table
[lower
]*(PRECACHE_OUTPUT_MAX
- interp
)); // 0..(65535*PRECACHE_OUTPUT_MAX)
87 value
+= (PRECACHE_OUTPUT_MAX
*65535/255)/2;
88 value
/= (PRECACHE_OUTPUT_MAX
*65535/255); // scale to 0..255
92 /* value must be a value between 0 and 1 */
93 //XXX: is the above a good restriction to have?
94 float lut_interp_linear_float(float value
, float *table
, size_t length
)
97 value
= value
* (length
- 1);
100 //XXX: can we be more performant here?
101 value
= table
[upper
]*(1. - (upper
- value
)) + table
[lower
]*(upper
- value
);
102 /* scale the value */
107 /* if we use a different representation i.e. one that goes from 0 to 0x1000 we can be more efficient
108 * because we can avoid the divisions and use a shifting instead */
109 /* same as above but takes and returns a uint16_t value representing a range from 0..1 */
110 uint16_t lut_interp_linear16(uint16_t input_value
, uint16_t *table
, int length
)
112 uint32_t value
= (input_value
* (length
- 1));
113 uint32_t upper
= (value
+ 4095) / 4096; /* equivalent to ceil(value/4096) */
114 uint32_t lower
= value
/ 4096; /* equivalent to floor(value/4096) */
115 uint32_t interp
= value
% 4096;
117 value
= (table
[upper
]*(interp
) + table
[lower
]*(4096 - interp
))/4096; // 0..4096*4096
123 void compute_curve_gamma_table_type1(float gamma_table
[256], double gamma
)
126 for (i
= 0; i
< 256; i
++) {
127 gamma_table
[i
] = pow(i
/255., gamma
);
131 void compute_curve_gamma_table_type2(float gamma_table
[256], uint16_t *table
, int length
)
134 for (i
= 0; i
< 256; i
++) {
135 gamma_table
[i
] = lut_interp_linear(i
/255., table
, length
);
139 void compute_curve_gamma_table_type_parametric(float gamma_table
[256], float parameter
[7], int count
)
144 float y
= parameter
[0];
151 interval
= -INFINITY
;
152 } else if(count
== 1) {
158 interval
= -1 * parameter
[2] / parameter
[1];
159 } else if(count
== 2) {
165 interval
= -1 * parameter
[2] / parameter
[1];
166 } else if(count
== 3) {
172 interval
= parameter
[4];
173 } else if(count
== 4) {
177 e
= parameter
[5] - c
;
179 interval
= parameter
[4];
181 assert(0 && "invalid parametric function type.");
187 interval
= -INFINITY
;
189 for (X
= 0; X
< 256; X
++) {
191 // XXX The equations are not exactly as definied in the spec but are
192 // algebraic equivilent.
193 // TODO Should division by 255 be for the whole expression.
194 gamma_table
[X
] = pow(a
* X
/ 255. + b
, y
) + c
+ e
;
196 gamma_table
[X
] = c
* X
/ 255. + f
;
201 void compute_curve_gamma_table_type0(float gamma_table
[256])
204 for (i
= 0; i
< 256; i
++) {
205 gamma_table
[i
] = i
/255.;
210 float clamp_float(float a
)
220 unsigned char clamp_u8(float v
)
230 float u8Fixed8Number_to_float(uint16_t x
)
234 // 0xffff = 255 + 255/256
238 /* The SSE2 code uses min & max which let NaNs pass through.
239 We want to try to prevent that here by ensuring that
240 gamma table is within expected values. */
241 void validate_gamma_table(float gamma_table
[256])
244 for (i
= 0; i
< 256; i
++) {
245 // Note: we check that the gamma is not in range
246 // instead of out of range so that we catch NaNs
247 if (!(gamma_table
[i
] >= 0.f
&& gamma_table
[i
] <= 1.f
)) {
248 gamma_table
[i
] = 0.f
;
253 float *build_input_gamma_table(struct curveType
*TRC
)
257 if (!TRC
) return NULL
;
258 gamma_table
= malloc(sizeof(float)*256);
260 if (TRC
->type
== PARAMETRIC_CURVE_TYPE
) {
261 compute_curve_gamma_table_type_parametric(gamma_table
, TRC
->parameter
, TRC
->count
);
263 if (TRC
->count
== 0) {
264 compute_curve_gamma_table_type0(gamma_table
);
265 } else if (TRC
->count
== 1) {
266 compute_curve_gamma_table_type1(gamma_table
, u8Fixed8Number_to_float(TRC
->data
[0]));
268 compute_curve_gamma_table_type2(gamma_table
, TRC
->data
, TRC
->count
);
273 validate_gamma_table(gamma_table
);
278 struct matrix
build_colorant_matrix(qcms_profile
*p
)
280 struct matrix result
;
281 result
.m
[0][0] = s15Fixed16Number_to_float(p
->redColorant
.X
);
282 result
.m
[0][1] = s15Fixed16Number_to_float(p
->greenColorant
.X
);
283 result
.m
[0][2] = s15Fixed16Number_to_float(p
->blueColorant
.X
);
284 result
.m
[1][0] = s15Fixed16Number_to_float(p
->redColorant
.Y
);
285 result
.m
[1][1] = s15Fixed16Number_to_float(p
->greenColorant
.Y
);
286 result
.m
[1][2] = s15Fixed16Number_to_float(p
->blueColorant
.Y
);
287 result
.m
[2][0] = s15Fixed16Number_to_float(p
->redColorant
.Z
);
288 result
.m
[2][1] = s15Fixed16Number_to_float(p
->greenColorant
.Z
);
289 result
.m
[2][2] = s15Fixed16Number_to_float(p
->blueColorant
.Z
);
290 result
.invalid
= false;
294 /* The following code is copied nearly directly from lcms.
295 * I think it could be much better. For example, Argyll seems to have better code in
296 * icmTable_lookup_bwd and icmTable_setup_bwd. However, for now this is a quick way
297 * to a working solution and allows for easy comparing with lcms. */
298 uint16_fract_t
lut_inverse_interp16(uint16_t Value
, uint16_t LutTable
[], int length
)
302 int x
= 0, res
; // 'int' Give spacing for negative values
303 int NumZeroes
, NumPoles
;
306 double y0
, y1
, x0
, x1
;
309 // July/27 2001 - Expanded to handle degenerated curves with an arbitrary
310 // number of elements containing 0 at the begining of the table (Zeroes)
311 // and another arbitrary number of poles (FFFFh) at the end.
312 // First the zero and pole extents are computed, then value is compared.
315 while (LutTable
[NumZeroes
] == 0 && NumZeroes
< length
-1)
318 // There are no zeros at the beginning and we are trying to find a zero, so
319 // return anything. It seems zero would be the less destructive choice
320 /* I'm not sure that this makes sense, but oh well... */
321 if (NumZeroes
== 0 && Value
== 0)
325 while (LutTable
[length
-1- NumPoles
] == 0xFFFF && NumPoles
< length
-1)
328 // Does the curve belong to this case?
329 if (NumZeroes
> 1 || NumPoles
> 1)
333 // Identify if value fall downto 0 or FFFF zone
334 if (Value
== 0) return 0;
335 // if (Value == 0xFFFF) return 0xFFFF;
337 // else restrict to valid zone
339 a
= ((NumZeroes
-1) * 0xFFFF) / (length
-1);
340 b
= ((length
-1 - NumPoles
) * 0xFFFF) / (length
-1);
347 // Seems not a degenerated case... apply binary search
353 res
= (int) lut_interp_linear16((uint16_fract_t
) (x
-1), LutTable
, length
);
357 // Found exact match.
359 return (uint16_fract_t
) (x
- 1);
362 if (res
> Value
) r
= x
- 1;
366 // Not found, should we interpolate?
369 // Get surrounding nodes
371 val2
= (length
-1) * ((double) (x
- 1) / 65535.0);
373 cell0
= (int) floor(val2
);
374 cell1
= (int) ceil(val2
);
376 if (cell0
== cell1
) return (uint16_fract_t
) x
;
378 y0
= LutTable
[cell0
] ;
379 x0
= (65535.0 * cell0
) / (length
-1);
381 y1
= LutTable
[cell1
] ;
382 x1
= (65535.0 * cell1
) / (length
-1);
384 a
= (y1
- y0
) / (x1
- x0
);
387 if (fabs(a
) < 0.01) return (uint16_fract_t
) x
;
389 f
= ((Value
- b
) / a
);
391 if (f
< 0.0) return (uint16_fract_t
) 0;
392 if (f
>= 65535.0) return (uint16_fract_t
) 0xFFFF;
394 return (uint16_fract_t
) floor(f
+ 0.5);
399 The number of entries needed to invert a lookup table should not
400 necessarily be the same as the original number of entries. This is
401 especially true of lookup tables that have a small number of entries.
405 {0, 3104, 14263, 34802, 65535}
406 invert_lut will produce an inverse of:
407 {3, 34459, 47529, 56801, 65535}
408 which has an maximum error of about 9855 (pixel difference of ~38.346)
410 For now, we punt the decision of output size to the caller. */
411 static uint16_t *invert_lut(uint16_t *table
, int length
, size_t out_length
)
414 /* for now we invert the lut by creating a lut of size out_length
415 * and attempting to lookup a value for each entry using lut_inverse_interp16 */
416 uint16_t *output
= malloc(sizeof(uint16_t)*out_length
);
420 for (i
= 0; i
< out_length
; i
++) {
421 double x
= ((double) i
* 65535.) / (double) (out_length
- 1);
422 uint16_fract_t input
= floor(x
+ .5);
423 output
[i
] = lut_inverse_interp16(input
, table
, length
);
428 static void compute_precache_pow(uint8_t *output
, float gamma
)
431 for (v
= 0; v
< PRECACHE_OUTPUT_SIZE
; v
++) {
432 //XXX: don't do integer/float conversion... and round?
433 output
[v
] = 255. * pow(v
/(double)PRECACHE_OUTPUT_MAX
, gamma
);
437 void compute_precache_lut(uint8_t *output
, uint16_t *table
, int length
)
440 for (v
= 0; v
< PRECACHE_OUTPUT_SIZE
; v
++) {
441 output
[v
] = lut_interp_linear_precache_output(v
, table
, length
);
445 void compute_precache_linear(uint8_t *output
)
448 for (v
= 0; v
< PRECACHE_OUTPUT_SIZE
; v
++) {
450 output
[v
] = v
/ (PRECACHE_OUTPUT_SIZE
/256);
454 qcms_bool
compute_precache(struct curveType
*trc
, uint8_t *output
)
457 if (trc
->type
== PARAMETRIC_CURVE_TYPE
) {
458 float gamma_table
[256];
459 uint16_t gamma_table_uint
[256];
462 int inverted_size
= 256;
464 compute_curve_gamma_table_type_parametric(gamma_table
, trc
->parameter
, trc
->count
);
465 for(i
= 0; i
< 256; i
++) {
466 gamma_table_uint
[i
] = (uint16_t)(gamma_table
[i
] * 65535);
469 //XXX: the choice of a minimum of 256 here is not backed by any theory,
470 // measurement or data, howeve r it is what lcms uses.
471 // the maximum number we would need is 65535 because that's the
472 // accuracy used for computing the pre cache table
473 if (inverted_size
< 256)
476 inverted
= invert_lut(gamma_table_uint
, 256, inverted_size
);
479 compute_precache_lut(output
, inverted
, inverted_size
);
482 if (trc
->count
== 0) {
483 compute_precache_linear(output
);
484 } else if (trc
->count
== 1) {
485 compute_precache_pow(output
, 1./u8Fixed8Number_to_float(trc
->data
[0]));
488 int inverted_size
= trc
->count
;
489 //XXX: the choice of a minimum of 256 here is not backed by any theory,
490 // measurement or data, howeve r it is what lcms uses.
491 // the maximum number we would need is 65535 because that's the
492 // accuracy used for computing the pre cache table
493 if (inverted_size
< 256)
496 inverted
= invert_lut(trc
->data
, trc
->count
, inverted_size
);
499 compute_precache_lut(output
, inverted
, inverted_size
);
507 static uint16_t *build_linear_table(int length
)
510 uint16_t *output
= malloc(sizeof(uint16_t)*length
);
514 for (i
= 0; i
< length
; i
++) {
515 double x
= ((double) i
* 65535.) / (double) (length
- 1);
516 uint16_fract_t input
= floor(x
+ .5);
522 static uint16_t *build_pow_table(float gamma
, int length
)
525 uint16_t *output
= malloc(sizeof(uint16_t)*length
);
529 for (i
= 0; i
< length
; i
++) {
530 uint16_fract_t result
;
531 double x
= ((double) i
) / (double) (length
- 1);
532 x
= pow(x
, gamma
); //XXX turn this conversion into a function
533 result
= floor(x
*65535. + .5);
539 void build_output_lut(struct curveType
*trc
,
540 uint16_t **output_gamma_lut
, size_t *output_gamma_lut_length
)
542 if (trc
->type
== PARAMETRIC_CURVE_TYPE
) {
543 float gamma_table
[256];
545 uint16_t *output
= malloc(sizeof(uint16_t)*256);
548 *output_gamma_lut
= NULL
;
552 compute_curve_gamma_table_type_parametric(gamma_table
, trc
->parameter
, trc
->count
);
553 *output_gamma_lut_length
= 256;
554 for(i
= 0; i
< 256; i
++) {
555 output
[i
] = (uint16_t)(gamma_table
[i
] * 65535);
557 *output_gamma_lut
= output
;
559 if (trc
->count
== 0) {
560 *output_gamma_lut
= build_linear_table(4096);
561 *output_gamma_lut_length
= 4096;
562 } else if (trc
->count
== 1) {
563 float gamma
= 1./u8Fixed8Number_to_float(trc
->data
[0]);
564 *output_gamma_lut
= build_pow_table(gamma
, 4096);
565 *output_gamma_lut_length
= 4096;
567 //XXX: the choice of a minimum of 256 here is not backed by any theory,
568 // measurement or data, however it is what lcms uses.
569 *output_gamma_lut_length
= trc
->count
;
570 if (*output_gamma_lut_length
< 256)
571 *output_gamma_lut_length
= 256;
573 *output_gamma_lut
= invert_lut(trc
->data
, trc
->count
, *output_gamma_lut_length
);