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Diffstat (limited to 'gfx/qcms/transform_util.c')
| -rw-r--r-- | gfx/qcms/transform_util.c | 516 |
1 files changed, 516 insertions, 0 deletions
diff --git a/gfx/qcms/transform_util.c b/gfx/qcms/transform_util.c new file mode 100644 index 000000000..f15a3f1cf --- /dev/null +++ b/gfx/qcms/transform_util.c @@ -0,0 +1,516 @@ +#include <math.h> +#include <assert.h> +#include <string.h> //memcpy +#include "qcmsint.h" +#include "transform_util.h" +#include "matrix.h" + +#define PARAMETRIC_CURVE_TYPE 0x70617261 //'para' + +/* value must be a value between 0 and 1 */ +//XXX: is the above a good restriction to have? +// the output range of this functions is 0..1 +float lut_interp_linear(double input_value, uint16_t *table, int length) +{ + int upper, lower; + float value; + input_value = input_value * (length - 1); // scale to length of the array + upper = ceil(input_value); + lower = floor(input_value); + //XXX: can we be more performant here? + value = table[upper]*(1. - (upper - input_value)) + table[lower]*(upper - input_value); + /* scale the value */ + return value * (1.f/65535.f); +} + +/* same as above but takes and returns a uint16_t value representing a range from 0..1 */ +uint16_t lut_interp_linear16(uint16_t input_value, uint16_t *table, int length) +{ + /* Start scaling input_value to the length of the array: 65535*(length-1). + * We'll divide out the 65535 next */ + uint32_t value = (input_value * (length - 1)); + uint32_t upper = (value + 65534) / 65535; /* equivalent to ceil(value/65535) */ + uint32_t lower = value / 65535; /* equivalent to floor(value/65535) */ + /* interp is the distance from upper to value scaled to 0..65535 */ + uint32_t interp = value % 65535; + + value = (table[upper]*(interp) + table[lower]*(65535 - interp))/65535; // 0..65535*65535 + + return value; +} + +/* same as above but takes an input_value from 0..PRECACHE_OUTPUT_MAX + * and returns a uint8_t value representing a range from 0..1 */ +static +uint8_t lut_interp_linear_precache_output(uint32_t input_value, uint16_t *table, int length) +{ + /* Start scaling input_value to the length of the array: PRECACHE_OUTPUT_MAX*(length-1). + * We'll divide out the PRECACHE_OUTPUT_MAX next */ + uint32_t value = (input_value * (length - 1)); + + /* equivalent to ceil(value/PRECACHE_OUTPUT_MAX) */ + uint32_t upper = (value + PRECACHE_OUTPUT_MAX-1) / PRECACHE_OUTPUT_MAX; + /* equivalent to floor(value/PRECACHE_OUTPUT_MAX) */ + uint32_t lower = value / PRECACHE_OUTPUT_MAX; + /* interp is the distance from upper to value scaled to 0..PRECACHE_OUTPUT_MAX */ + uint32_t interp = value % PRECACHE_OUTPUT_MAX; + + /* the table values range from 0..65535 */ + value = (table[upper]*(interp) + table[lower]*(PRECACHE_OUTPUT_MAX - interp)); // 0..(65535*PRECACHE_OUTPUT_MAX) + + /* round and scale */ + value += (PRECACHE_OUTPUT_MAX*65535/255)/2; + value /= (PRECACHE_OUTPUT_MAX*65535/255); // scale to 0..255 + return value; +} + +/* value must be a value between 0 and 1 */ +//XXX: is the above a good restriction to have? +float lut_interp_linear_float(float value, float *table, int length) +{ + int upper, lower; + value = value * (length - 1); + upper = ceilf(value); + lower = floorf(value); + //XXX: can we be more performant here? + value = table[upper]*(1. - (upper - value)) + table[lower]*(upper - value); + /* scale the value */ + return value; +} + +#if 0 +/* if we use a different representation i.e. one that goes from 0 to 0x1000 we can be more efficient + * because we can avoid the divisions and use a shifting instead */ +/* same as above but takes and returns a uint16_t value representing a range from 0..1 */ +uint16_t lut_interp_linear16(uint16_t input_value, uint16_t *table, int length) +{ + uint32_t value = (input_value * (length - 1)); + uint32_t upper = (value + 4095) / 4096; /* equivalent to ceil(value/4096) */ + uint32_t lower = value / 4096; /* equivalent to floor(value/4096) */ + uint32_t interp = value % 4096; + + value = (table[upper]*(interp) + table[lower]*(4096 - interp))/4096; // 0..4096*4096 + + return value; +} +#endif + +void compute_curve_gamma_table_type1(float gamma_table[256], uint16_t gamma) +{ + unsigned int i; + float gamma_float = u8Fixed8Number_to_float(gamma); + for (i = 0; i < 256; i++) { + // 0..1^(0..255 + 255/256) will always be between 0 and 1 + gamma_table[i] = pow(i/255., gamma_float); + } +} + +void compute_curve_gamma_table_type2(float gamma_table[256], uint16_t *table, int length) +{ + unsigned int i; + for (i = 0; i < 256; i++) { + gamma_table[i] = lut_interp_linear(i/255., table, length); + } +} + +void compute_curve_gamma_table_type_parametric(float gamma_table[256], float parameter[7], int count) +{ + size_t X; + float interval; + float a, b, c, e, f; + float y = parameter[0]; + if (count == 0) { + a = 1; + b = 0; + c = 0; + e = 0; + f = 0; + interval = -1; + } else if(count == 1) { + a = parameter[1]; + b = parameter[2]; + c = 0; + e = 0; + f = 0; + interval = -1 * parameter[2] / parameter[1]; + } else if(count == 2) { + a = parameter[1]; + b = parameter[2]; + c = 0; + e = parameter[3]; + f = parameter[3]; + interval = -1 * parameter[2] / parameter[1]; + } else if(count == 3) { + a = parameter[1]; + b = parameter[2]; + c = parameter[3]; + e = -c; + f = 0; + interval = parameter[4]; + } else if(count == 4) { + a = parameter[1]; + b = parameter[2]; + c = parameter[3]; + e = parameter[5] - c; + f = parameter[6]; + interval = parameter[4]; + } else { + assert(0 && "invalid parametric function type."); + a = 1; + b = 0; + c = 0; + e = 0; + f = 0; + interval = -1; + } + for (X = 0; X < 256; X++) { + if (X >= interval) { + // XXX The equations are not exactly as defined in the spec but are + // algebraically equivalent. + // TODO Should division by 255 be for the whole expression. + gamma_table[X] = clamp_float(pow(a * X / 255. + b, y) + c + e); + } else { + gamma_table[X] = clamp_float(c * X / 255. + f); + } + } +} + +void compute_curve_gamma_table_type0(float gamma_table[256]) +{ + unsigned int i; + for (i = 0; i < 256; i++) { + gamma_table[i] = i/255.; + } +} + +float *build_input_gamma_table(struct curveType *TRC) +{ + float *gamma_table; + + if (!TRC) return NULL; + gamma_table = malloc(sizeof(float)*256); + if (gamma_table) { + if (TRC->type == PARAMETRIC_CURVE_TYPE) { + compute_curve_gamma_table_type_parametric(gamma_table, TRC->parameter, TRC->count); + } else { + if (TRC->count == 0) { + compute_curve_gamma_table_type0(gamma_table); + } else if (TRC->count == 1) { + compute_curve_gamma_table_type1(gamma_table, TRC->data[0]); + } else { + compute_curve_gamma_table_type2(gamma_table, TRC->data, TRC->count); + } + } + } + return gamma_table; +} + +struct matrix build_colorant_matrix(qcms_profile *p) +{ + struct matrix result; + result.m[0][0] = s15Fixed16Number_to_float(p->redColorant.X); + result.m[0][1] = s15Fixed16Number_to_float(p->greenColorant.X); + result.m[0][2] = s15Fixed16Number_to_float(p->blueColorant.X); + result.m[1][0] = s15Fixed16Number_to_float(p->redColorant.Y); + result.m[1][1] = s15Fixed16Number_to_float(p->greenColorant.Y); + result.m[1][2] = s15Fixed16Number_to_float(p->blueColorant.Y); + result.m[2][0] = s15Fixed16Number_to_float(p->redColorant.Z); + result.m[2][1] = s15Fixed16Number_to_float(p->greenColorant.Z); + result.m[2][2] = s15Fixed16Number_to_float(p->blueColorant.Z); + result.invalid = false; + return result; +} + +/* The following code is copied nearly directly from lcms. + * I think it could be much better. For example, Argyll seems to have better code in + * icmTable_lookup_bwd and icmTable_setup_bwd. However, for now this is a quick way + * to a working solution and allows for easy comparing with lcms. */ +uint16_fract_t lut_inverse_interp16(uint16_t Value, uint16_t LutTable[], int length) +{ + int l = 1; + int r = 0x10000; + int x = 0, res; // 'int' Give spacing for negative values + int NumZeroes, NumPoles; + int cell0, cell1; + double val2; + double y0, y1, x0, x1; + double a, b, f; + + // July/27 2001 - Expanded to handle degenerated curves with an arbitrary + // number of elements containing 0 at the begining of the table (Zeroes) + // and another arbitrary number of poles (FFFFh) at the end. + // First the zero and pole extents are computed, then value is compared. + + NumZeroes = 0; + while (LutTable[NumZeroes] == 0 && NumZeroes < length-1) + NumZeroes++; + + // There are no zeros at the beginning and we are trying to find a zero, so + // return anything. It seems zero would be the less destructive choice + /* I'm not sure that this makes sense, but oh well... */ + if (NumZeroes == 0 && Value == 0) + return 0; + + NumPoles = 0; + while (LutTable[length-1- NumPoles] == 0xFFFF && NumPoles < length-1) + NumPoles++; + + // Does the curve belong to this case? + if (NumZeroes > 1 || NumPoles > 1) + { + int a, b; + + // Identify if value fall downto 0 or FFFF zone + if (Value == 0) return 0; + // if (Value == 0xFFFF) return 0xFFFF; + + // else restrict to valid zone + + if (NumZeroes > 1) { + a = ((NumZeroes-1) * 0xFFFF) / (length-1); + l = a - 1; + } + if (NumPoles > 1) { + b = ((length-1 - NumPoles) * 0xFFFF) / (length-1); + r = b + 1; + } + } + + if (r <= l) { + // If this happens LutTable is not invertible + return 0; + } + + + // Seems not a degenerated case... apply binary search + while (r > l) { + + x = (l + r) / 2; + + res = (int) lut_interp_linear16((uint16_fract_t) (x-1), LutTable, length); + + if (res == Value) { + + // Found exact match. + + return (uint16_fract_t) (x - 1); + } + + if (res > Value) r = x - 1; + else l = x + 1; + } + + // Not found, should we interpolate? + + // Get surrounding nodes + + assert(x >= 1); + + val2 = (length-1) * ((double) (x - 1) / 65535.0); + + cell0 = (int) floor(val2); + cell1 = (int) ceil(val2); + + if (cell0 == cell1) return (uint16_fract_t) x; + + y0 = LutTable[cell0] ; + x0 = (65535.0 * cell0) / (length-1); + + y1 = LutTable[cell1] ; + x1 = (65535.0 * cell1) / (length-1); + + a = (y1 - y0) / (x1 - x0); + b = y0 - a * x0; + + if (fabs(a) < 0.01) return (uint16_fract_t) x; + + f = ((Value - b) / a); + + if (f < 0.0) return (uint16_fract_t) 0; + if (f >= 65535.0) return (uint16_fract_t) 0xFFFF; + + return (uint16_fract_t) floor(f + 0.5); + +} + +/* + The number of entries needed to invert a lookup table should not + necessarily be the same as the original number of entries. This is + especially true of lookup tables that have a small number of entries. + + For example: + Using a table like: + {0, 3104, 14263, 34802, 65535} + invert_lut will produce an inverse of: + {3, 34459, 47529, 56801, 65535} + which has an maximum error of about 9855 (pixel difference of ~38.346) + + For now, we punt the decision of output size to the caller. */ +static uint16_t *invert_lut(uint16_t *table, int length, int out_length) +{ + int i; + /* for now we invert the lut by creating a lut of size out_length + * and attempting to lookup a value for each entry using lut_inverse_interp16 */ + uint16_t *output = malloc(sizeof(uint16_t)*out_length); + if (!output) + return NULL; + + for (i = 0; i < out_length; i++) { + double x = ((double) i * 65535.) / (double) (out_length - 1); + uint16_fract_t input = floor(x + .5); + output[i] = lut_inverse_interp16(input, table, length); + } + return output; +} + +static void compute_precache_pow(uint8_t *output, float gamma) +{ + uint32_t v = 0; + for (v = 0; v < PRECACHE_OUTPUT_SIZE; v++) { + //XXX: don't do integer/float conversion... and round? + output[v] = 255. * pow(v/(double)PRECACHE_OUTPUT_MAX, gamma); + } +} + +void compute_precache_lut(uint8_t *output, uint16_t *table, int length) +{ + uint32_t v = 0; + for (v = 0; v < PRECACHE_OUTPUT_SIZE; v++) { + output[v] = lut_interp_linear_precache_output(v, table, length); + } +} + +void compute_precache_linear(uint8_t *output) +{ + uint32_t v = 0; + for (v = 0; v < PRECACHE_OUTPUT_SIZE; v++) { + //XXX: round? + output[v] = v / (PRECACHE_OUTPUT_SIZE/256); + } +} + +qcms_bool compute_precache(struct curveType *trc, uint8_t *output) +{ + + if (trc->type == PARAMETRIC_CURVE_TYPE) { + float gamma_table[256]; + uint16_t gamma_table_uint[256]; + uint16_t i; + uint16_t *inverted; + int inverted_size = 256; + + compute_curve_gamma_table_type_parametric(gamma_table, trc->parameter, trc->count); + for(i = 0; i < 256; i++) { + gamma_table_uint[i] = (uint16_t)(gamma_table[i] * 65535); + } + + //XXX: the choice of a minimum of 256 here is not backed by any theory, + // measurement or data, howeve r it is what lcms uses. + // the maximum number we would need is 65535 because that's the + // accuracy used for computing the pre cache table + if (inverted_size < 256) + inverted_size = 256; + + inverted = invert_lut(gamma_table_uint, 256, inverted_size); + if (!inverted) + return false; + compute_precache_lut(output, inverted, inverted_size); + free(inverted); + } else { + if (trc->count == 0) { + compute_precache_linear(output); + } else if (trc->count == 1) { + compute_precache_pow(output, 1./u8Fixed8Number_to_float(trc->data[0])); + } else { + uint16_t *inverted; + int inverted_size = trc->count; + //XXX: the choice of a minimum of 256 here is not backed by any theory, + // measurement or data, howeve r it is what lcms uses. + // the maximum number we would need is 65535 because that's the + // accuracy used for computing the pre cache table + if (inverted_size < 256) + inverted_size = 256; + + inverted = invert_lut(trc->data, trc->count, inverted_size); + if (!inverted) + return false; + compute_precache_lut(output, inverted, inverted_size); + free(inverted); + } + } + return true; +} + + +static uint16_t *build_linear_table(int length) +{ + int i; + uint16_t *output = malloc(sizeof(uint16_t)*length); + if (!output) + return NULL; + + for (i = 0; i < length; i++) { + double x = ((double) i * 65535.) / (double) (length - 1); + uint16_fract_t input = floor(x + .5); + output[i] = input; + } + return output; +} + +static uint16_t *build_pow_table(float gamma, int length) +{ + int i; + uint16_t *output = malloc(sizeof(uint16_t)*length); + if (!output) + return NULL; + + for (i = 0; i < length; i++) { + uint16_fract_t result; + double x = ((double) i) / (double) (length - 1); + x = pow(x, gamma); //XXX turn this conversion into a function + result = floor(x*65535. + .5); + output[i] = result; + } + return output; +} + +void build_output_lut(struct curveType *trc, + uint16_t **output_gamma_lut, size_t *output_gamma_lut_length) +{ + if (trc->type == PARAMETRIC_CURVE_TYPE) { + float gamma_table[256]; + uint16_t i; + uint16_t *output = malloc(sizeof(uint16_t)*256); + + if (!output) { + *output_gamma_lut = NULL; + return; + } + + compute_curve_gamma_table_type_parametric(gamma_table, trc->parameter, trc->count); + *output_gamma_lut_length = 256; + for(i = 0; i < 256; i++) { + output[i] = (uint16_t)(gamma_table[i] * 65535); + } + *output_gamma_lut = output; + } else { + if (trc->count == 0) { + *output_gamma_lut = build_linear_table(4096); + *output_gamma_lut_length = 4096; + } else if (trc->count == 1) { + float gamma = 1./u8Fixed8Number_to_float(trc->data[0]); + *output_gamma_lut = build_pow_table(gamma, 4096); + *output_gamma_lut_length = 4096; + } else { + //XXX: the choice of a minimum of 256 here is not backed by any theory, + // measurement or data, however it is what lcms uses. + *output_gamma_lut_length = trc->count; + if (*output_gamma_lut_length < 256) + *output_gamma_lut_length = 256; + + *output_gamma_lut = invert_lut(trc->data, trc->count, *output_gamma_lut_length); + } + } + +} + |