Files
test2/intern/opencolorio/fallback_impl.cc
Lukas Stockner 6967255906 Color management: Support white balance as part of the display transform
This implements a von-Kries-style chromatic adaption using the Bradford matrix.
The adaption is performed in scene linear space in the OCIO GLSL shader, with
the matrix being computed on the host.

The parameters specify the white point of the input, which is to be mapped to
the white point of the scene linear space. The main parameter is temperature,
specified in Kelvin, which defines the blackbody spectrum that is used as the
input white point. Additionally, a tint parameter can be used to shift the
white point away from pure blackbody spectra (e.g. to match a D illuminant).

The defaults are set to match D65 so there is no immediate color shift when
enabling the option. Tint = 10 is needed since the D-series illuminants aren't
perfect blackbody emitters.

As an alternative to manually specifying the values, there's also a color
picker. When a color is selected, temperature and tint are set such that this
color ends up being balanced to white.
This only works if the color is close enough to a blackbody emitter -
specifically, for tint values within +-150. Beyond this, there can be ambiguity
in the representation.
Currently, in this case, the input is just ignored and temperature/tint aren't
changed. Ideally, we'd eventually give UI feedback for this.

Presets are supported, and all the CIE standard illuminants are included.

One part that I'm not quite happy with is that the tint parameter starts to
give weird results at moderate values when the temperature is low.
The reason for this can be seen here:
https://commons.wikimedia.org/wiki/File:Planckian-locus.png
Tint is moving along the isotherm lines (with the plot corresponding to +-150),
but below 4000K some of that range is outside of the gamut. Not much can
be done there, other than possibly clipping those values...

Adding support for this to the compositor should be quite easy and is planned
as a next step.

Pull Request: https://projects.blender.org/blender/blender/pulls/123278
2024-06-27 23:27:58 +02:00

544 lines
15 KiB
C++

/* SPDX-FileCopyrightText: 2012 Blender Authors
*
* SPDX-License-Identifier: GPL-2.0-or-later */
#include <algorithm>
#include <cstring>
#include <vector>
#include "BLI_math_color.h"
#include "BLI_math_vector.h"
#include "MEM_guardedalloc.h"
#include "ocio_impl.h"
using std::max;
#define CONFIG_DEFAULT ((OCIO_ConstConfigRcPtr *)1)
enum TransformType {
TRANSFORM_LINEAR_TO_SRGB,
TRANSFORM_SRGB_TO_LINEAR,
TRANSFORM_SCALE,
TRANSFORM_EXPONENT,
TRANSFORM_NONE,
TRANSFORM_UNKNOWN,
};
#define COLORSPACE_LINEAR ((OCIO_ConstColorSpaceRcPtr *)1)
#define COLORSPACE_SRGB ((OCIO_ConstColorSpaceRcPtr *)2)
#define COLORSPACE_DATA ((OCIO_ConstColorSpaceRcPtr *)3)
struct OCIO_PackedImageDescription {
float *data;
long width;
long height;
long numChannels;
long chanStrideBytes;
long xStrideBytes;
long yStrideBytes;
};
struct FallbackTransform {
FallbackTransform() : type(TRANSFORM_UNKNOWN), scale(1.0f), exponent(1.0f) {}
virtual ~FallbackTransform() {}
void applyRGB(float *pixel)
{
if (type == TRANSFORM_LINEAR_TO_SRGB) {
pixel[0] *= scale;
pixel[1] *= scale;
pixel[2] *= scale;
linearrgb_to_srgb_v3_v3(pixel, pixel);
pixel[0] = powf(max(0.0f, pixel[0]), exponent);
pixel[1] = powf(max(0.0f, pixel[1]), exponent);
pixel[2] = powf(max(0.0f, pixel[2]), exponent);
}
else if (type == TRANSFORM_SRGB_TO_LINEAR) {
srgb_to_linearrgb_v3_v3(pixel, pixel);
}
else if (type == TRANSFORM_EXPONENT) {
pixel[0] = powf(max(0.0f, pixel[0]), exponent);
pixel[1] = powf(max(0.0f, pixel[1]), exponent);
pixel[2] = powf(max(0.0f, pixel[2]), exponent);
}
else if (type == TRANSFORM_SCALE) {
pixel[0] *= scale;
pixel[1] *= scale;
pixel[2] *= scale;
}
}
void applyRGBA(float *pixel)
{
applyRGB(pixel);
}
bool isNoOp()
{
/* Rely on the short-circuiting based on name-space comparison in the IMB_colormanagement. */
return false;
}
TransformType type;
/* Scale transform. */
float scale;
/* Exponent transform. */
float exponent;
MEM_CXX_CLASS_ALLOC_FUNCS("FallbackTransform");
};
struct FallbackProcessor {
FallbackProcessor(const FallbackTransform &transform) : transform(transform) {}
void applyRGB(float *pixel)
{
transform.applyRGB(pixel);
}
void applyRGBA(float *pixel)
{
transform.applyRGBA(pixel);
}
bool isNoOp()
{
return transform.isNoOp();
}
FallbackTransform transform;
MEM_CXX_CLASS_ALLOC_FUNCS("FallbackProcessor");
};
OCIO_ConstConfigRcPtr *FallbackImpl::getCurrentConfig()
{
return CONFIG_DEFAULT;
}
void FallbackImpl::setCurrentConfig(const OCIO_ConstConfigRcPtr * /*config*/) {}
OCIO_ConstConfigRcPtr *FallbackImpl::configCreateFromEnv()
{
return NULL;
}
OCIO_ConstConfigRcPtr *FallbackImpl::configCreateFromFile(const char * /*filename*/)
{
return CONFIG_DEFAULT;
}
void FallbackImpl::configRelease(OCIO_ConstConfigRcPtr * /*config*/) {}
int FallbackImpl::configGetNumColorSpaces(OCIO_ConstConfigRcPtr * /*config*/)
{
return 2;
}
const char *FallbackImpl::configGetColorSpaceNameByIndex(OCIO_ConstConfigRcPtr * /*config*/,
int index)
{
if (index == 0) {
return "Linear";
}
else if (index == 1) {
return "sRGB";
}
return NULL;
}
OCIO_ConstColorSpaceRcPtr *FallbackImpl::configGetColorSpace(OCIO_ConstConfigRcPtr * /*config*/,
const char *name)
{
if (strcmp(name, "scene_linear") == 0) {
return COLORSPACE_LINEAR;
}
else if (strcmp(name, "color_picking") == 0) {
return COLORSPACE_SRGB;
}
else if (strcmp(name, "texture_paint") == 0) {
return COLORSPACE_LINEAR;
}
else if (strcmp(name, "default_byte") == 0) {
return COLORSPACE_SRGB;
}
else if (strcmp(name, "default_float") == 0) {
return COLORSPACE_LINEAR;
}
else if (strcmp(name, "default_sequencer") == 0) {
return COLORSPACE_SRGB;
}
else if (strcmp(name, "Linear") == 0) {
return COLORSPACE_LINEAR;
}
else if (strcmp(name, "sRGB") == 0) {
return COLORSPACE_SRGB;
}
else if (strcmp(name, "data") == 0) {
return COLORSPACE_DATA;
}
return NULL;
}
int FallbackImpl::configGetIndexForColorSpace(OCIO_ConstConfigRcPtr *config, const char *name)
{
OCIO_ConstColorSpaceRcPtr *cs = configGetColorSpace(config, name);
if (cs == COLORSPACE_LINEAR) {
return 0;
}
else if (cs == COLORSPACE_SRGB) {
return 1;
}
else if (cs == COLORSPACE_DATA) {
return 2;
}
return -1;
}
const char *FallbackImpl::configGetDefaultDisplay(OCIO_ConstConfigRcPtr * /*config*/)
{
return "sRGB";
}
int FallbackImpl::configGetNumDisplays(OCIO_ConstConfigRcPtr * /*config*/)
{
return 1;
}
const char *FallbackImpl::configGetDisplay(OCIO_ConstConfigRcPtr * /*config*/, int index)
{
if (index == 0) {
return "sRGB";
}
return NULL;
}
const char *FallbackImpl::configGetDefaultView(OCIO_ConstConfigRcPtr * /*config*/,
const char * /*display*/)
{
return "Standard";
}
int FallbackImpl::configGetNumViews(OCIO_ConstConfigRcPtr * /*config*/, const char * /*display*/)
{
return 1;
}
const char *FallbackImpl::configGetView(OCIO_ConstConfigRcPtr * /*config*/,
const char * /*display*/,
int index)
{
if (index == 0) {
return "Standard";
}
return NULL;
}
const char *FallbackImpl::configGetDisplayColorSpaceName(OCIO_ConstConfigRcPtr * /*config*/,
const char * /*display*/,
const char * /*view*/)
{
return "sRGB";
}
void FallbackImpl::configGetDefaultLumaCoefs(OCIO_ConstConfigRcPtr * /*config*/, float *rgb)
{
/* Here we simply use the older Blender assumed primaries of
* ITU-BT.709 / sRGB, or 0.2126729 0.7151522 0.0721750. Brute
* force stupid, but only plausible option given no color management
* system in place.
*/
rgb[0] = 0.2126f;
rgb[1] = 0.7152f;
rgb[2] = 0.0722f;
}
void FallbackImpl::configGetXYZtoSceneLinear(OCIO_ConstConfigRcPtr * /*config*/,
float xyz_to_scene_linear[3][3])
{
/* Default to ITU-BT.709. */
memcpy(xyz_to_scene_linear, OCIO_XYZ_TO_REC709, sizeof(OCIO_XYZ_TO_REC709));
}
int FallbackImpl::configGetNumLooks(OCIO_ConstConfigRcPtr * /*config*/)
{
return 0;
}
const char *FallbackImpl::configGetLookNameByIndex(OCIO_ConstConfigRcPtr * /*config*/,
int /*index*/)
{
return "";
}
OCIO_ConstLookRcPtr *FallbackImpl::configGetLook(OCIO_ConstConfigRcPtr * /*config*/,
const char * /*name*/)
{
return NULL;
}
const char *FallbackImpl::lookGetProcessSpace(OCIO_ConstLookRcPtr * /*look*/)
{
return NULL;
}
void FallbackImpl::lookRelease(OCIO_ConstLookRcPtr * /*look*/) {}
int FallbackImpl::colorSpaceIsInvertible(OCIO_ConstColorSpaceRcPtr * /*cs*/)
{
return 1;
}
int FallbackImpl::colorSpaceIsData(OCIO_ConstColorSpaceRcPtr * /*cs*/)
{
return 0;
}
void FallbackImpl::colorSpaceIsBuiltin(OCIO_ConstConfigRcPtr * /*config*/,
OCIO_ConstColorSpaceRcPtr *cs,
bool &is_scene_linear,
bool &is_srgb)
{
if (cs == COLORSPACE_LINEAR) {
is_scene_linear = true;
is_srgb = false;
}
else if (cs == COLORSPACE_SRGB) {
is_scene_linear = false;
is_srgb = true;
}
else {
is_scene_linear = false;
is_srgb = false;
}
}
void FallbackImpl::colorSpaceRelease(OCIO_ConstColorSpaceRcPtr * /*cs*/) {}
OCIO_ConstProcessorRcPtr *FallbackImpl::configGetProcessorWithNames(OCIO_ConstConfigRcPtr *config,
const char *srcName,
const char *dstName)
{
OCIO_ConstColorSpaceRcPtr *cs_src = configGetColorSpace(config, srcName);
OCIO_ConstColorSpaceRcPtr *cs_dst = configGetColorSpace(config, dstName);
FallbackTransform transform;
if (cs_src == COLORSPACE_DATA || cs_dst == COLORSPACE_DATA) {
transform.type = TRANSFORM_NONE;
}
else if (cs_src == COLORSPACE_LINEAR && cs_dst == COLORSPACE_SRGB) {
transform.type = TRANSFORM_LINEAR_TO_SRGB;
}
else if (cs_src == COLORSPACE_SRGB && cs_dst == COLORSPACE_LINEAR) {
transform.type = TRANSFORM_SRGB_TO_LINEAR;
}
else {
transform.type = TRANSFORM_UNKNOWN;
}
return (OCIO_ConstProcessorRcPtr *)new FallbackProcessor(transform);
}
OCIO_ConstCPUProcessorRcPtr *FallbackImpl::processorGetCPUProcessor(
OCIO_ConstProcessorRcPtr *processor)
{
/* Just make a copy of the processor so that we are compatible with OCIO
* which does need it as a separate object. */
FallbackProcessor *fallback_processor = (FallbackProcessor *)processor;
return (OCIO_ConstCPUProcessorRcPtr *)new FallbackProcessor(*fallback_processor);
}
void FallbackImpl::processorRelease(OCIO_ConstProcessorRcPtr *processor)
{
delete (FallbackProcessor *)(processor);
}
bool FallbackImpl::cpuProcessorIsNoOp(OCIO_ConstCPUProcessorRcPtr *cpu_processor)
{
return ((FallbackProcessor *)cpu_processor)->isNoOp();
}
void FallbackImpl::cpuProcessorApply(OCIO_ConstCPUProcessorRcPtr *cpu_processor,
OCIO_PackedImageDesc *img)
{
/* OCIO_TODO stride not respected, channels must be 3 or 4 */
OCIO_PackedImageDescription *desc = (OCIO_PackedImageDescription *)img;
int channels = desc->numChannels;
float *pixels = desc->data;
int width = desc->width;
int height = desc->height;
int x, y;
for (y = 0; y < height; y++) {
for (x = 0; x < width; x++) {
float *pixel = pixels + channels * (y * width + x);
if (channels == 4) {
cpuProcessorApplyRGBA(cpu_processor, pixel);
}
else if (channels == 3) {
cpuProcessorApplyRGB(cpu_processor, pixel);
}
}
}
}
void FallbackImpl::cpuProcessorApply_predivide(OCIO_ConstCPUProcessorRcPtr *cpu_processor,
OCIO_PackedImageDesc *img)
{
/* OCIO_TODO stride not respected, channels must be 3 or 4 */
OCIO_PackedImageDescription *desc = (OCIO_PackedImageDescription *)img;
int channels = desc->numChannels;
float *pixels = desc->data;
int width = desc->width;
int height = desc->height;
int x, y;
for (y = 0; y < height; y++) {
for (x = 0; x < width; x++) {
float *pixel = pixels + channels * (y * width + x);
if (channels == 4) {
cpuProcessorApplyRGBA_predivide(cpu_processor, pixel);
}
else if (channels == 3) {
cpuProcessorApplyRGB(cpu_processor, pixel);
}
}
}
}
void FallbackImpl::cpuProcessorApplyRGB(OCIO_ConstCPUProcessorRcPtr *cpu_processor, float *pixel)
{
((FallbackProcessor *)cpu_processor)->applyRGB(pixel);
}
void FallbackImpl::cpuProcessorApplyRGBA(OCIO_ConstCPUProcessorRcPtr *cpu_processor, float *pixel)
{
((FallbackProcessor *)cpu_processor)->applyRGBA(pixel);
}
void FallbackImpl::cpuProcessorApplyRGBA_predivide(OCIO_ConstCPUProcessorRcPtr *cpu_processor,
float *pixel)
{
if (pixel[3] == 1.0f || pixel[3] == 0.0f) {
cpuProcessorApplyRGBA(cpu_processor, pixel);
}
else {
float alpha, inv_alpha;
alpha = pixel[3];
inv_alpha = 1.0f / alpha;
pixel[0] *= inv_alpha;
pixel[1] *= inv_alpha;
pixel[2] *= inv_alpha;
cpuProcessorApplyRGBA(cpu_processor, pixel);
pixel[0] *= alpha;
pixel[1] *= alpha;
pixel[2] *= alpha;
}
}
void FallbackImpl::cpuProcessorRelease(OCIO_ConstCPUProcessorRcPtr *cpu_processor)
{
delete (FallbackProcessor *)(cpu_processor);
}
const char *FallbackImpl::colorSpaceGetName(OCIO_ConstColorSpaceRcPtr *cs)
{
if (cs == COLORSPACE_LINEAR) {
return "Linear";
}
else if (cs == COLORSPACE_SRGB) {
return "sRGB";
}
else if (cs == COLORSPACE_DATA) {
return "data";
}
return NULL;
}
const char *FallbackImpl::colorSpaceGetDescription(OCIO_ConstColorSpaceRcPtr * /*cs*/)
{
return "";
}
const char *FallbackImpl::colorSpaceGetFamily(OCIO_ConstColorSpaceRcPtr * /*cs*/)
{
return "";
}
int FallbackImpl::colorSpaceGetNumAliases(OCIO_ConstColorSpaceRcPtr * /*cs*/)
{
return 0;
}
const char *FallbackImpl::colorSpaceGetAlias(OCIO_ConstColorSpaceRcPtr * /*cs*/,
const int /*index*/)
{
return "";
}
OCIO_ConstProcessorRcPtr *FallbackImpl::createDisplayProcessor(OCIO_ConstConfigRcPtr * /*config*/,
const char * /*input*/,
const char * /*view*/,
const char * /*display*/,
const char * /*look*/,
const float scale,
const float exponent,
const float /*temperature*/,
const float /*tint*/,
const bool /*use_white_balance*/,
const bool inverse)
{
FallbackTransform transform;
transform.type = (inverse) ? TRANSFORM_SRGB_TO_LINEAR : TRANSFORM_LINEAR_TO_SRGB;
transform.scale = (inverse && scale != 0.0f) ? 1.0f / scale : scale;
transform.exponent = (inverse && exponent != 0.0f) ? 1.0f / exponent : exponent;
return (OCIO_ConstProcessorRcPtr *)new FallbackProcessor(transform);
}
OCIO_PackedImageDesc *FallbackImpl::createOCIO_PackedImageDesc(float *data,
long width,
long height,
long numChannels,
long chanStrideBytes,
long xStrideBytes,
long yStrideBytes)
{
OCIO_PackedImageDescription *desc = MEM_cnew<OCIO_PackedImageDescription>(
"OCIO_PackedImageDescription");
desc->data = data;
desc->width = width;
desc->height = height;
desc->numChannels = numChannels;
desc->chanStrideBytes = chanStrideBytes;
desc->xStrideBytes = xStrideBytes;
desc->yStrideBytes = yStrideBytes;
return (OCIO_PackedImageDesc *)desc;
}
void FallbackImpl::OCIO_PackedImageDescRelease(OCIO_PackedImageDesc *id)
{
MEM_freeN(id);
}
const char *FallbackImpl::getVersionString()
{
return "fallback";
}
int FallbackImpl::getVersionHex()
{
return 0;
}