mitsuba/src/films/ldrfilm.cpp

407 lines
15 KiB
C++

/*
This file is part of Mitsuba, a physically based rendering system.
Copyright (c) 2007-2012 by Wenzel Jakob and others.
Mitsuba is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License Version 3
as published by the Free Software Foundation.
Mitsuba is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <mitsuba/render/film.h>
#include <mitsuba/core/fstream.h>
#include <mitsuba/core/bitmap.h>
#include <mitsuba/core/statistics.h>
#include <boost/algorithm/string.hpp>
#include "banner.h"
#include "annotations.h"
MTS_NAMESPACE_BEGIN
/*!\plugin{ldrfilm}{Low dynamic range film}
* \order{3}
* \parameters{
* \parameter{width, height}{\Integer}{
* Camera sensor resolution in pixels
* \default{768, 576}
* }
* \parameter{fileFormat}{\Integer}{
* The desired output file format:
* \code{png} or \code{jpeg}. \default{\code{png}}
* }
* \parameter{pixelFormat}{\String}{Specifies the pixel format
* of the generated image. The options are \code{luminance},
* \code{luminanceAlpha}, \code{rgb} or \code{rgba} for PNG output
* and \code{rgb} or \code{luminance} for JPEG output.
* }
* \parameter{tonemapMethod}{\String}{
* Method used to tonemap recorded radiance values
* \vspace{-2mm}
* \begin{enumerate}[(i)]
* \item \code{gamma}: Exposure and gamma correction (default)
* \vspace{-1mm}
* \item \code{reinhard}: Apply the the
* tonemapping technique by Reinhard et al. \cite{Reinhard2002Photographic}
* followd by gamma correction.
* \vspace{-4mm}
* \end{enumerate}
* }
* \parameter{gamma}{\Float}{
* The gamma curve applied to correct the output image,
* where the special value -1 indicates sRGB. \default{-1}
* }
* \parameter{exposure}{\Float}{
* When \code{gamma} tonemapping is active, this parameter specifies
* an exposure factor in f-stops that is applied to the image before
* gamma correction (scaling the radiance values by $2^{\,\text{exposure}}$).
* \default{0, i.e. do not change the exposure}
* }
* \parameter{key}{\Float}{
* When \code{reinhard} tonemapping is active, this parameter in $(0,1]$ specifies
* whether a low-key or high-key image is desired.
* \default{0.18, corresponding to a middle-grey}
* }
* \parameter{burn}{\Float}{
* When \code{reinhard} tonemapping is active, this parameter in $[0,1]$ specifies how much
* highlights can burn out. \default{0, i.e. map all luminance values into the displayable range}
* }
* \parameter{banner}{\Boolean}{Include a banner in the
* output image?\default{\code{true}}
* }
* \parameter{cropOffsetX, cropOffsetY, cropWidth, cropHeight}{\Integer}{
* These parameters can optionally be provided to select a sub-rectangle
* of the output. In this case, Mitsuba will only render the requested
* regions. \default{Unused}
* }
* \parameter{highQualityEdges}{\Boolean}{
* If set to \code{true}, regions slightly outside of the film
* plane will also be sampled. This may improve image
* quality at the edges, but is not needed in general.
* \default{\code{false}}
* }
* \parameter{\Unnamed}{\RFilter}{Reconstruction filter that should
* be used by the film. \default{\code{gaussian}, a windowed Gaussian filter}}
* }
* This plugin implements a low dynamic range film that can write out 8-bit PNG
* and JPEG images in various configurations. It provides basic tonemapping techniques
* to map recorded radiance values into a reasonable displayable range. An alpha (opacity)
* channel can be written if desired. By default, the plugin writes gamma-corrected
* PNG files using the sRGB color space and no alpha channel.
*
* This film is a good choice when low dynamic range output is desired
* and the rendering setup can be configured to capture the relevant portion
* of the dynamic range reliably enough so that the original HDR data can safely
* be discarded. When this is not the case, it may be easier to use \pluginref{hdrfilm}
* along with the batch tonemapper (\secref{tonemapper}).
*
* By default, the plugin assumes that no special tonemapping needs to be done and simply
* applies an exposure multiplier and sRGB gamma curve to the recorded radiance values
* before converting them to 8 bit. When the dynamic range varies greatly, it may be
* preferable to use the photographic tonemapping technique by Reinhard et al.
* \cite{Reinhard2002Photographic}, which can be activated by setting \code{tonemapMethod=reinhard}.
*
* Note that the interactive tonemapper that is available in the graphical user interface \code{mtsgui}
* interoperates with this plugin. In particular, when saving the scene
* (\emph{File}$\to$\emph{Save}), the currently active tonemapper
* settings are automatically exported into the updated scene file.
*
* The RGB values exported by this plugin correspond to the ITU-R Rec. BT. 709-3
* primaries with a D65 white point. When $\texttt{gamma}$ is set to $\code{-1}$ (the default),
* the output is in the sRGB color space and will display as intended on compatible devices.
*
* Note that this plugin supports render-time \emph{annotations}, which
* are described on page~\pageref{sec:film-annotations}.
*/
class LDRFilm : public Film {
public:
enum ETonemapMethod {
EGamma,
EReinhard
};
LDRFilm(const Properties &props) : Film(props) {
/* Should an Mitsuba banner be added to the output image? */
m_hasBanner = props.getBoolean("banner", true);
std::string fileFormat = boost::to_lower_copy(
props.getString("fileFormat", "png"));
std::string pixelFormat = boost::to_lower_copy(
props.getString("pixelFormat", "rgb"));
std::string tonemapMethod = boost::to_lower_copy(
props.getString("tonemapMethod", "gamma"));
if (fileFormat == "png") {
m_fileFormat = Bitmap::EPNG;
} else if (fileFormat == "jpg" || fileFormat == "jpeg") {
m_fileFormat = Bitmap::EJPEG;
} else {
Log(EError, "The \"fileFormat\" parameter must either be equal to "
"\"png\" or \"jpeg\"!");
}
if (tonemapMethod == "gamma") {
m_tonemapMethod = EGamma;
} else if (tonemapMethod == "reinhard") {
m_tonemapMethod = EReinhard;
} else {
Log(EError, "The \"method\" parameter must either be equal to "
"\"gamma\" or \"reinhard\"!");
}
if (pixelFormat == "luminance") {
m_pixelFormat = Bitmap::ELuminance;
} else if (pixelFormat == "luminancealpha") {
m_pixelFormat = Bitmap::ELuminanceAlpha;
} else if (pixelFormat == "rgb") {
m_pixelFormat = Bitmap::ERGB;
} else if (pixelFormat == "rgba") {
m_pixelFormat = Bitmap::ERGBA;
} else {
Log(EError, "The \"pixelFormat\" parameter must either be equal to "
"\"luminance\", \"luminanceAlpha\", \"rgb\", or \"rgba\"!");
}
if (m_pixelFormat == Bitmap::ELuminanceAlpha && m_fileFormat == Bitmap::EJPEG) {
Log(EWarn, "Ignoring request to write an alpha channel, since the JPEG format does not support it.");
m_pixelFormat = Bitmap::ELuminance;
} else if (m_pixelFormat == Bitmap::ERGBA && m_fileFormat == Bitmap::EJPEG) {
Log(EWarn, "Ignoring request to write an alpha channel, since the JPEG format does not support it.");
m_pixelFormat = Bitmap::ERGB;
}
m_gamma = props.getFloat("gamma", -1);
m_exposure = props.getFloat("exposure", 0.0f);
m_reinhardKey = props.getFloat("key", 0.18f);
m_reinhardBurn = props.getFloat("burn", 0.0);
std::vector<std::string> keys = props.getPropertyNames();
for (size_t i=0; i<keys.size(); ++i) {
std::string key = boost::to_lower_copy(keys[i]);
key.erase(std::remove_if(key.begin(), key.end(), ::isspace), key.end());
if ((boost::starts_with(key, "tag('") && boost::ends_with(key, "')")) ||
(boost::starts_with(key, "text(") && boost::ends_with(key, ")")))
props.markQueried(keys[i]);
}
m_storage = new ImageBlock(Bitmap::ESpectrumAlphaWeight, m_cropSize);
}
LDRFilm(Stream *stream, InstanceManager *manager)
: Film(stream, manager) {
m_hasBanner = stream->readBool();
m_pixelFormat = (Bitmap::EPixelFormat) stream->readUInt();
m_fileFormat = (Bitmap::EFileFormat) stream->readUInt();
m_gamma = stream->readFloat();
m_tonemapMethod = (ETonemapMethod) stream->readUInt();
m_exposure = stream->readFloat();
m_reinhardKey = stream->readFloat();
m_reinhardBurn = stream->readFloat();
}
void serialize(Stream *stream, InstanceManager *manager) const {
Film::serialize(stream, manager);
stream->writeBool(m_hasBanner);
stream->writeUInt(m_fileFormat);
stream->writeUInt(m_pixelFormat);
stream->writeFloat(m_gamma);
stream->writeUInt(m_tonemapMethod);
stream->writeFloat(m_exposure);
stream->writeFloat(m_reinhardKey);
stream->writeFloat(m_reinhardBurn);
}
void clear() {
m_storage->clear();
}
void put(const ImageBlock *block) {
m_storage->put(block);
}
void setBitmap(const Bitmap *bitmap, Float multiplier) {
bitmap->convert(m_storage->getBitmap(), multiplier);
}
void addBitmap(const Bitmap *bitmap, Float multiplier) {
/* Currently, only accumulating spectrum-valued floating point images
is supported. This function basically just exists to support the
somewhat peculiar film updates done by BDPT */
Vector2i size = bitmap->getSize();
if (bitmap->getPixelFormat() != Bitmap::ESpectrum ||
bitmap->getComponentFormat() != Bitmap::EFloat ||
bitmap->getGamma() != 1.0f ||
size != m_storage->getSize()) {
Log(EError, "addBitmap(): Unsupported bitmap format!");
}
size_t nPixels = (size_t) size.x * (size_t) size.y;
const Float *source = bitmap->getFloatData();
Float *target = m_storage->getBitmap()->getFloatData();
for (size_t i=0; i<nPixels; ++i) {
Float weight = target[SPECTRUM_SAMPLES + 1];
if (weight == 0)
weight = target[SPECTRUM_SAMPLES + 1] = 1;
weight *= multiplier;
for (size_t j=0; j<SPECTRUM_SAMPLES; ++j)
*target++ += *source++ * weight;
target += 2;
}
}
bool develop(const Point2i &sourceOffset, const Vector2i &size,
const Point2i &targetOffset, Bitmap *target) const {
const Bitmap *source = m_storage->getBitmap();
const FormatConverter *cvt = FormatConverter::getInstance(
std::make_pair(Bitmap::EFloat, target->getComponentFormat())
);
size_t sourceBpp = source->getBytesPerPixel();
size_t targetBpp = target->getBytesPerPixel();
const uint8_t *sourceData = source->getUInt8Data()
+ (sourceOffset.x + sourceOffset.y * source->getWidth()) * sourceBpp;
uint8_t *targetData = target->getUInt8Data()
+ (targetOffset.x + targetOffset.y * target->getWidth()) * targetBpp;
if (size.x == m_cropSize.x) {
/* Develop a connected part of the underlying buffer */
cvt->convert(source->getPixelFormat(), 1.0f, sourceData,
target->getPixelFormat(), target->getGamma(), targetData,
size.x*size.y);
} else {
/* Develop a rectangular subregion */
for (int i=0; i<size.y; ++i) {
cvt->convert(source->getPixelFormat(), 1.0f, sourceData,
target->getPixelFormat(), target->getGamma(), targetData,
size.x);
sourceData += source->getWidth() * sourceBpp;
targetData += target->getWidth() * targetBpp;
}
}
return true;
}
void setDestinationFile(const fs::path &destFile, uint32_t blockSize) {
m_destFile = destFile;
}
void develop(const Scene *scene, Float renderTime) {
Log(EDebug, "Developing film ..");
ref<Bitmap> bitmap = m_storage->getBitmap();
Float multiplier = 1.0f;
if (m_tonemapMethod == EReinhard) {
bitmap = bitmap->convert(m_pixelFormat, Bitmap::EFloat);
Float logAvgLuminance = 0, maxLuminance = 0; /* Unused */
bitmap->tonemapReinhard(logAvgLuminance, maxLuminance,
m_reinhardKey, m_reinhardBurn);
Log(EInfo, "Tonemapping finished (log-avg luminance=%f, max luminance=%f)",
logAvgLuminance, maxLuminance);
} else {
multiplier = std::pow((Float) 2, (Float) m_exposure);
}
bitmap = bitmap->convert(m_pixelFormat, Bitmap::EUInt8, m_gamma, multiplier);
if (m_hasBanner && m_cropSize.x > bannerWidth+5 && m_cropSize.y > bannerHeight + 5) {
int xoffs = m_cropSize.x - bannerWidth - 5,
yoffs = m_cropSize.y - bannerHeight - 5;
for (int y=0; y<bannerHeight; y++) {
for (int x=0; x<bannerWidth; x++) {
if (banner[x+y*bannerWidth])
continue;
bitmap->setPixel(Point2i(x+xoffs, y+yoffs), Spectrum(1));
}
}
}
fs::path filename = m_destFile;
std::string extension = boost::to_lower_copy(filename.extension().string());
std::string expectedExtension;
switch (m_fileFormat) {
case Bitmap::EPNG: expectedExtension = ".png"; break;
case Bitmap::EJPEG: expectedExtension = ".jpg"; break;
default:
Log(EError, "Unknown file format!");
}
if (extension != expectedExtension)
filename.replace_extension(expectedExtension);
Log(EInfo, "Writing image to \"%s\" ..", filename.string().c_str());
ref<FileStream> stream = new FileStream(filename, FileStream::ETruncWrite);
annotate(scene, m_properties, bitmap, renderTime, m_gamma);
bitmap->write(m_fileFormat, stream);
}
bool hasAlpha() const {
return
m_pixelFormat == Bitmap::ELuminanceAlpha ||
m_pixelFormat == Bitmap::ERGBA;
}
bool destinationExists(const fs::path &baseName) const {
fs::path filename = baseName;
std::string extension;
switch (m_fileFormat) {
case Bitmap::EPNG: extension = ".png"; break;
case Bitmap::EJPEG: extension = ".jpg"; break;
default:
Log(EError, "Unknown file format!");
return false;
}
if (boost::to_lower_copy(filename.extension().string()) != extension)
filename.replace_extension(extension);
return fs::exists(filename);
}
std::string toString() const {
std::ostringstream oss;
oss << "LDRFilm[" << endl
<< " size = " << m_size.toString() << "," << endl
<< " fileFormat = " << m_fileFormat << "," << endl
<< " pixelFormat = " << m_pixelFormat << "," << endl
<< " gamma = " << m_gamma << "," << endl
<< " cropOffset = " << m_cropOffset.toString() << "," << endl
<< " cropSize = " << m_cropSize.toString() << "," << endl
<< " banner = " << m_hasBanner << "," << endl
<< " method = " << ((m_tonemapMethod == EGamma) ? "gamma" : "reinhard") << "," << endl
<< " exposure = " << m_exposure << "," << endl
<< " reinhardKey = " << m_reinhardKey << "," << endl
<< " reinhardBurn = " << m_reinhardBurn << "," << endl
<< " filter = " << indent(m_filter->toString()) << endl
<< "]";
return oss.str();
}
MTS_DECLARE_CLASS()
protected:
Bitmap::EFileFormat m_fileFormat;
Bitmap::EPixelFormat m_pixelFormat;
bool m_hasBanner;
fs::path m_destFile;
Float m_gamma;
ref<ImageBlock> m_storage;
ETonemapMethod m_tonemapMethod;
Float m_exposure, m_reinhardKey, m_reinhardBurn;
};
MTS_IMPLEMENT_CLASS_S(LDRFilm, false, Film)
MTS_EXPORT_PLUGIN(LDRFilm, "Low dynamic range film");
MTS_NAMESPACE_END