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tonemapper: simple implementation of the bloom filter from 'Physically-Based Glare Effects for Digital Images'

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Wenzel Jakob 2013-10-26 01:25:23 +02:00
parent 1ca3ca5a2f
commit 76260c731d
1 changed files with 97 additions and 10 deletions
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107
src/utils/tonemap.cpp
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@ -51,21 +51,64 @@ public:
cout << " -f fmt Request a certain output format (png/jpg, default:png)" << endl << endl;
cout << " -a Require the output image to have an alpha channel" << endl << endl;
cout << " -p key,burn Run Reinhard et al.'s photographic tonemapping operator. 'key'" << endl;
cout << " between [0, 1] chooses between low and high-key images and" << endl
<< " 'burn' (also [0, 1]) controls how much highlights may burn out" << endl << endl;
cout << " -x Temporal coherence mode: activate this flag when tonemapping " << endl
<< " frames of an animation using the '-p' option to avoid flicker" << endl << endl;
cout << " between [0, 1] chooses between low and high-key images and" << endl;
cout << " 'burn' (also [0, 1]) controls how much highlights may burn out" << endl << endl;
cout << " -B fov Apply a bloom filter that simulates scattering in the human" << endl;
cout << " eye. Requires the approx. field of view of the images to be" << endl;
cout << " processed in order to compute a point spread function." << endl << endl;
cout << " -x Temporal coherence mode: activate this flag when tonemapping " << endl;
cout << " frames of an animation using the '-p' option to avoid flicker" << endl << endl;
cout << " -o file Save the output with a given filename" << endl << endl;
cout << " -t Multithreaded: process several files in parallel" << endl << endl;
cout << " The operations are ordered as follows: 1. crop, 2. resize, 3. color-balance, " << endl;
cout << " 4. tonemap, 5. annotate. To simply process a directory full of EXRs in " << endl;
cout << " parallel, run the following: 'mtsutil tonemap -t path-to-directory/*.exr'" << endl;
cout << " The operations are ordered as follows: 1. crop, 2. bloom, 3. resize, 4. color" << endl;
cout << " balance, 5. tonemap, 6. annotate. To simply process a directory full of EXRs" << endl;
cout << " in parallel, run the following: 'mtsutil tonemap -t path-to-directory/*.exr'" << endl;
}
typedef struct {
int r[5];
} Rect;
/**
* Computes a bloom filter based on
*
* "Physically-Based Glare Effects for Digital Images" by
* Greg Spencer, Peter Shirley, Kurt Zimmerman and Donald P. Greenberg
* SIGGRAPH 1995
*/
ref<Bitmap> computeBloomFilter(int size, Float fov) {
ref<Bitmap> bitmap = new Bitmap(Bitmap::ELuminance, Bitmap::EFloat, Vector2i(size));
Float scale = 2.f / (size - 1),
halfLength = std::tan(.5f * degToRad(fov));
Float *ptr = bitmap->getFloatData();
double sum = 0;
for (int y=0; y<size; ++y) {
for (int x=0; x<size; ++x) {
Float xf = x*scale - 1,
yf = y*scale - 1,
r = std::sqrt(xf*xf+yf*yf),
angle = radToDeg(std::atan(r * halfLength)),
tmp = angle + 0.02f,
f0 = 2.61e6f * math::fastexp(-2500*angle*angle),
f1 = 20.91 / (tmp*tmp*tmp),
f2 = 72.37 / (tmp*tmp),
f = 0.384f*f0 + 0.478*f1 + 0.138*f2;
*ptr++ = f;
sum += f;
}
}
ptr = bitmap->getFloatData();
Float normalization = (Float) (1/sum);
for (int i=0; i<size*size; ++i)
*ptr++ *= normalization;
return bitmap;
}
int run(int argc, char **argv) {
ref<FileResolver> fileResolver = Thread::getThread()->getFileResolver();
int optchar;
@ -84,9 +127,10 @@ public:
Float logAvgLuminance = 0, maxLuminance = 0;
bool runParallel = false;
ReconstructionFilter *rfilter = NULL;
Float bloomFov = 0;
/* Parse command-line arguments */
while ((optchar = getopt(argc, argv, "htxag:m:f:r:b:c:o:p:s:")) != -1) {
while ((optchar = getopt(argc, argv, "htxag:m:f:r:b:c:o:p:s:B:")) != -1) {
switch (optchar) {
case 'h': {
help();
@ -115,6 +159,17 @@ public:
}
break;
case 'B':
bloomFov = (Float) strtod(optarg, &end_ptr);
#if !defined(MTS_HAS_FFTW)
Log(EWarn, "Applying a bloom filter without FFTW support compiled into "
"Mitsuba is likely going to be very, very slow!");
#endif
if (*end_ptr != '\0')
SLog(EError, "Could not parse the bloom field of view!");
break;
case 'm':
multiplier = (Float) strtod(optarg, &end_ptr);
if (*end_ptr != '\0')
@ -199,6 +254,9 @@ public:
}
}
if (bloomFov != 0 && (bloomFov <= 0 || bloomFov >= 180))
Log(EError, "Bloom field of view value must be between 0 and 180!");
if (runParallel) {
if (outputFilename != "" || temporalCoherence) {
Log(EWarn, "Requested multithreaded tonemapping along with incompatible options, disabling threading..");
@ -244,6 +302,20 @@ public:
if (crop[2] != -1 && crop[3] != -1)
input = input->crop(Point2i(crop[0], crop[1]), Vector2i(crop[2], crop[3]));
if (bloomFov != 0) {
int maxDim = std::max(input->getWidth(), input->getHeight());
if (maxDim % 1 == 0)
++maxDim;
ref<Bitmap> bloomFilter = computeBloomFilter(maxDim, bloomFov);
if (input->getComponentFormat() != Bitmap::EFloat)
input = input->convert(input->getPixelFormat(), Bitmap::EFloat);
Log(EInfo, "Convolving image with bloom filter ..");
input->convolve(bloomFilter);
}
if (resize[0] != -1)
input = input->resample(rfilter, ReconstructionFilter::EClamp,
ReconstructionFilter::EClamp, Vector2i(resize[0], resize[1]));
@ -278,8 +350,8 @@ public:
ref<FileStream> os = new FileStream(outputFile, FileStream::ETruncReadWrite);
output->write(format, os);
}
} else {
ref<Bitmap> bloomFilter;
for (int i=optind; i<argc; ++i) {
fs::path inputFile = fileResolver->resolve(argv[i]);
Log(EInfo, "Loading image \"%s\" ..", inputFile.string().c_str());
@ -289,9 +361,24 @@ public:
if (crop[2] != -1 && crop[3] != -1)
input = input->crop(Point2i(crop[0], crop[1]), Vector2i(crop[2], crop[3]));
if (bloomFov != 0) {
int maxDim = std::max(input->getWidth(), input->getHeight());
if (maxDim % 1 == 0)
++maxDim;
if (bloomFilter == NULL || bloomFilter->getWidth() != maxDim)
bloomFilter = computeBloomFilter(maxDim, bloomFov);
if (input->getComponentFormat() != Bitmap::EFloat)
input = input->convert(input->getPixelFormat(), Bitmap::EFloat);
Log(EInfo, "Convolving image with bloom filter ..");
input->convolve(bloomFilter);
}
if (resize[0] != -1)
input = input->resample(rfilter, ReconstructionFilter::EClamp,
ReconstructionFilter::EClamp, Vector2i(resize[0], resize[1]));
ReconstructionFilter::EClamp, Vector2i(resize[0], resize[1]));
if (cbal[0] != 1 || cbal[1] != 1 || cbal[2] != 1)
input->colorBalance(cbal[0], cbal[1], cbal[2]);