//////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2004, Industrial Light & Magic, a division of Lucasfilm
// Entertainment Company Ltd. Portions contributed and copyright held by
// others as indicated. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above
// copyright notice, this list of conditions and the following
// disclaimer.
//
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided with
// the distribution.
//
// * Neither the name of Industrial Light & Magic nor the names of
// any other contributors to this software may be used to endorse or
// promote products derived from this software without specific prior
// written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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//
//////////////////////////////////////////////////////////////////////////////
//-----------------------------------------------------------------------------
//
// Conversion between RGBA and YCA data.
//
//-----------------------------------------------------------------------------
#include <ImfRgbaYca.h>
#include <assert.h>
#include <algorithm>
using namespace IMATH_NAMESPACE;
using namespace std;
#include "ImfNamespace.h"
OPENEXR_IMF_INTERNAL_NAMESPACE_SOURCE_ENTER
namespace RgbaYca {
V3f
computeYw (const Chromaticities &cr)
{
M44f m = RGBtoXYZ (cr, 1);
return V3f (m[0][1], m[1][1], m[2][1]) / (m[0][1] + m[1][1] + m[2][1]);
}
void
RGBAtoYCA (const V3f &yw,
int n,
bool aIsValid,
const Rgba rgbaIn[/*n*/],
Rgba ycaOut[/*n*/])
{
for (int i = 0; i < n; ++i)
{
Rgba in = rgbaIn[i];
Rgba &out = ycaOut[i];
//
// Conversion to YCA and subsequent chroma subsampling
// work only if R, G and B are finite and non-negative.
//
if (!in.r.isFinite() || in.r < 0)
in.r = 0;
if (!in.g.isFinite() || in.g < 0)
in.g = 0;
if (!in.b.isFinite() || in.b < 0)
in.b = 0;
if (in.r == in.g && in.g == in.b)
{
//
// Special case -- R, G and B are equal. To avoid rounding
// errors, we explicitly set the output luminance channel
// to G, and the chroma channels to 0.
//
// The special cases here and in YCAtoRGBA() ensure that
// converting black-and white images from RGBA to YCA and
// back is lossless.
//
out.r = 0;
out.g = in.g;
out.b = 0;
}
else
{
out.g = in.r * yw.x + in.g * yw.y + in.b * yw.z;
float Y = out.g;
if (abs (in.r - Y) < HALF_MAX * Y)
out.r = (in.r - Y) / Y;
else
out.r = 0;
if (abs (in.b - Y) < HALF_MAX * Y)
out.b = (in.b - Y) / Y;
else
out.b = 0;
}
if (aIsValid)
out.a = in.a;
else
out.a = 1;
}
}
void
decimateChromaHoriz (int n,
const Rgba ycaIn[/*n+N-1*/],
Rgba ycaOut[/*n*/])
{
#ifdef DEBUG
assert (ycaIn != ycaOut);
#endif
int begin = N2;
int end = begin + n;
for (int i = begin, j = 0; i < end; ++i, ++j)
{
if ((j & 1) == 0)
{
ycaOut[j].r = ycaIn[i - 13].r * 0.001064f +
ycaIn[i - 11].r * -0.003771f +
ycaIn[i - 9].r * 0.009801f +
ycaIn[i - 7].r * -0.021586f +
ycaIn[i - 5].r * 0.043978f +
ycaIn[i - 3].r * -0.093067f +
ycaIn[i - 1].r * 0.313659f +
ycaIn[i ].r * 0.499846f +
ycaIn[i + 1].r * 0.313659f +
ycaIn[i + 3].r * -0.093067f +
ycaIn[i + 5].r * 0.043978f +
ycaIn[i + 7].r * -0.021586f +
ycaIn[i + 9].r * 0.009801f +
ycaIn[i + 11].r * -0.003771f +
ycaIn[i + 13].r * 0.001064f;
ycaOut[j].b = ycaIn[i - 13].b * 0.001064f +
ycaIn[i - 11].b * -0.003771f +
ycaIn[i - 9].b * 0.009801f +
ycaIn[i - 7].b * -0.021586f +
ycaIn[i - 5].b * 0.043978f +
ycaIn[i - 3].b * -0.093067f +
ycaIn[i - 1].b * 0.313659f +
ycaIn[i ].b * 0.499846f +
ycaIn[i + 1].b * 0.313659f +
ycaIn[i + 3].b * -0.093067f +
ycaIn[i + 5].b * 0.043978f +
ycaIn[i + 7].b * -0.021586f +
ycaIn[i + 9].b * 0.009801f +
ycaIn[i + 11].b * -0.003771f +
ycaIn[i + 13].b * 0.001064f;
}
ycaOut[j].g = ycaIn[i].g;
ycaOut[j].a = ycaIn[i].a;
}
}
void
decimateChromaVert (int n,
const Rgba * const ycaIn[N],
Rgba ycaOut[/*n*/])
{
for (int i = 0; i < n; ++i)
{
if ((i & 1) == 0)
{
ycaOut[i].r = ycaIn[ 0][i].r * 0.001064f +
ycaIn[ 2][i].r * -0.003771f +
ycaIn[ 4][i].r * 0.009801f +
ycaIn[ 6][i].r * -0.021586f +
ycaIn[ 8][i].r * 0.043978f +
ycaIn[10][i].r * -0.093067f +
ycaIn[12][i].r * 0.313659f +
ycaIn[13][i].r * 0.499846f +
ycaIn[14][i].r * 0.313659f +
ycaIn[16][i].r * -0.093067f +
ycaIn[18][i].r * 0.043978f +
ycaIn[20][i].r * -0.021586f +
ycaIn[22][i].r * 0.009801f +
ycaIn[24][i].r * -0.003771f +
ycaIn[26][i].r * 0.001064f;
ycaOut[i].b = ycaIn[ 0][i].b * 0.001064f +
ycaIn[ 2][i].b * -0.003771f +
ycaIn[ 4][i].b * 0.009801f +
ycaIn[ 6][i].b * -0.021586f +
ycaIn[ 8][i].b * 0.043978f +
ycaIn[10][i].b * -0.093067f +
ycaIn[12][i].b * 0.313659f +
ycaIn[13][i].b * 0.499846f +
ycaIn[14][i].b * 0.313659f +
ycaIn[16][i].b * -0.093067f +
ycaIn[18][i].b * 0.043978f +
ycaIn[20][i].b * -0.021586f +
ycaIn[22][i].b * 0.009801f +
ycaIn[24][i].b * -0.003771f +
ycaIn[26][i].b * 0.001064f;
}
ycaOut[i].g = ycaIn[13][i].g;
ycaOut[i].a = ycaIn[13][i].a;
}
}
void
roundYCA (int n,
unsigned int roundY,
unsigned int roundC,
const Rgba ycaIn[/*n*/],
Rgba ycaOut[/*n*/])
{
for (int i = 0; i < n; ++i)
{
ycaOut[i].g = ycaIn[i].g.round (roundY);
ycaOut[i].a = ycaIn[i].a;
if ((i & 1) == 0)
{
ycaOut[i].r = ycaIn[i].r.round (roundC);
ycaOut[i].b = ycaIn[i].b.round (roundC);
}
}
}
void
reconstructChromaHoriz (int n,
const Rgba ycaIn[/*n+N-1*/],
Rgba ycaOut[/*n*/])
{
#ifdef DEBUG
assert (ycaIn != ycaOut);
#endif
int begin = N2;
int end = begin + n;
for (int i = begin, j = 0; i < end; ++i, ++j)
{
if (j & 1)
{
ycaOut[j].r = ycaIn[i - 13].r * 0.002128f +
ycaIn[i - 11].r * -0.007540f +
ycaIn[i - 9].r * 0.019597f +
ycaIn[i - 7].r * -0.043159f +
ycaIn[i - 5].r * 0.087929f +
ycaIn[i - 3].r * -0.186077f +
ycaIn[i - 1].r * 0.627123f +
ycaIn[i + 1].r * 0.627123f +
ycaIn[i + 3].r * -0.186077f +
ycaIn[i + 5].r * 0.087929f +
ycaIn[i + 7].r * -0.043159f +
ycaIn[i + 9].r * 0.019597f +
ycaIn[i + 11].r * -0.007540f +
ycaIn[i + 13].r * 0.002128f;
ycaOut[j].b = ycaIn[i - 13].b * 0.002128f +
ycaIn[i - 11].b * -0.007540f +
ycaIn[i - 9].b * 0.019597f +
ycaIn[i - 7].b * -0.043159f +
ycaIn[i - 5].b * 0.087929f +
ycaIn[i - 3].b * -0.186077f +
ycaIn[i - 1].b * 0.627123f +
ycaIn[i + 1].b * 0.627123f +
ycaIn[i + 3].b * -0.186077f +
ycaIn[i + 5].b * 0.087929f +
ycaIn[i + 7].b * -0.043159f +
ycaIn[i + 9].b * 0.019597f +
ycaIn[i + 11].b * -0.007540f +
ycaIn[i + 13].b * 0.002128f;
}
else
{
ycaOut[j].r = ycaIn[i].r;
ycaOut[j].b = ycaIn[i].b;
}
ycaOut[j].g = ycaIn[i].g;
ycaOut[j].a = ycaIn[i].a;
}
}
void
reconstructChromaVert (int n,
const Rgba * const ycaIn[N],
Rgba ycaOut[/*n*/])
{
for (int i = 0; i < n; ++i)
{
ycaOut[i].r = ycaIn[ 0][i].r * 0.002128f +
ycaIn[ 2][i].r * -0.007540f +
ycaIn[ 4][i].r * 0.019597f +
ycaIn[ 6][i].r * -0.043159f +
ycaIn[ 8][i].r * 0.087929f +
ycaIn[10][i].r * -0.186077f +
ycaIn[12][i].r * 0.627123f +
ycaIn[14][i].r * 0.627123f +
ycaIn[16][i].r * -0.186077f +
ycaIn[18][i].r * 0.087929f +
ycaIn[20][i].r * -0.043159f +
ycaIn[22][i].r * 0.019597f +
ycaIn[24][i].r * -0.007540f +
ycaIn[26][i].r * 0.002128f;
ycaOut[i].b = ycaIn[ 0][i].b * 0.002128f +
ycaIn[ 2][i].b * -0.007540f +
ycaIn[ 4][i].b * 0.019597f +
ycaIn[ 6][i].b * -0.043159f +
ycaIn[ 8][i].b * 0.087929f +
ycaIn[10][i].b * -0.186077f +
ycaIn[12][i].b * 0.627123f +
ycaIn[14][i].b * 0.627123f +
ycaIn[16][i].b * -0.186077f +
ycaIn[18][i].b * 0.087929f +
ycaIn[20][i].b * -0.043159f +
ycaIn[22][i].b * 0.019597f +
ycaIn[24][i].b * -0.007540f +
ycaIn[26][i].b * 0.002128f;
ycaOut[i].g = ycaIn[13][i].g;
ycaOut[i].a = ycaIn[13][i].a;
}
}
void
YCAtoRGBA (const IMATH_NAMESPACE::V3f &yw,
int n,
const Rgba ycaIn[/*n*/],
Rgba rgbaOut[/*n*/])
{
for (int i = 0; i < n; ++i)
{
const Rgba &in = ycaIn[i];
Rgba &out = rgbaOut[i];
if (in.r == 0 && in.b == 0)
{
//
// Special case -- both chroma channels are 0. To avoid
// rounding errors, we explicitly set the output R, G and B
// channels equal to the input luminance.
//
// The special cases here and in RGBAtoYCA() ensure that
// converting black-and white images from RGBA to YCA and
// back is lossless.
//
out.r = in.g;
out.g = in.g;
out.b = in.g;
out.a = in.a;
}
else
{
float Y = in.g;
float r = (in.r + 1) * Y;
float b = (in.b + 1) * Y;
float g = (Y - r * yw.x - b * yw.z) / yw.y;
out.r = r;
out.g = g;
out.b = b;
out.a = in.a;
}
}
}
namespace {
inline float
saturation (const Rgba &in)
{
float rgbMax = max (in.r, max (in.g, in.b));
float rgbMin = min (in.r, min (in.g, in.b));
if (rgbMax > 0)
return 1 - rgbMin / rgbMax;
else
return 0;
}
void
desaturate (const Rgba &in, float f, const V3f &yw, Rgba &out)
{
float rgbMax = max (in.r, max (in.g, in.b));
out.r = max (float (rgbMax - (rgbMax - in.r) * f), 0.0f);
out.g = max (float (rgbMax - (rgbMax - in.g) * f), 0.0f);
out.b = max (float (rgbMax - (rgbMax - in.b) * f), 0.0f);
out.a = in.a;
float Yin = in.r * yw.x + in.g * yw.y + in.b * yw.z;
float Yout = out.r * yw.x + out.g * yw.y + out.b * yw.z;
if (Yout > 0)
{
out.r *= Yin / Yout;
out.g *= Yin / Yout;
out.b *= Yin / Yout;
}
}
} // namespace
void
fixSaturation (const IMATH_NAMESPACE::V3f &yw,
int n,
const Rgba * const rgbaIn[3],
Rgba rgbaOut[/*n*/])
{
float neighborA2 = saturation (rgbaIn[0][0]);
float neighborA1 = neighborA2;
float neighborB2 = saturation (rgbaIn[2][0]);
float neighborB1 = neighborB2;
for (int i = 0; i < n; ++i)
{
float neighborA0 = neighborA1;
neighborA1 = neighborA2;
float neighborB0 = neighborB1;
neighborB1 = neighborB2;
if (i < n - 1)
{
neighborA2 = saturation (rgbaIn[0][i + 1]);
neighborB2 = saturation (rgbaIn[2][i + 1]);
}
//
// A0 A1 A2
// rgbaOut[i]
// B0 B1 B2
//
float sMean = min (1.0f, 0.25f * (neighborA0 + neighborA2 +
neighborB0 + neighborB2));
const Rgba &in = rgbaIn[1][i];
Rgba &out = rgbaOut[i];
float s = saturation (in);
if (s > sMean)
{
float sMax = min (1.0f, 1 - (1 - sMean) * 0.25f);
if (s > sMax)
{
desaturate (in, sMax / s, yw, out);
continue;
}
}
out = in;
}
}
} // namespace RgbaYca
OPENEXR_IMF_INTERNAL_NAMESPACE_SOURCE_EXIT