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Diffstat (limited to 'kimgio/exr.cpp')
| -rw-r--r-- | kimgio/exr.cpp | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/kimgio/exr.cpp b/kimgio/exr.cpp new file mode 100644 index 000000000..e3efe5a6a --- /dev/null +++ b/kimgio/exr.cpp @@ -0,0 +1,167 @@ +// -*- C++;indent-tabs-mode: t; tab-width: 4; c-basic-offset: 4; -*- + +/** +* KImageIO Routines to read (and perhaps in the future, write) images +* in the high dynamic range EXR format. +* Copyright (c) 2003, Brad Hards <bradh@frogmouth.net> +* +* This library is distributed under the conditions of the GNU LGPL. +* +* $Id$ +*/ + +#include "config.h" + +#ifdef HAVE_EXR + +#include <ImfRgbaFile.h> +#include <ImfStandardAttributes.h> +#include <ImathBox.h> +#include <ImfInputFile.h> +#include <ImfBoxAttribute.h> +#include <ImfChannelListAttribute.h> +#include <ImfCompressionAttribute.h> +#include <ImfFloatAttribute.h> +#include <ImfIntAttribute.h> +#include <ImfLineOrderAttribute.h> +#include <ImfStringAttribute.h> +#include <ImfVecAttribute.h> +#include <ImfArray.h> +#include <ImfConvert.h> + +#include <iostream> + +#include <stdlib.h> + +#include <kurl.h> +#include <kprocess.h> +#include <klocale.h> +#include <kgenericfactory.h> +#include <kdebug.h> + +#include <qimage.h> +#include <qcstring.h> +#include <qfile.h> +#include <qdatetime.h> +#include <qdict.h> +#include <qvalidator.h> +#include <qcolor.h> + +#include "exr.h" + +using namespace Imf; + +/* this does a conversion from the ILM Half (equal to Nvidia Half) + * format into the normal 32 bit pixel format. Process is from the + * ILM code. + */ +QRgb RgbaToQrgba(struct Rgba imagePixel) +{ + float r,g,b,a; + + // 1) Compensate for fogging by subtracting defog + // from the raw pixel values. + // Response: We work with defog of 0.0, so this is a no-op + + // 2) Multiply the defogged pixel values by + // 2^(exposure + 2.47393). + // Response: We work with exposure of 0.0. + // (2^2.47393) is 5.55555 + r = imagePixel.r * 5.55555; + g = imagePixel.g * 5.55555; + b = imagePixel.b * 5.55555; + a = imagePixel.a * 5.55555; + + // 3) Values, which are now 1.0, are called "middle gray". + // If defog and exposure are both set to 0.0, then + // middle gray corresponds to a raw pixel value of 0.18. + // In step 6, middle gray values will be mapped to an + // intensity 3.5 f-stops below the display's maximum + // intensity. + // Response: no apparent content. + + // 4) Apply a knee function. The knee function has two + // parameters, kneeLow and kneeHigh. Pixel values + // below 2^kneeLow are not changed by the knee + // function. Pixel values above kneeLow are lowered + // according to a logarithmic curve, such that the + // value 2^kneeHigh is mapped to 2^3.5 (in step 6, + // this value will be mapped to the the display's + // maximum intensity). + // Response: kneeLow = 0.0 (2^0.0 => 1); kneeHigh = 5.0 (2^5 =>32) + if (r > 1.0) + r = 1.0 + Imath::Math<float>::log ((r-1.0) * 0.184874 + 1) / 0.184874; + if (g > 1.0) + g = 1.0 + Imath::Math<float>::log ((g-1.0) * 0.184874 + 1) / 0.184874; + if (b > 1.0) + b = 1.0 + Imath::Math<float>::log ((b-1.0) * 0.184874 + 1) / 0.184874; + if (a > 1.0) + a = 1.0 + Imath::Math<float>::log ((a-1.0) * 0.184874 + 1) / 0.184874; +// +// 5) Gamma-correct the pixel values, assuming that the +// screen's gamma is 0.4545 (or 1/2.2). + r = Imath::Math<float>::pow (r, 0.4545); + g = Imath::Math<float>::pow (g, 0.4545); + b = Imath::Math<float>::pow (b, 0.4545); + a = Imath::Math<float>::pow (a, 0.4545); + +// 6) Scale the values such that pixels middle gray +// pixels are mapped to 84.66 (or 3.5 f-stops below +// the display's maximum intensity). +// +// 7) Clamp the values to [0, 255]. + return qRgba( char (Imath::clamp ( r * 84.66f, 0.f, 255.f ) ), + char (Imath::clamp ( g * 84.66f, 0.f, 255.f ) ), + char (Imath::clamp ( b * 84.66f, 0.f, 255.f ) ), + char (Imath::clamp ( a * 84.66f, 0.f, 255.f ) ) ); +} + +KDE_EXPORT void kimgio_exr_read( QImageIO *io ) +{ + try + { + int width, height; + + // This won't work if io is not QFile ! + RgbaInputFile file (QFile::encodeName(io->fileName())); + Imath::Box2i dw = file.dataWindow(); + + width = dw.max.x - dw.min.x + 1; + height = dw.max.y - dw.min.y + 1; + + Array2D<Rgba> pixels; + pixels.resizeErase (height, width); + + file.setFrameBuffer (&pixels[0][0] - dw.min.x - dw.min.y * width, 1, width); + file.readPixels (dw.min.y, dw.max.y); + + QImage image(width, height, 32, 0, QImage::BigEndian); + if( image.isNull()) + return; + + // somehow copy pixels into image + for ( int y=0; y < height; y++ ) { + for ( int x=0; x < width; x++ ) { + // copy pixels(x,y) into image(x,y) + image.setPixel( x, y, RgbaToQrgba( pixels[y][x] ) ); + } + } + + io->setImage( image ); + io->setStatus( 0 ); + } + catch (const std::exception &exc) + { + kdDebug(399) << exc.what() << endl; + return; + } +} + + +KDE_EXPORT void kimgio_exr_write(QImageIO *) +{ + // TODO: stub +} + + +#endif |