EasyGen/libs/openexr-2.0.0/IlmImfExamples/previewImageExamples.cpp
2014-01-14 00:49:01 +02:00

218 lines
6.4 KiB
C++

///////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2004, Industrial Light & Magic, a division of Lucas
// Digital Ltd. LLC
//
// 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
// its contributors 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 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
///////////////////////////////////////////////////////////////////////////
//-----------------------------------------------------------------------------
//
// Code examples that show how to add preview images
// (also known as thumbnais) to OpenEXR image files.
//
//-----------------------------------------------------------------------------
#include <ImfRgbaFile.h>
#include <ImfArray.h>
#include <ImfPreviewImage.h>
#include "ImathFun.h"
#include "drawImage.h"
#include <iostream>
#include "namespaceAlias.h"
using namespace CustomImf;
using namespace std;
using namespace IMATH_NAMESPACE;
unsigned char
gamma (float x)
{
//
// Convert a floating-point pixel value to an 8-bit gamma-2.2
// preview pixel. (This routine is a simplified version of
// how the exrdisplay program transforms floating-point pixel
// values in order to display them on the screen.)
//
x = pow (5.5555f * max (0.f, x), 0.4545f) * 84.66f;
return (unsigned char) clamp (x, 0.f, 255.f);
}
void
makePreviewImage (const Array2D <Rgba> &pixels,
int width,
int height,
Array2D <PreviewRgba> &previewPixels,
int &previewWidth,
int &previewHeight)
{
const int N = 8;
previewWidth = width / N;
previewHeight = height / N;
previewPixels.resizeErase (previewHeight, previewWidth);
for (int y = 0; y < previewHeight; ++y)
{
for (int x = 0; x < previewWidth; ++x)
{
const Rgba &inPixel = pixels[y * N][x * N];
PreviewRgba &outPixel = previewPixels[y][x];
outPixel.r = gamma (inPixel.r);
outPixel.g = gamma (inPixel.g);
outPixel.b = gamma (inPixel.b);
outPixel.a = int (clamp (inPixel.a * 255.f, 0.f, 255.f) + 0.5f);
}
}
}
void
writeRgbaWithPreview1 (const char fileName[],
const Array2D <Rgba> &pixels,
int width,
int height)
{
//
// Write an image file with a preview image, version 1:
//
// - generate the preview image by subsampling the main image
// - generate a file header
// - add the preview image to the file header
// - open the file (this stores the header with the
// preview image in the file)
// - describe the memory layout of the main image's pixels
// - store the main image's pixels in the file
//
Array2D <PreviewRgba> previewPixels;
int previewWidth;
int previewHeight;
makePreviewImage (pixels, width, height,
previewPixels, previewWidth, previewHeight);
Header header (width, height);
header.setPreviewImage
(PreviewImage (previewWidth, previewHeight, &previewPixels[0][0]));
RgbaOutputFile file (fileName, header, WRITE_RGBA);
file.setFrameBuffer (&pixels[0][0], 1, width);
file.writePixels (height);
}
void
writeRgbaWithPreview2 (const char fileName[],
int width,
int height)
{
//
// Write an image file with a preview image, version 2:
//
// - generate a file header
// - add a dummy preview image to the file header
// - open the file (this stores the header with the dummy
// preview image in the file)
// - render the main image's pixels one scan line at a time,
// and store each scan line in the file before rendering
// the next scan line
// - generate the preview image on the fly, while the main
// image is being rendered
// - once the main image has been rendered, store the preview
// image in the file, overwriting the dummy preview
//
Array <Rgba> pixels (width);
const int N = 8;
int previewWidth = width / N;
int previewHeight = height / N;
Array2D <PreviewRgba> previewPixels (previewHeight, previewWidth);
Header header (width, height);
header.setPreviewImage (PreviewImage (previewWidth, previewHeight));
RgbaOutputFile file (fileName, header, WRITE_RGBA);
file.setFrameBuffer (pixels, 1, 0);
for (int y = 0; y < height; ++y)
{
drawImage7 (pixels, width, height, y);
file.writePixels (1);
if (y % N == 0)
{
for (int x = 0; x < width; x += N)
{
const Rgba &inPixel = pixels[x];
PreviewRgba &outPixel = previewPixels[y / N][x / N];
outPixel.r = gamma (inPixel.r);
outPixel.g = gamma (inPixel.g);
outPixel.b = gamma (inPixel.b);
outPixel.a = int (clamp (inPixel.a * 255.f, 0.f, 255.f) + 0.5f);
}
}
}
file.updatePreviewImage (&previewPixels[0][0]);
}
void
previewImageExamples ()
{
cout << "\nfiles with preview images\n" << endl;
cout << "drawing image then writing file" << endl;
int w = 800;
int h = 600;
Array2D<Rgba> p (h, w);
drawImage1 (p, w, h);
writeRgbaWithPreview1 ("rgbaWithPreview1.exr", p, w, h);
cout << "drawing image while writing file" << endl;
writeRgbaWithPreview2 ("rgbaWithPreview2.exr", w, h);
cout << endl;
}