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/*
* Copyright 2011-2016 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __UTIL_IMAGE_IMPL_H__
#define __UTIL_IMAGE_IMPL_H__
#include "util/util_algorithm.h"
#include "util/util_half.h"
#include "util/util_image.h"
CCL_NAMESPACE_BEGIN
namespace {
template<typename T>
const T *util_image_read(const vector<T>& pixels,
const size_t width,
const size_t height,
const size_t /*depth*/,
const size_t components,
const size_t x, const size_t y, const size_t z) {
const size_t index = ((size_t)z * (width * height) +
(size_t)y * width +
(size_t)x) * components;
return &pixels[index];
}
/* Cast input pixel from unknown storage to float. */
template<typename T>
inline float cast_to_float(T value);
template<>
inline float cast_to_float(float value)
{
return value;
}
template<>
inline float cast_to_float(uchar value)
{
return (float)value / 255.0f;
}
template<>
inline float cast_to_float(uint16_t value)
{
return (float)value / 65535.0f;
}
template<>
inline float cast_to_float(half value)
{
return half_to_float(value);
}
/* Cast float value to output pixel type. */
template<typename T>
inline T cast_from_float(float value);
template<>
inline float cast_from_float(float value)
{
return value;
}
template<>
inline uchar cast_from_float(float value)
{
if(value < 0.0f) {
return 0;
}
else if(value > (1.0f - 0.5f / 255.0f)) {
return 255;
}
return (uchar)((255.0f * value) + 0.5f);
}
template<>
inline uint16_t cast_from_float(float value)
{
if(value < 0.0f) {
return 0;
}
else if(value >(1.0f - 0.5f / 65535.0f)) {
return 65535;
}
return (uchar)((65535.0f * value) + 0.5f);
}
template<>
inline half cast_from_float(float value)
{
return float_to_half(value);
}
template<typename T>
void util_image_downscale_sample(const vector<T>& pixels,
const size_t width,
const size_t height,
const size_t depth,
const size_t components,
const size_t kernel_size,
const float x,
const float y,
const float z,
T *result)
{
assert(components <= 4);
const size_t ix = (size_t)x,
iy = (size_t)y,
iz = (size_t)z;
/* TODO(sergey): Support something smarter than box filer. */
float accum[4] = {0};
size_t count = 0;
for(size_t dz = 0; dz < kernel_size; ++dz) {
for(size_t dy = 0; dy < kernel_size; ++dy) {
for(size_t dx = 0; dx < kernel_size; ++dx) {
const size_t nx = ix + dx,
ny = iy + dy,
nz = iz + dz;
if(nx >= width || ny >= height || nz >= depth) {
continue;
}
const T *pixel = util_image_read(pixels,
width, height, depth,
components,
nx, ny, nz);
for(size_t k = 0; k < components; ++k) {
accum[k] += cast_to_float(pixel[k]);
}
++count;
}
}
}
if(count != 0) {
const float inv_count = 1.0f / (float)count;
for(size_t k = 0; k < components; ++k) {
result[k] = cast_from_float<T>(accum[k] * inv_count);
}
}
else {
for(size_t k = 0; k < components; ++k) {
result[k] = T(0.0f);
}
}
}
template<typename T>
void util_image_downscale_pixels(const vector<T>& input_pixels,
const size_t input_width,
const size_t input_height,
const size_t input_depth,
const size_t components,
const float inv_scale_factor,
const size_t output_width,
const size_t output_height,
const size_t output_depth,
vector<T> *output_pixels)
{
const size_t kernel_size = (size_t)(inv_scale_factor + 0.5f);
for(size_t z = 0; z < output_depth; ++z) {
for(size_t y = 0; y < output_height; ++y) {
for(size_t x = 0; x < output_width; ++x) {
const float input_x = (float)x * inv_scale_factor,
input_y = (float)y * inv_scale_factor,
input_z = (float)z * inv_scale_factor;
const size_t output_index =
(z * output_width * output_height +
y * output_width + x) * components;
util_image_downscale_sample(input_pixels,
input_width, input_height, input_depth,
components,
kernel_size,
input_x, input_y, input_z,
&output_pixels->at(output_index));
}
}
}
}
} /* namespace */
template<typename T>
void util_image_resize_pixels(const vector<T>& input_pixels,
const size_t input_width,
const size_t input_height,
const size_t input_depth,
const size_t components,
const float scale_factor,
vector<T> *output_pixels,
size_t *output_width,
size_t *output_height,
size_t *output_depth)
{
/* Early output for case when no scaling is applied. */
if(scale_factor == 1.0f) {
*output_width = input_width;
*output_height = input_height;
*output_depth = input_depth;
*output_pixels = input_pixels;
return;
}
/* First of all, we calculate output image dimensions.
* We clamp them to be 1 pixel at least so we do not generate degenerate
* image.
*/
*output_width = max((size_t)((float)input_width * scale_factor), (size_t)1);
*output_height = max((size_t)((float)input_height * scale_factor), (size_t)1);
*output_depth = max((size_t)((float)input_depth * scale_factor), (size_t)1);
/* Prepare pixel storage for the result. */
const size_t num_output_pixels = ((*output_width) *
(*output_height) *
(*output_depth)) * components;
output_pixels->resize(num_output_pixels);
if(scale_factor < 1.0f) {
const float inv_scale_factor = 1.0f / scale_factor;
util_image_downscale_pixels(input_pixels,
input_width, input_height, input_depth,
components,
inv_scale_factor,
*output_width, *output_height, *output_depth,
output_pixels);
} else {
/* TODO(sergey): Needs implementation. */
}
}
CCL_NAMESPACE_END
#endif /* __UTIL_IMAGE_IMPL_H__ */
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