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Add padding table.

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We don't set the memory to 0 anymore, we'll use padding.
We can see artifacts in the background for now.
This commit is contained in:
Fabien Freling 2014-08-05 22:13:20 +02:00
parent 4cec5287d7
commit 9dbaafece1
2 changed files with 79 additions and 8 deletions
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1
image.cpp
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@ -35,7 +35,6 @@ Image::Image(unsigned int w, unsigned int h, pnm::Format type)
}
buffer = new pvalue_t[width * height * pixel_size];
memset(buffer, 0, width * height * pixel_size * sizeof (pvalue_t));
}
Image::Image(string const& path)

86
rotation.cpp
View file

@ -123,6 +123,15 @@ void compute_output_size(Image const& src, double const rotation, unsigned int&
height = (int) (max_h - min_h) + 1;
}
DPoint get_mapped_point(Image const& src, Point const& p, double const rotation)
{
DPoint const d = convert_grid_coord(src, p);
double p_angle = 0;
double dist = 0;
convert_abs_to_polar_coord(d, p_angle, dist);
return convert_polar_to_grid_coord(p_angle + rotation, dist);
}
//
@ -149,16 +158,79 @@ bool fequal(float a, float b, float sigma)
//
//
// Image rotation
// Padding
//
DPoint get_mapped_point(Image const& src, Point const& p, double const rotation)
uint16_t* generate_padding_table(Image const& src,
Image const& rotated,
double rotation,
int q_pos)
{
DPoint const d = convert_grid_coord(src, p);
double p_angle = 0;
double dist = 0;
convert_abs_to_polar_coord(d, p_angle, dist);
return convert_polar_to_grid_coord(p_angle + rotation, dist);
uint16_t* padding_table = new uint16_t[rotated.height];
// We suppose the image is square.
double const sigma = 1.0e-5;
if (fequal(rotation, 0, sigma)
|| fequal(rotation, M_PI / 2, sigma)
|| fequal(rotation, M_PI, sigma)
|| fequal(rotation, 3 * M_PI / 2, sigma))
{
memset(padding_table, 0, sizeof (uint16_t) * rotated.height);
return padding_table;
}
double padding_rotation = 0.0;
if (rotation < M_PI / 2)
{
padding_rotation = rotation;
} else if (rotation < M_PI)
{
padding_rotation = rotation - M_PI / 2;
} else if (rotation < 3 * M_PI / 2)
{
padding_rotation = rotation - M_PI;
}
else
{
padding_rotation = rotation - 3 * M_PI / 2;
}
// Quantized delta for padding
// TODO: we should be able to infer these values from qdx and qdy
DPoint const top_left_grid = get_mapped_point(src, Point(0, 0), padding_rotation);
Point const top_left = convert_img_coord(rotated, top_left_grid);
cout << "Padding top left: " << top_left << endl;
DPoint const top_right_grid = get_mapped_point(src, Point(src.width - 1, 0), padding_rotation);
DPoint const top_right = convert_img_coord_precision(rotated, top_right_grid);
Point const q_top_right(top_right.x * q_pos, top_right.y * q_pos);
DPoint const bottom_left_grid = get_mapped_point(src, Point(0, src.height), padding_rotation);
DPoint const bottom_left = convert_img_coord_precision(rotated, bottom_left_grid);
Point const q_bottom_left(bottom_left.x * q_pos, bottom_left.y * q_pos);
int i = 0;
int const q_top_width = q_top_right.x;
int const q_top_step = q_top_width / top_left.y;
int previous_padding = 0;
for (; i <= top_left.y; ++i)
{
padding_table[i] = (q_top_width - i * q_top_step) / q_pos;
previous_padding = padding_table[i];
}
int const remaining_height = rotated.height - 1 - i;
int const q_bottom_width = q_bottom_left.x;
int const q_bottom_step = q_bottom_width / remaining_height;
int remaining_index = 1;
for (; i < (int) rotated.height; ++i, ++remaining_index)
{
padding_table[i] = min((unsigned int) (remaining_index * q_bottom_step) / q_pos,
(unsigned int) rotated.height - 1 - padding_table[rotated.height - 1 - i]);
}
return padding_table;
}
inline