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Do interpolation on quantized values.

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This commit is contained in:
Fabien Freling 2014-07-07 23:19:57 +02:00
parent 0929a51dea
commit 68fb1b1951
1 changed files with 37 additions and 52 deletions
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89
rotation.cpp
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@ -487,8 +487,8 @@ Point convert_img_coord(Image const& img, DPoint const& p)
DPoint convert_img_coord_precision(Image const& img, DPoint const& p) DPoint convert_img_coord_precision(Image const& img, DPoint const& p)
{ {
int x = p.x + (img.width / 2.0f) - 0.5; double x = p.x + (img.width / 2.0f) - 0.5;
int y = p.y + (img.height / 2.0f) - 0.5; double y = p.y + (img.height / 2.0f) - 0.5;
return DPoint(x, y); return DPoint(x, y);
} }
@ -592,21 +592,17 @@ DPoint get_mapped_point(Image const& src, Point const& p, double const rotation)
} }
inline inline
void rotate_pixel(Image const& src, /*uint8_t* rotated,*/ void rotate_pixel(Image const& src,
DPoint const& src_rotated_point, /*Point const& rot_point,*/ Point const& src_rotated_point,
unsigned int const src_limit, unsigned int const rot_limit, unsigned int const src_limit,
uint8_t* rotate_buffer, unsigned int rot_index, uint8_t* rotate_buffer, unsigned int rot_index)
bool full_delta)
{ {
int const src_x = (int) src_rotated_point.x; unsigned int const quantize = 8;
int const src_y = (int) src_rotated_point.y;
unsigned int src_index = (src_y * src.width + src_x) * 3;
// unsigned int rot_index = (rot_point.y * rotated.width + rot_point.x) * 3;
// Out-of-bounds check int const src_x = src_rotated_point.x >> 3;
if (src_index >= src_limit int const src_y = src_rotated_point.y >> 3;
|| rot_index >= rot_limit)
return; unsigned int src_index = (src_y * src.width + src_x) * 3;
// Bilinear interpolation // Bilinear interpolation
unsigned int src_index_1 = src_index; unsigned int src_index_1 = src_index;
@ -614,30 +610,22 @@ void rotate_pixel(Image const& src, /*uint8_t* rotated,*/
unsigned int src_index_3 = src_index_1 + 3 * src.width; unsigned int src_index_3 = src_index_1 + 3 * src.width;
unsigned int src_index_4 = src_index_3 + 3; unsigned int src_index_4 = src_index_3 + 3;
// Out-of-bounds check
if (src_index_4 >= src_limit) if (src_index_4 >= src_limit)
return; return;
// special case if we can directly map the src to the dest unsigned int x_delta = src_rotated_point.x & 0x07;;
if (full_delta) unsigned int y_delta = src_rotated_point.y & 0x07;
{ unsigned int const inv_x = quantize - x_delta;
memcpy(&rotate_buffer[rot_index], &src.buffer[src_index], 3 * sizeof (uint8_t)); unsigned int const inv_y = quantize - y_delta;
return;
}
double x_delta = src_rotated_point.x - src_x;
//round_if_very_small(x_delta);
double y_delta = src_rotated_point.y - src_y;
//round_if_very_small(y_delta);
double const inv_x = 1 - x_delta;
double const inv_y = 1 - y_delta;
// No SIMD // No SIMD
rotate_buffer[rot_index] = (src.buffer[src_index_1] * inv_x + src.buffer[src_index_2] * x_delta) * inv_y rotate_buffer[rot_index] = ((src.buffer[src_index_1] * inv_x + src.buffer[src_index_2] * x_delta) * inv_y
+ (src.buffer[src_index_3] * inv_x + src.buffer[src_index_4] * x_delta) * y_delta; + (src.buffer[src_index_3] * inv_x + src.buffer[src_index_4] * x_delta) * y_delta) >> 6;
rotate_buffer[rot_index + 1] = (src.buffer[src_index_1 + 1] * inv_x + src.buffer[src_index_2 + 1] * x_delta) * inv_y rotate_buffer[rot_index + 1] = ((src.buffer[src_index_1 + 1] * inv_x + src.buffer[src_index_2 + 1] * x_delta) * inv_y
+ (src.buffer[src_index_3 + 1] * inv_x + src.buffer[src_index_4 + 1] * x_delta) * y_delta; + (src.buffer[src_index_3 + 1] * inv_x + src.buffer[src_index_4 + 1] * x_delta) * y_delta) >> 6;
rotate_buffer[rot_index + 2] = (src.buffer[src_index_1 + 2] * inv_x + src.buffer[src_index_2 + 2] * x_delta) * inv_y rotate_buffer[rot_index + 2] = ((src.buffer[src_index_1 + 2] * inv_x + src.buffer[src_index_2 + 2] * x_delta) * inv_y
+ (src.buffer[src_index_3 + 2] * inv_x + src.buffer[src_index_4 + 2] * x_delta) * y_delta; + (src.buffer[src_index_3 + 2] * inv_x + src.buffer[src_index_4 + 2] * x_delta) * y_delta) >> 6;
} }
Image* rotate(Image const& src, double angle) Image* rotate(Image const& src, double angle)
@ -673,13 +661,6 @@ Image* rotate(Image const& src, double angle)
src_delta_y.y = src_delta_y.y - src_origin.y; src_delta_y.y = src_delta_y.y - src_origin.y;
round_if_very_small(src_delta_y.x); round_if_very_small(src_delta_y.x);
round_if_very_small(src_delta_y.y); round_if_very_small(src_delta_y.y);
bool full_delta = false;
if (src_delta_x.x - (int) src_delta_x.x == 0
&& src_delta_x.y - (int) src_delta_x.y == 0
&& src_delta_y.x - (int) src_delta_y.x == 0
&& src_delta_y.y - (int) src_delta_y.y == 0)
full_delta = true;
// // steps for first column in source image (y) // // steps for first column in source image (y)
int origin_nb_steps = max(abs(bl.x - tl.x), abs(bl.y - tl.y)); int origin_nb_steps = max(abs(bl.x - tl.x), abs(bl.y - tl.y));
@ -693,7 +674,6 @@ Image* rotate(Image const& src, double angle)
DPoint const bresenham((tr.x - tl.x) / (float) line_nb_steps, (tr.y - tl.y) / (float) line_nb_steps); DPoint const bresenham((tr.x - tl.x) / (float) line_nb_steps, (tr.y - tl.y) / (float) line_nb_steps);
unsigned int const src_limit = src.width * src.height * 3; unsigned int const src_limit = src.width * src.height * 3;
unsigned int const rot_limit = rotated->width * rotated->height * 3;
DPoint const rot_origin_in_src_grid = get_mapped_point(*rotated, Point(0, 0), -rotation); DPoint const rot_origin_in_src_grid = get_mapped_point(*rotated, Point(0, 0), -rotation);
DPoint const rot_origin_in_src = convert_img_coord_precision(src, rot_origin_in_src_grid); DPoint const rot_origin_in_src = convert_img_coord_precision(src, rot_origin_in_src_grid);
@ -705,24 +685,29 @@ Image* rotate(Image const& src, double angle)
memset(buffer, 0, buffer_size); memset(buffer, 0, buffer_size);
unsigned int buffer_offset = 0; unsigned int buffer_offset = 0;
unsigned int const quantize = 8;
int const& src_qwidth = src.width * quantize;
int const& src_qheight = src.height * quantize;
for (unsigned int y = 0; y < rotated->height; ++y) for (unsigned int y = 0; y < rotated->height; ++y)
{ {
//memset(buffer, 0, buffer_size); Point const src_rotated_point((rot_origin_in_src.x + y * src_delta_y.x) * quantize,
DPoint src_rotated_point(rot_origin_in_src.x + y * src_delta_y.x, (rot_origin_in_src.y + y * src_delta_y.y) * quantize);
rot_origin_in_src.y + y * src_delta_y.y);
for (unsigned int x = 0; x < rotated->width; ++x) for (unsigned int x = 0; x < rotated->width; ++x)
{ {
if (src_rotated_point.x >= 0 && src_rotated_point.x < src.width Point const src_runner(src_rotated_point.x + x * src_delta_x.x * quantize,
&& src_rotated_point.y >= 0 && src_rotated_point.y < src.height) src_rotated_point.y + x * src_delta_x.y * quantize);
if (src_runner.x >= 0 && src_runner.x < src_qwidth
&& src_runner.y >= 0 && src_runner.y < src_qheight)
{ {
rotate_pixel(src, src_rotated_point, rotate_pixel(src, src_runner,
src_limit, rot_limit, src_limit,
buffer, buffer_index * 3, full_delta); buffer, buffer_index * 3);
} }
src_rotated_point.x += src_delta_x.x; // Flush buffer to dest
src_rotated_point.y += src_delta_x.y;
++buffer_index; ++buffer_index;
if (buffer_index == buffer_pixel_capacity) if (buffer_index == buffer_pixel_capacity)
{ {