asgardius/virtualx-engine
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Merge pull request #39617 from mrushyendra/bilinear_interpolation

Browse source 
Fix upscaling image with bilinear interpolation option specified
This commit is contained in:
Rémi Verschelde 2020-06-24 21:58:43 +02:00 committed by GitHub
commit 850134aff9
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
1 changed files with 14 additions and 13 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

27
core/image.cpp
View file

@ -678,34 +678,35 @@ static void _scale_bilinear(const uint8_t *__restrict p_src, uint8_t *__restrict
enum {
FRAC_BITS = 8,
FRAC_LEN = (1 << FRAC_BITS),
FRAC_HALF = (FRAC_LEN >> 1),
FRAC_MASK = FRAC_LEN - 1
};
for (uint32_t i = 0; i < p_dst_height; i++) {
uint32_t src_yofs_up_fp = (i * p_src_height * FRAC_LEN / p_dst_height);
uint32_t src_yofs_frac = src_yofs_up_fp & FRAC_MASK;
uint32_t src_yofs_up = src_yofs_up_fp >> FRAC_BITS;
uint32_t src_yofs_down = (i + 1) * p_src_height / p_dst_height;
// Add 0.5 in order to interpolate based on pixel center
uint32_t src_yofs_up_fp = (i + 0.5) * p_src_height * FRAC_LEN / p_dst_height;
// Calculate nearest src pixel center above current, and truncate to get y index
uint32_t src_yofs_up = src_yofs_up_fp >= FRAC_HALF ? (src_yofs_up_fp - FRAC_HALF) >> FRAC_BITS : 0;
uint32_t src_yofs_down = (src_yofs_up_fp + FRAC_HALF) >> FRAC_BITS;
if (src_yofs_down >= p_src_height) {
src_yofs_down = p_src_height - 1;
}
//src_yofs_up*=CC;
//src_yofs_down*=CC;
// Calculate distance to pixel center of src_yofs_up
uint32_t src_yofs_frac = src_yofs_up_fp & FRAC_MASK;
src_yofs_frac = src_yofs_frac >= FRAC_HALF ? src_yofs_frac - FRAC_HALF : src_yofs_frac + FRAC_HALF;
uint32_t y_ofs_up = src_yofs_up * p_src_width * CC;
uint32_t y_ofs_down = src_yofs_down * p_src_width * CC;
for (uint32_t j = 0; j < p_dst_width; j++) {
uint32_t src_xofs_left_fp = (j * p_src_width * FRAC_LEN / p_dst_width);
uint32_t src_xofs_frac = src_xofs_left_fp & FRAC_MASK;
uint32_t src_xofs_left = src_xofs_left_fp >> FRAC_BITS;
uint32_t src_xofs_right = (j + 1) * p_src_width / p_dst_width;
uint32_t src_xofs_left_fp = (j + 0.5) * p_src_width * FRAC_LEN / p_dst_width;
uint32_t src_xofs_left = src_xofs_left_fp >= FRAC_HALF ? (src_xofs_left_fp - FRAC_HALF) >> FRAC_BITS : 0;
uint32_t src_xofs_right = (src_xofs_left_fp + FRAC_HALF) >> FRAC_BITS;
if (src_xofs_right >= p_src_width) {
src_xofs_right = p_src_width - 1;
}
uint32_t src_xofs_frac = src_xofs_left_fp & FRAC_MASK;
src_xofs_frac = src_xofs_frac >= FRAC_HALF ? src_xofs_frac - FRAC_HALF : src_xofs_frac + FRAC_HALF;
src_xofs_left *= CC;
src_xofs_right *= CC;