diff options
Diffstat (limited to 'src/GipfelWidget.cxx')
| -rw-r--r-- | src/GipfelWidget.cxx | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/src/GipfelWidget.cxx b/src/GipfelWidget.cxx index 1eb8866..2daea2a 100644 --- a/src/GipfelWidget.cxx +++ b/src/GipfelWidget.cxx @@ -686,6 +686,9 @@ GipfelWidget::get_pixel(GipfelWidget::sample_mode_t m, if (m == GipfelWidget::BILINEAR) { ret = get_pixel_bilinear(img, px + ((double) img->w()) / 2.0, py + ((double) img->h()) / 2.0, r, g, b); + } else if (m == GipfelWidget::BICUBIC) { + ret = get_pixel_bicubic(img, px + ((double) img->w()) / 2.0, + py + ((double) img->h()) / 2.0, r, g, b); } else { ret = get_pixel_nearest(img, px + ((double) img->w()) / 2.0, py + ((double) img->h()) / 2.0, r, g, b); @@ -751,6 +754,53 @@ GipfelWidget::get_pixel_bilinear(Fl_Image *img, double x, double y, } } +static double +interp_cubic(double x, double *v) { + double a0, a1, a2, a3; + double x2 = x * x; + + a0 = v[3] - v[2] - v[0] + v[1]; + a1 = v[0] - v[1] - a0; + a2 = v[2] - v[0]; + a3 = v[1]; + + return a0 * x * x2 +a1 * x2 + a2 * x + a3; +} + +int +GipfelWidget::get_pixel_bicubic(Fl_Image *img, double x, double y, + int *r, int *g, int *b) { + + int fl_x = (int) rint(x); + int fl_y = (int) rint(y); + int ic[3]; + double c[3][4]; + double c1[3][4]; + + for (int iy = 0; iy < 4; iy++) { + for (int ix = 0; ix < 4; ix++) { + if (get_pixel(img, fl_x + ix - 2, fl_y + iy - 2, + &ic[0], &ic[1], &ic[2]) != 0) { + return 1; + } + + for (int l = 0; l < 3; l++) { + c[l][ix] = (double) ic[l]; + } + } + + for (int l = 0; l < 3; l++) { + c1[l][iy] = interp_cubic(x - fl_x, c[l]); + } + } + + *r = (int) rint(interp_cubic(x - fl_x, c1[0])); + *g = (int) rint(interp_cubic(x - fl_x, c1[1])); + *b = (int) rint(interp_cubic(x - fl_x, c1[2])); + + return 0; +} + int GipfelWidget::get_pixel(Fl_Image *img, int x, int y, int *r, int *g, int *b) { |