diff options
| -rw-r--r-- | apps/pdfdraw.c | 3 | ||||
| -rw-r--r-- | fitz/fitz.h | 1 | ||||
| -rw-r--r-- | fitz/res_pixmap.c | 20 |
3 files changed, 24 insertions, 0 deletions
diff --git a/apps/pdfdraw.c b/apps/pdfdraw.c index d79cd75c..9ad2b56c 100644 --- a/apps/pdfdraw.c +++ b/apps/pdfdraw.c @@ -189,6 +189,9 @@ static void drawpage(pdf_xref *xref, int pagenum) if (gamma_value != 1) fz_gamma_pixmap(pix, gamma_value); + if (savealpha) + fz_unmultiply_pixmap(pix); + if (output) { char buf[512]; diff --git a/fitz/fitz.h b/fitz/fitz.h index ccaa98b8..d0054f3e 100644 --- a/fitz/fitz.h +++ b/fitz/fitz.h @@ -626,6 +626,7 @@ void fz_clear_pixmap_with_color(fz_pixmap *pix, int value); void fz_clear_pixmap_rect_with_color(fz_pixmap *pix, int value, fz_bbox r); void fz_copy_pixmap_rect(fz_pixmap *dest, fz_pixmap *src, fz_bbox r); void fz_premultiply_pixmap(fz_pixmap *pix); +void fz_unmultiply_pixmap(fz_pixmap *pix); fz_pixmap *fz_alpha_from_gray(fz_pixmap *gray, int luminosity); fz_bbox fz_bound_pixmap(fz_pixmap *pix); void fz_invert_pixmap(fz_pixmap *pix); diff --git a/fitz/res_pixmap.c b/fitz/res_pixmap.c index 83f46526..b1f151c3 100644 --- a/fitz/res_pixmap.c +++ b/fitz/res_pixmap.c @@ -226,6 +226,26 @@ fz_premultiply_pixmap(fz_pixmap *pix) } } +void +fz_unmultiply_pixmap(fz_pixmap *pix) +{ + unsigned char *s = pix->samples; + int a, inva; + int k, x, y; + + for (y = 0; y < pix->h; y++) + { + for (x = 0; x < pix->w; x++) + { + a = s[pix->n - 1]; + inva = a ? 255 * 256 / a : 0; + for (k = 0; k < pix->n - 1; k++) + s[k] = (s[k] * inva) >> 8; + s += pix->n; + } + } +} + fz_pixmap * fz_alpha_from_gray(fz_pixmap *gray, int luminosity) { |