diff options
| -rw-r--r-- | fitz/filt_predict.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/fitz/filt_predict.c b/fitz/filt_predict.c index 5fbd7d1d..ebd712fd 100644 --- a/fitz/filt_predict.c +++ b/fitz/filt_predict.c @@ -63,9 +63,11 @@ fz_predict_tiff(fz_predict *state, unsigned char *out, unsigned char *in, int le { int left[MAXC]; int i, k; + const int mask = (1 << state->bpc)-1; for (k = 0; k < state->colors; k++) left[k] = 0; + memset(out, 0, state->stride); for (i = 0; i < state->columns; i++) { @@ -73,7 +75,7 @@ fz_predict_tiff(fz_predict *state, unsigned char *out, unsigned char *in, int le { int a = getcomponent(in, i * state->colors + k, state->bpc); int b = a + left[k]; - int c = b % (1 << state->bpc); + int c = b & mask; putcomponent(out, i * state->colors + k, state->bpc, c); left[k] = c; } |