| 49 |
|
return(-1); |
| 50 |
|
} |
| 51 |
|
/* discard header */ |
| 52 |
< |
getheader(input, NULL); |
| 52 |
> |
if (checkheader(input, COLRFMT, NULL) < 0) { |
| 53 |
> |
fprintf(stderr, "%s: not a Radiance picture\n", fname); |
| 54 |
> |
return(-1); |
| 55 |
> |
} |
| 56 |
|
/* get picture dimensions */ |
| 57 |
|
if (fgetresolu(&xres, &yres, input) != (YMAJOR|YDECR)) { |
| 58 |
|
fprintf(stderr, "%s: bad picture size\n", fname); |
| 118 |
|
register int x; |
| 119 |
|
{ |
| 120 |
|
static int cerr[NCOLS]; |
| 121 |
< |
static int err; |
| 121 |
> |
static int err, errp; |
| 122 |
|
int b; |
| 123 |
|
register int isblack; |
| 124 |
|
|
| 125 |
|
b = normbright(clr); |
| 126 |
+ |
errp = err; |
| 127 |
|
err += b + cerr[x]; |
| 128 |
|
isblack = err < 128; |
| 129 |
|
if (!isblack) err -= 256; |
| 130 |
< |
cerr[x] = err /= 2; |
| 130 |
> |
err /= 3; |
| 131 |
> |
cerr[x] = err + errp; |
| 132 |
|
return(isblack); |
| 133 |
|
} |
