| 38 |
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| 39 |
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extern char *progname; |
| 40 |
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|
| 41 |
< |
float *exptable; /* exponent table */ |
| 41 |
> |
float *gausstable; /* gauss lookup table */ |
| 42 |
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|
| 43 |
< |
#define lookexp(x) exptable[(int)(-10.*(x)+.5)] |
| 43 |
> |
#define lookgauss(x) gausstable[(int)(-10.*(x)+.5)] |
| 44 |
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| 45 |
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| 46 |
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initmask() /* initialize gaussian lookup table */ |
| 47 |
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{ |
| 48 |
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extern char *malloc(); |
| 49 |
+ |
double d; |
| 50 |
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register int x; |
| 51 |
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|
| 52 |
< |
exptable = (float *)malloc(100*sizeof(float)); |
| 53 |
< |
if (exptable == NULL) { |
| 52 |
> |
gausstable = (float *)malloc(100*sizeof(float)); |
| 53 |
> |
if (gausstable == NULL) { |
| 54 |
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fprintf(stderr, "%s: out of memory in initmask\n", progname); |
| 55 |
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quit(1); |
| 56 |
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} |
| 57 |
< |
for (x = 0; x < 100; x++) |
| 58 |
< |
exptable[x] = exp(-x*0.1); |
| 57 |
> |
d = x_c*y_r*0.25/rad/rad; |
| 58 |
> |
gausstable[0] = exp(-d)/sqrt(d); |
| 59 |
> |
for (x = 1; x < 100; x++) |
| 60 |
> |
if ((gausstable[x] = exp(-x*0.1)/sqrt(x*0.1)) > gausstable[0]) |
| 61 |
> |
gausstable[x] = gausstable[0]; |
| 62 |
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} |
| 63 |
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| 64 |
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| 119 |
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if (x < 0) continue; |
| 120 |
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if (x >= xres) break; |
| 121 |
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dx = (x_c*(x+.5) - (c+.5))/rad; |
| 122 |
< |
weight = lookexp(-(dx*dx + dy*dy)); |
| 122 |
> |
weight = lookgauss(-(dx*dx + dy*dy)); |
| 123 |
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wsum += weight; |
| 124 |
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copycolor(ctmp, scan[x]); |
| 125 |
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scalecolor(ctmp, weight); |
