1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
include <imhdr.h>
include <imset.h>
include <imio.h>
# IMBTRAN -- Transform a point (x,y), possibly lying outside the boundary of
# the N-dimensional image, back into the image using the current boundary
# extension technique.
procedure imbtran (im, v1, v2, ndim)
pointer im # image descriptor
long v1[IM_MAXDIM] # input, out of bounds point
long v2[IM_MAXDIM] # transformed point (output)
int ndim # number of dimensions to transform
int i
long vin, vmax
begin
switch (IM_VTYBNDRY(im)) {
case BT_NEAREST:
do i = 1, ndim {
vmax = IM_SVLEN(im,i)
vin = v1[i]
if (vin < 1)
v2[i] = 1
else if (vin > vmax)
v2[i] = vmax
else
v2[i] = vin
}
case BT_REFLECT:
do i = 1, ndim {
vmax = IM_SVLEN(im,i)
vin = v1[i]
if (vin < 1)
v2[i] = 1 + (1 - vin)
else if (vin > vmax)
v2[i] = vmax - (vin - vmax)
else
v2[i] = vin
}
case BT_WRAP:
do i = 1, ndim {
vmax = IM_SVLEN(im,i)
vin = v1[i]
while (vin < 1)
vin = vin + vmax
while (vin > vmax)
vin = vin - vmax
v2[i] = vin
}
default:
do i = 1, ndim
v2[i] = v1[i]
}
end
|
