aboutsummaryrefslogtreecommitdiff
path: root/pkg/xtools/xtsample.x
diff options
context:
space:
mode:
Diffstat (limited to 'pkg/xtools/xtsample.x')
-rw-r--r--pkg/xtools/xtsample.x362
1 files changed, 362 insertions, 0 deletions
diff --git a/pkg/xtools/xtsample.x b/pkg/xtools/xtsample.x
new file mode 100644
index 00000000..e8184e1d
--- /dev/null
+++ b/pkg/xtools/xtsample.x
@@ -0,0 +1,362 @@
+include <imhdr.h>
+
+
+# XT_SAMPLE -- Get sample of pixels.
+#
+# This routine returns a sample of unmasked pixels from an N-dim image.
+# The input is the image pointer, the mask pointer (which may be NULL),
+# the array to be filled, the maximum number of sample plixels, and the
+# minimum number of lines to sample. The return value is the actual number
+# of pixels which will be less than or equal to the specified maximum number.
+#
+# The intent of this routine is to sample fairly uniformly but efficiently.
+# If nlines is zero the total number of pixels, in raster order, is divided
+# into uniform steps. But this may end up reading many lines each for a
+# few pixels. To be more efficient if nlines is greater than zero then as
+# many pixels per line as possible are read to sample at least the requested
+# number of lines.
+
+
+int procedure xt_samples (im, bpm, sample, nsample, nlines)
+
+pointer im #I Image pointer
+pointer bpm #I Bad pixel pointer
+short sample[nsample] #I Work array
+int nsample #I Maximum number of sample pixels
+int nlines #I Minimum number of lines to sample
+int nreturn #I Number of pixels returned
+
+long v[IM_MAXDIM], vbuf[IM_MAXDIM]
+int i, ip, n, ndim, npix, nc
+real p, c, pstep, cstep
+pointer buf, bpmbuf
+
+int imgnls()
+
+begin
+ # Determine the number of pixels in the data, the number
+ # to make up nsample pixels, and the pixel step.
+
+ ndim = IM_NDIM(im)
+ nc = IM_LEN(im,1)
+ npix = 1
+ do i = 1, ndim
+ npix = npix * IM_LEN(im,i)
+ pstep = real(npix) / min (npix, nsample)
+
+ # To insure a minimum number of lines and efficient use of
+ # pixels in a line, set the column step.
+
+ if (nlines == 0)
+ cstep = pstep
+ else
+ cstep = nc / min (min(npix,nsample)/nlines, nc)
+
+ # Step through the pixels.
+ call amovkl (long(1), v, IM_MAXDIM)
+ nreturn = 0
+ for (p=(pstep-0.01)/2; p<npix && nreturn<nsample;) {
+
+ # Convert pixel number to image vector coordinates.
+ n = npix; ip = nint(p)
+ do i = ndim, 1, -1 {
+ n = n / IM_LEN(im,i)
+ v[i] = 1 + ip / n
+ ip = mod (ip, n)
+ }
+
+ # Sample the pixels in the line.
+ if (nlines == 0)
+ c = v[1]
+ else
+ c = (cstep - 0.01) / 2
+
+ if (bpm == NULL) {
+ v[1] = 1
+ if (imgnls (im, buf, v) == EOF)
+ break
+ for (; c<nc && nreturn<nsample; c=c+cstep) {
+ ip = nint (c)
+ nreturn = nreturn + 1
+ sample[nreturn] = Mems[buf+ip]
+ p = p + pstep
+ }
+ } else {
+ v[1] = 1
+ call amovl (v, vbuf, IM_MAXDIM)
+ if (imgnls (bpm, bpmbuf, vbuf) == EOF)
+ break
+ if (imgnls (im, buf, v) == EOF)
+ break
+ for (; c<nc && nreturn<nsample; c=c+cstep) {
+ ip = nint (c)
+ if (Mems[bpmbuf+ip] == 0) {
+ nreturn = nreturn + 1
+ sample[nreturn] = Mems[buf+ip]
+ }
+ p = p + pstep
+ }
+ }
+ }
+
+ return (nreturn)
+end
+
+int procedure xt_samplei (im, bpm, sample, nsample, nlines)
+
+pointer im #I Image pointer
+pointer bpm #I Bad pixel pointer
+int sample[nsample] #I Work array
+int nsample #I Maximum number of sample pixels
+int nlines #I Minimum number of lines to sample
+int nreturn #I Number of pixels returned
+
+long v[IM_MAXDIM], vbuf[IM_MAXDIM]
+int i, ip, n, ndim, npix, nc
+real p, c, pstep, cstep
+pointer buf, bpmbuf
+
+int imgnls()
+int imgnli()
+
+begin
+ # Determine the number of pixels in the data, the number
+ # to make up nsample pixels, and the pixel step.
+
+ ndim = IM_NDIM(im)
+ nc = IM_LEN(im,1)
+ npix = 1
+ do i = 1, ndim
+ npix = npix * IM_LEN(im,i)
+ pstep = real(npix) / min (npix, nsample)
+
+ # To insure a minimum number of lines and efficient use of
+ # pixels in a line, set the column step.
+
+ if (nlines == 0)
+ cstep = pstep
+ else
+ cstep = nc / min (min(npix,nsample)/nlines, nc)
+
+ # Step through the pixels.
+ call amovkl (long(1), v, IM_MAXDIM)
+ nreturn = 0
+ for (p=(pstep-0.01)/2; p<npix && nreturn<nsample;) {
+
+ # Convert pixel number to image vector coordinates.
+ n = npix; ip = nint(p)
+ do i = ndim, 1, -1 {
+ n = n / IM_LEN(im,i)
+ v[i] = 1 + ip / n
+ ip = mod (ip, n)
+ }
+
+ # Sample the pixels in the line.
+ if (nlines == 0)
+ c = v[1]
+ else
+ c = (cstep - 0.01) / 2
+
+ if (bpm == NULL) {
+ v[1] = 1
+ if (imgnli (im, buf, v) == EOF)
+ break
+ for (; c<nc && nreturn<nsample; c=c+cstep) {
+ ip = nint (c)
+ nreturn = nreturn + 1
+ sample[nreturn] = Memi[buf+ip]
+ p = p + pstep
+ }
+ } else {
+ v[1] = 1
+ call amovl (v, vbuf, IM_MAXDIM)
+ if (imgnls (bpm, bpmbuf, vbuf) == EOF)
+ break
+ if (imgnli (im, buf, v) == EOF)
+ break
+ for (; c<nc && nreturn<nsample; c=c+cstep) {
+ ip = nint (c)
+ if (Mems[bpmbuf+ip] == 0) {
+ nreturn = nreturn + 1
+ sample[nreturn] = Memi[buf+ip]
+ }
+ p = p + pstep
+ }
+ }
+ }
+
+ return (nreturn)
+end
+
+int procedure xt_sampler (im, bpm, sample, nsample, nlines)
+
+pointer im #I Image pointer
+pointer bpm #I Bad pixel pointer
+real sample[nsample] #I Work array
+int nsample #I Maximum number of sample pixels
+int nlines #I Minimum number of lines to sample
+int nreturn #I Number of pixels returned
+
+long v[IM_MAXDIM], vbuf[IM_MAXDIM]
+int i, ip, n, ndim, npix, nc
+real p, c, pstep, cstep
+pointer buf, bpmbuf
+
+int imgnls()
+int imgnlr()
+
+begin
+ # Determine the number of pixels in the data, the number
+ # to make up nsample pixels, and the pixel step.
+
+ ndim = IM_NDIM(im)
+ nc = IM_LEN(im,1)
+ npix = 1
+ do i = 1, ndim
+ npix = npix * IM_LEN(im,i)
+ pstep = real(npix) / min (npix, nsample)
+
+ # To insure a minimum number of lines and efficient use of
+ # pixels in a line, set the column step.
+
+ if (nlines == 0)
+ cstep = pstep
+ else
+ cstep = nc / min (min(npix,nsample)/nlines, nc)
+
+ # Step through the pixels.
+ call amovkl (long(1), v, IM_MAXDIM)
+ nreturn = 0
+ for (p=(pstep-0.01)/2; p<npix && nreturn<nsample;) {
+
+ # Convert pixel number to image vector coordinates.
+ n = npix; ip = nint(p)
+ do i = ndim, 1, -1 {
+ n = n / IM_LEN(im,i)
+ v[i] = 1 + ip / n
+ ip = mod (ip, n)
+ }
+
+ # Sample the pixels in the line.
+ if (nlines == 0)
+ c = v[1]
+ else
+ c = (cstep - 0.01) / 2
+
+ if (bpm == NULL) {
+ v[1] = 1
+ if (imgnlr (im, buf, v) == EOF)
+ break
+ for (; c<nc && nreturn<nsample; c=c+cstep) {
+ ip = nint (c)
+ nreturn = nreturn + 1
+ sample[nreturn] = Memr[buf+ip]
+ p = p + pstep
+ }
+ } else {
+ v[1] = 1
+ call amovl (v, vbuf, IM_MAXDIM)
+ if (imgnls (bpm, bpmbuf, vbuf) == EOF)
+ break
+ if (imgnlr (im, buf, v) == EOF)
+ break
+ for (; c<nc && nreturn<nsample; c=c+cstep) {
+ ip = nint (c)
+ if (Mems[bpmbuf+ip] == 0) {
+ nreturn = nreturn + 1
+ sample[nreturn] = Memr[buf+ip]
+ }
+ p = p + pstep
+ }
+ }
+ }
+
+ return (nreturn)
+end
+
+int procedure xt_sampled (im, bpm, sample, nsample, nlines)
+
+pointer im #I Image pointer
+pointer bpm #I Bad pixel pointer
+double sample[nsample] #I Work array
+int nsample #I Maximum number of sample pixels
+int nlines #I Minimum number of lines to sample
+int nreturn #I Number of pixels returned
+
+long v[IM_MAXDIM], vbuf[IM_MAXDIM]
+int i, ip, n, ndim, npix, nc
+real p, c, pstep, cstep
+pointer buf, bpmbuf
+
+int imgnls()
+int imgnld()
+
+begin
+ # Determine the number of pixels in the data, the number
+ # to make up nsample pixels, and the pixel step.
+
+ ndim = IM_NDIM(im)
+ nc = IM_LEN(im,1)
+ npix = 1
+ do i = 1, ndim
+ npix = npix * IM_LEN(im,i)
+ pstep = real(npix) / min (npix, nsample)
+
+ # To insure a minimum number of lines and efficient use of
+ # pixels in a line, set the column step.
+
+ if (nlines == 0)
+ cstep = pstep
+ else
+ cstep = nc / min (min(npix,nsample)/nlines, nc)
+
+ # Step through the pixels.
+ call amovkl (long(1), v, IM_MAXDIM)
+ nreturn = 0
+ for (p=(pstep-0.01)/2; p<npix && nreturn<nsample;) {
+
+ # Convert pixel number to image vector coordinates.
+ n = npix; ip = nint(p)
+ do i = ndim, 1, -1 {
+ n = n / IM_LEN(im,i)
+ v[i] = 1 + ip / n
+ ip = mod (ip, n)
+ }
+
+ # Sample the pixels in the line.
+ if (nlines == 0)
+ c = v[1]
+ else
+ c = (cstep - 0.01) / 2
+
+ if (bpm == NULL) {
+ v[1] = 1
+ if (imgnld (im, buf, v) == EOF)
+ break
+ for (; c<nc && nreturn<nsample; c=c+cstep) {
+ ip = nint (c)
+ nreturn = nreturn + 1
+ sample[nreturn] = Memd[buf+ip]
+ p = p + pstep
+ }
+ } else {
+ v[1] = 1
+ call amovl (v, vbuf, IM_MAXDIM)
+ if (imgnls (bpm, bpmbuf, vbuf) == EOF)
+ break
+ if (imgnld (im, buf, v) == EOF)
+ break
+ for (; c<nc && nreturn<nsample; c=c+cstep) {
+ ip = nint (c)
+ if (Mems[bpmbuf+ip] == 0) {
+ nreturn = nreturn + 1
+ sample[nreturn] = Memd[buf+ip]
+ }
+ p = p + pstep
+ }
+ }
+ }
+
+ return (nreturn)
+end
+
generated by cgit (git 2.34.1) at 2025-09-20 05:10:02 -0400