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Diffstat (limited to 'pkg/plot/crtpict/calchgms.x')
| -rw-r--r-- | pkg/plot/crtpict/calchgms.x | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/pkg/plot/crtpict/calchgms.x b/pkg/plot/crtpict/calchgms.x new file mode 100644 index 00000000..15c5aa5a --- /dev/null +++ b/pkg/plot/crtpict/calchgms.x @@ -0,0 +1,192 @@ +# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc. + +include <imhdr.h> +include "wdes.h" +include "crtpict.h" + +# CRT_LINEAR_HGRAM -- Calculate two histograms of an image. One histogram +# shows the distribution of intensities in the untransformed image; the other +# shows the distribution of greyscale values in the transformed image. This +# procedure assumes a linear transformation. + +procedure crt_linear_hgram (im, gp, z1, z2, ztrans, inten_hgram,greys_hgram) + +pointer im # Pointer to image +pointer gp # Graphics descriptor +real z1, z2 # Range of intensities mapped +int ztrans # Type of transfer function - linear or unitary +int inten_hgram[NBINS] # Output array of intensity hgram values +int greys_hgram[NBINS] # Output array of greyscale hgram values + +pointer buf +int npix, nsig_bits, zrange, mask, min_val, max_val +long v[IM_MAXDIM] +int dz1, dz2, high_zi, low_zi +real high_z, low_z +bool ggetb() +pointer imgnlr(), imgnli() +int ggeti() +errchk im_minmax, ggeti, imgnli, imgnlr + +begin + # If z1 and z2 not in graphcap, set to some reasonable numbers for + # plots to be generated. + if (ggetb (gp, "z1") && ggetb (gp, "z2")) { + dz1 = ggeti (gp, "z1") + dz2 = ggeti (gp, "z2") + } else { + dz1 = 0 + dz2 = 255 + } + + # Calculate number of bits of depth in output device + zrange = ggeti (gp, "zr") + for (nsig_bits = 0; ; nsig_bits = nsig_bits + 1) { + zrange = zrange / 2 + if (zrange == 0) + break + } + mask = (2 ** (nsig_bits)) - 1 + + call aclri (inten_hgram, NBINS) + call aclri (greys_hgram, NBINS) + call amovkl (long(1), v, IM_MAXDIM) + + # Read lines into buffer and accumulate histograms. + npix = IM_LEN(im,1) + + if (ztrans == W_UNITARY) { + min_val = int (IM_MIN(im)) + max_val = int (IM_MAX(im)) + while (imgnli (im, buf, v) != EOF) { + call ahgmi (Memi[buf], npix, inten_hgram, NBINS, min_val, + max_val) + call aandki (Memi[buf], mask, Memi[buf], npix) + call ahgmi (Memi[buf], npix, greys_hgram, NBINS, dz1, dz2) + } + } else if (IM_PIXTYPE(im) == TY_SHORT) { + min_val = int (IM_MIN(im)) + max_val = int (IM_MAX(im)) + if (z2 > z1) { + # Positive contrast + high_zi = int (z2) + low_zi = int (z1) + } else { + # Negative contrast + high_zi = int (z1) + low_zi = int (z2) + } + while (imgnli (im, buf, v) != EOF) { + call ahgmi (Memi[buf], npix, inten_hgram, NBINS, min_val, + max_val) + call ahgmi (Memi[buf], npix, greys_hgram, NBINS, low_zi, + high_zi) + } + } else { + if (z2 > z1) { + # Positive contrast + high_z = z2 + low_z = z1 + } else { + # Negative contrast + high_z = z1 + low_z = z2 + } + while (imgnlr (im, buf, v) != EOF) { + call ahgmr (Memr[buf], npix, inten_hgram, NBINS, IM_MIN(im), + IM_MAX(im)) + call ahgmr (Memr[buf], npix, greys_hgram, NBINS, low_z, high_z) + } + } +end + + +# CRT_USER_HGRAM -- Calculate two histograms of an image. One histogram +# shows the distribution of intensities in the untransformed image; the other +# shows the distribution of greyscale values in the transformed image. This +# procedure does not assume a linear transformation, but rather uses a user +# specified look up table. + +procedure crt_user_hgram (im, gp, z1, z2, lut, inten_hgram, greys_hgram) + +pointer im # Pointer to image +pointer gp # Graphics descriptor +real z1, z2 # Range of intensities mapped +short lut[ARB] # Look up table previously calculated +int inten_hgram[NBINS] # Output array of intensity hgram values +int greys_hgram[NBINS] # Output array of greyscale hgram values + +pointer buf, ibuf, sp, rlut +short min_val, max_val, short_min, short_max, dz1, dz2 +int npix +long v[IM_MAXDIM] +short high_zi, low_zi +real high_z, low_z +pointer imgnlr(), imgnls() +errchk im_minmax, imgnls, imgnlr + +begin + # Get max and min in look up table + call alims (lut, SZ_BUF, dz1, dz2) + + call aclri (inten_hgram, NBINS) + call aclri (greys_hgram, NBINS) + call amovkl (long(1), v, IM_MAXDIM) + + # Read lines into buffer and accumulate histograms. + npix = IM_LEN(im,1) + + if (IM_PIXTYPE(im) == TY_SHORT) { + min_val = short (IM_MIN(im)) + max_val = short (IM_MAX(im)) + short_min = short (STARTPT) + short_max = short (ENDPT) + + if (z2 > z1) { + # Positive contrast + high_zi = short (z2) + low_zi = short (z1) + } else { + # Negative contrast + high_zi = short (z1) + low_zi = short (z2) + } + + while (imgnls (im, buf, v) != EOF) { + call ahgms (Mems[buf], npix, inten_hgram, NBINS, min_val, + max_val) + call amaps (Mems[buf], Mems[buf], npix, low_zi, high_zi, + short_min, short_max) + call aluts (Mems[buf], Mems[buf], npix, lut) + call ahgms (Mems[buf], npix, greys_hgram, NBINS, dz1, dz2) + } + } else { + if (z2 > z1) { + # Positive contrast + high_z = z2 + low_z = z1 + } else { + # Negative contrast + high_z = z1 + low_z = z2 + } + + call smark (sp) + call salloc (ibuf, npix, TY_INT) + call salloc (rlut, SZ_BUF, TY_REAL) + call achtsr (lut, Memr[rlut], SZ_BUF) + + while (imgnlr (im, buf, v) != EOF) { + call ahgmr (Memr[buf], npix, inten_hgram, NBINS, IM_MIN(im), + IM_MAX(im)) + + call amapr (Memr[buf], Memr[buf], npix, z1, z2, STARTPT, ENDPT) + call achtri (Memr[buf], Memi[ibuf], npix) + call alutr (Memi[ibuf], Memr[buf], npix, Memr[rlut]) + call ahgmr (Memr[buf], npix, greys_hgram, NBINS, real (dz1), + real (dz2)) + } + + call sfree (sp) + } +end |