#! /usr/bin/python3 
# Last edited on 2025-08-21 19:52:51 by stolfi

# Reads the raw PGM multispectral images, converts them to numpy arrays
# and saves them to disk.
#
# The parameters are the {page} and the name {clip} of one or more clips.
# 
# The multispectral images are assumed to be in the external directory
# {pgdir_in}, namely "MS/davis/{page}".
# 
# Assumes that there is a file "{pgdir_in}/bands.txt" that specifies the
# names of the bands avaliable for that page (e.g. "MB870IR_030_F"), the
# type of illumination {illum}, and the corresponding {maxval}
# for sample scaling.
#
# The input images are read from "{pgdir_in}/clips/{clip}.pgm", for each
# frontal illumination and narrow reflection band ("MB") {band} listed
# in the "bands.txt" file above. These files are assumed to be 16-bit
# PNG, with the pixel values extracted from the TIFF files
# without any gamma mapping (other than whatever was used to encode
# those file by the scanning team).
#
# The converted images is saved to disk as as a file
# "pages/{page}/clips/{clip}/{band}.npy". Each file contains a matrix
# with shape {(ny,nx)} where {ny} and {ny} are the height and width of
# the clip in pixels.

from math import sin, cos, log, exp, floor, pi, inf
import sys, re, os
import numpy
from PIL import Image
from error_funcs import prog_error, arg_error, debug
from process_funcs import bash, run_command
from bands_table_funcs import read_page_bands_tables
from image_funcs import \
  read_mask_image, read_clip_image, \
  quantize_image, write_image_as_gray_png
import argparser

def main():

  page, clips = parse_options()

  # Read the spectral bands tables:
  bfile = f"MS/davis/{page}/bands.txt"

  # Read dicts mapping band name to illumination type and {maxval} to use:
  bands_tb = read_page_bands_tables(bfile)
  # debug(f"bands_tb[{band}]", bands_tb[band])

  for clip in clips:
    for band in bands_tb.keys():
      illum = bands_tb[band]['illum']
      maxval = bands_tb[band]['maxval']
      sys.stderr.write(f"band {band} illum = {illum} maxval = {maxval:5d}\n")
      if illum == 0 or illum == 1 or illum == 2:
        assert band[0:2] == "MB", "bug: band name should be 'MB')"
      elif illum == 3:
        assert band[0:2] == "TX", "bug: band name should be 'TX'"

      cfile = f"MS/davis/{page}/{band}/clips/{clip}.png"
      sys.stderr.write(f"reading {cfile} ...\n")
      # Read the clip image:
      C = read_clip_image(cfile, maxval)
      assert len(numpy.shape(C)) == 2, "clip image should be monochrome"
      ny, nx = numpy.shape(C)
      fval_min = numpy.min(C, axis=(0,1))
      fval_max = numpy.max(C, axis=(0,1))
      sys.stderr.write(f"{cfile}: rows = {ny:4d} cols = {nx:4d}")
      sys.stderr.write(f" range = [{fval_min:8.6f} _ {fval_max:8.6f}]\n")

      sdir = f"pages/{page}/clips/{clip}"

      bash(f"mkdir -p {sdir}/npy")
      nfile = f"{sdir}/npy/{band}.npy"
      numpy.save(nfile, C)

      bash(f"mkdir -p {sdir}/png")
      pfile = f"{sdir}/png/{band}.png"     
      write_image_as_gray_png(pfile, C)
      sys.stderr.write("%s\n" % ("." * 70))
  return 0
  # ----------------------------------------------------------------------

def parse_options():
  page = sys.argv[1]
  clips = []; iarg = 2
  while iarg < len(sys.argv):
    clip = sys.argv[iarg]    # name of clip to take pixels from.       
    clips.append(clip)
    iarg += 1
  return page, clips
  # ----------------------------------------------------------------------

def band_error(band, msg):
  sys.stderr.write(f"** {band}: {msg}\n")
  assert False
  # ----------------------------------------------------------------------

main()