_test_OpenCV_jp_file_.py

_test_OpenCV_jp_file_.py

#!/usr/local/bin/python
# -*- coding: utf-8 -*-
'''_test_OpenCV_jp_file_
'''

import sys, os
import numpy as np
from PIL import Image
from matplotlib import pyplot as plt
import cv2

FNAME_J = '_4色型色覚テスト.png'
FNAME_E = '_4colors_sense_test.png'

def imwrite_via_numpy(fn, ext, im):
  if im.ndim == 3: im = cv2.cvtColor(im, cv2.COLOR_RGB2BGR)
  r, buf = cv2.imencode(ext, im)
  if r:
    with open(fn, mode='wb') as f: buf.tofile(f)
  else:
    print('error')

def imread_via_numpy(fn):
  flg = cv2.IMREAD_COLOR # cv2.IMREAD_UNCHANGED
  img = np.fromfile(fn, dtype=np.uint8)
  im = cv2.imdecode(img, flg) # not use cv2.imread for jp file
  if im.ndim == 3: im = cv2.cvtColor(im, cv2.COLOR_BGR2RGB)
  return im

def imwrite_via_PIL(fn, ext, im):
  # Image.fromarray(im.astype(np.uint8)).save(fn) # when im is np.float64 etc
  # Image.fromarray((im * 255).astype(np.uint8)).save(fn) # 0.0 <= im <= 1.0
  Image.fromarray(im).save(fn) # , quality=(1 to 95 default 75) when .jpg

def imread_via_PIL(fn):
  img = Image.open(fn)
  # im = np.array(img, dtype=np.uint8) # OK copied
  im = np.asarray(img, dtype=np.uint8) # OK readonly
  return im

def test_jp_file(fnj, fne):
  fig = plt.figure(figsize=(16, 9), dpi=96)
  ax = fig.add_subplot(1, 1, 1)

  '''
  cv2.initFont(font_struct=struct, font_face=1, hscale=1.0, vscale=1.0,
    shear=0.0, thickness=1, line_type=8)
  cv2.FONT_HERSHEY_SIMPLEX
  cv2.FONT_HERSHEY_PLAIN
  cv2.FONT_HERSHEY_DUPLEX
  cv2.FONT_HERSHEY_COMPLEX
  cv2.FONT_HERSHEY_TRIPLEX
  cv2.FONT_HERSHEY_COMPLEX_SMALL
  cv2.FONT_HERSHEY_SCRIPT_SIMPLEX
  cv2.FONT_HERSHEY_SCRIPT_COMPLEX
  | cv2.FONT_ITALIC (no effect ?)
  '''
  ff = cv2.FONT_HERSHEY_DUPLEX | cv2.FONT_ITALIC # font face
  fs = 1.2 # font scale
  col = (240, 192, 32) # color
  tn = 3 # thickness default 1
  lt = cv2.LINE_AA # lineType cv2.LINE(_8 or _4 or _AA anti aliased) default _8
  blo = False # bottomLeftOrigin default False (character top bottom when True)

  if False:
    im = imread_via_numpy(fnj)
    im = cv2.putText(im, 'R: numpy', (10, 300), ff, fs, col, tn, lt, blo)
  else:
    im = imread_via_PIL(fnj)
    im = cv2.putText(im, 'R: PIL', (10, 300), ff, fs, col, tn, lt, blo)

  if False:
    im = cv2.putText(im, 'W: numpy', (10, 250), ff, fs, col, tn, lt, blo)
    imwrite_via_numpy(fne, '.png', im) # size > via_PIL
  else:
    im = cv2.putText(im, 'W: PIL', (10, 250), ff, fs, col, tn, lt, blo)
    imwrite_via_PIL(fne, '.png', im) # size < via_numpy

  ax.imshow(im)
  plt.show()

if __name__ == '__main__':
  test_jp_file(FNAME_J, FNAME_E)