pil example cutter (snippet)

Python pil example 'cutter'

Functions in program:

• def main(filename = None):

python cutter

Python pil example: cutter

#!/usr/bin/env python3
from re import compile as re_compile
from select import select
from sys import stdin
from time import time
from os.path import exists
from os import listdir, makedirs
from PIL.Image import frombytes, open as fromfile, eval as image_eval, merge as image_merge
from PIL.ImageTk import PhotoImage
from PIL.ImageOps import invert, autocontrast, grayscale, equalize, solarize
from tkinter import Frame, Button, Tk, Label, Canvas, BOTH, TOP, Checkbutton, OptionMenu, StringVar, BooleanVar, Menu, IntVar, LEFT, RIGHT, TOP

''' Program to edit two squares in an image for a two-page book
'''

OVERLAP = 10

class Cap(Frame):
    def __init__(self, filename):
        ' set defaults, create widgets, bind callbacks, start live view '
        self.root = Tk()
        # menu:
        self.menu = Menu(self.root)
        self.root.config(menu=self.menu)
        # bind global keypresses:
        self.root.bind('q', lambda e: self.root.quit())
        self.root.bind('x', lambda e: self.root.quit())
        #self.root.bind('<Enter>', lambda e: self.root.quit())
        self.root.bind('<Left>', lambda e: self.move(-1, 0))
        self.root.bind('<Right>', lambda e: self.move(1, 0))
        self.root.bind('<Up>', lambda e: self.move(0, -1))
        self.root.bind('<Down>', lambda e: self.move(0, 1))
        self.root.bind('<Prior>', lambda e: self.move(0, 0, 1))
        self.root.bind('<Next>', lambda e: self.move(0, 0, -1))
        #
        Frame.__init__(self, self.root)
        self.grid()
        self.x_canvas = Canvas(self, )
        self.x_canvas.pack(side=TOP)
        self.x_canvas.bind('<Button-1>', lambda e: self.move(0, 0))
        self.ox = self.oy = 0
        self.image = fromfile(filename)
        self.orig_dx, self.orig_dy = self.image.size
        self.image.thumbnail((800, 800, ), )
        self.photo = PhotoImage(self.image)
        self.dx, self.dy = self.image.size
        #self.scale = self.dx / self.orig_dx
        self.scale = self.dy / self.orig_dy
        self.x_canvas.create_image(self.dx/2, self.dy/2, image=self.photo)
        # we look for two squares fitting into the rectangle
        if self.dx / 2 + (OVERLAP/2) < self.dy:
            self.ds = self.dx / 2 + (OVERLAP/2) # delta square
            self.oy = (self.dy - self.ds) / 2
        else:
            self.ds = self.dy
            self.ox = (self.dx - self.ds) / 2
        l, r = self.calc()
        self.left_page = self.x_canvas.create_rectangle(*l, outline="blue", width=1)
        self.right_page = self.x_canvas.create_rectangle(*r, outline="red", width=1)
        self.x_canvas.config(width=self.dx, height=self.dy, )
        self.x_canvas.pack(side=TOP)

    def move(self, x, y, d=0):
        self.ox += x
        self.oy += y
        self.ds += d
        l, r = self.calc()
        self.x_canvas.coords(self.left_page, l)
        self.x_canvas.coords(self.right_page, r)

    def calc(self):
        oxL = self.ox
        oy = self.oy
        oxR = self.ox + self.ds - OVERLAP
        return (
            (oxL, oy, oxL + self.ds, oy + self.ds, ),
            (oxR, oy, oxR + self.ds, oy + self.ds, ),
            )

    def calc_real(self):
        oxL = int(self.ox / self.scale)
        oy = int(self.oy / self.scale)
        oxR = int((self.ox + self.ds - OVERLAP) / self.scale)
        ds = int(self.ds / self.scale)
        return (
            (oxL, self.orig_dy - (oy + ds), self.orig_dx - (oxL + ds), oy, ),
            (oxR, self.orig_dy - (oy + ds), self.orig_dx - (oxR + ds), oy, ),
            )

def main(filename = None):
    ' main start point of the program '
    if not filename:
        pattern = re_compile(r'\\AddToShipoutPictureBG\*{\\includegraphics\[[^\]]*\]{(?P<filename>[^}]*)}}')
        # try to guess from stdin / latex pattern
        for x in stdin.readlines():
            match = pattern.match(x)
            if match:
                filename = match.groupdict()['filename']
                break
    app = Cap(filename)
    app.mainloop()
    app.root.destroy()
    left, right = app.calc_real()
    left, right = list(left), list(right),
    print('\\AddToShipoutPictureBG*{{\\includegraphics[width=\\paperwidth,height=\\paperheight,keepaspectratio,clip,trim={}pt {}pt {}pt {}pt]{{{}}}}}'.format(*left + [filename, ]))
    print('\\null\\newpage')
    print('\\AddToShipoutPictureBG*{{\\includegraphics[width=\\paperwidth,height=\\paperheight,keepaspectratio,clip,trim={}pt {}pt {}pt {}pt]{{{}}}}}'.format(*right + [filename, ]))
    print('\\null\\newpage')

if __name__ == '__main__':
    from sys import argv
    main(*argv[1:])
# vim:tw=0:nowrap

Python links

• Learn Python: https://pythonbasics.org/
• Python Tutorial: https://pythonprogramminglanguage.com