Subject: Re: Converting to zebra (ZPL) format - msg#00041

Thanks Douglas and Jaos for your replies.

I made some progress today by using PIL today. I managed to load the image and
cycle through the raw image data. The code is below. I'll look at your
suggestion tomorrow, Douglas. The string types methods sound a bit more
useful than my fumblings. As I said, I'm a newbie. About the spaces mixed
with tabs, I'm using GVIM to edit the code but I'm one of those people who
over-formats code. I like it to look orderly using whatever means comes to
hand.

My code produces a string of 1s and zeros corresponding to the image. I'll
work out a way of converting it to ascii-hex tomorrow. The old code was an
attempt to de-compress pcx data but I don't need to do that if I use PIL. If
I convert the image to mono I should be able to use any source image.

Ideally, I should be able to produce a decoder plug-in for ZPL but I have a
lot to learn before that happens. Given the lack of hits I got while looking
for a ready-made converter, there is not much demand for such a plug-in. Ah
well, if it get it working I'll make it available and then work on others for
DPL, Datamax Programming Language and BPL, Brady Programming Language. I may
need one for Citizen ticket printers also.

I'll stop rambling, here's my code.

Thanks folks,

Peter

#! /usr/bin/env python

import Image, sys, string

def hexit(n): # convert n to two digit Hex string.
result = string.upper(str(hex(ord(n))))[2:4]
if len(result) == 1:
result = '0' + result
return result

def ImageWidth(n): # read image width from PCX header
if n % 8 > 0: # if mod width non zero image needs extra byte
n = n / 8 + 1
else:
n = n / 8
return n

def ImageHeight(n): # read height from PCX header
return 1 + (ord(n[10]) + ord(n[11]) * 256) - (ord(n[6]) + ord(n[7]) *
256)

def PrintDetails(n):
print 'Input length:\t', len(n)
print 'Image Width: \t', ImageWidth(n), ' bytes'

def hex2dec(n): # convert hex digit to decimal
return string.find('0123456789ABCDEF',n)

def invhex(n): # forgot that printer treats 1 as 'on' - no ink dot.
n = string.upper(hex(255 - hex2dec(n[0])*16 - hex2dec(n[1]))[2:])
if len(n) == 2:
return n
else:
return '0'+n

i = sys.argv[1:]

for arg in i:
try:
source = Image.open(arg)
except IOError:
print 'cannot open', arg
else:
dest = arg
dest = dest[:string.find(dest,'.')]+'.hex'
print 'Input file:\t\t', i[0]
print 'Output file:\t\t', dest
width=source.size[0]
print 'Image Width (px):\t', width,' px'
height=source.size[1]
print 'Image Height (px):\t', height,' px'
print 'Image Mode: \t\t', source.mode
hexwidth=ImageWidth(width)
print 'HexWidth:\t\t',hexwidth
header = '~DG_ZEBRA,' + str(hexwidth*height) + ',' + str(hexwidth) +
',\n'
print header

n = ''
for y in range(height):
for x in range(width):
pixel= source.getpixel((x,y))
if pixel==255:
pixel=1
n=n+ str(pixel)
print n

del(source)

#f=file(dest,"w")
#f.write(n)
#f.close()



On Sunday 19 Jun 2005 09:37, Douglas Bagnall wrote:
> hi Peter,
>
> > Thanks for the reply folks. Here is the code I have produced so far...
> > #! /usr/bin/python
> >
> > import sys
> > import string
<SNIP>
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