Simple photo collage using Python and PIL

[Callum Prentice]

i need a "script" that i can use locally as well as online that will:

* create a large (maybe something like 2k x 2k) master image in memory
* open a text file and read all the lines from it (maybe 1000 lines
max)
* each line is composed of an x, y, name and a png image filename
* for each line, open the png image and position it in the master
image at the location given by x & y
* save off the master image to a png at the end

i've been told python and the python image library can help me - i
haven't used either before so can anyone give me some pointers to get
me started please - it feels like it's probably just a few lines of
code for an expert (no validation required - i'll be the only one using
it)

any help much appreciated.

-- cal

[Thomas Guettler]

Re: Simple photo collage using Python and PIL

Am Tue, 22 Nov 2005 16:10:10 -0800 schrieb Callum Prentice:
[color=blue]
> i need a "script" that i can use locally as well as online that will:
>
> * create a large (maybe something like 2k x 2k) master image in memory
> * open a text file and read all the lines from it (maybe 1000 lines
> max)
> * each line is composed of an x, y, name and a png image filename
> * for each line, open the png image and position it in the master
> image at the location given by x & y
> * save off the master image to a png at the end[/color]

Hi,

I would convert[1] the image to binary pnm[2]. This is a very easy
uncompressed image format. You don't need PIL to parse it.

Read the file into memory. You could use a matrix:

pic[0][0] first pixel
pic[-1][-1] last pixel

Then you coping or changing pixels is easy:

for x in xrange(?, ?):
for y in xrange(?, ?):
...

At the end create png from pnm with convert.

I hope this helps.

Thomas

[1] convert: http://www.imagemagick.org
[2] pnm: http://netpbm.sourceforge.net/doc/pnm.html

--
Thomas Güttler, http://www.thomas-guettler.de/
E-Mail: guettli (*) thomas-guettler + de
Spam Catcher: niemand.leerman n@thomas-guettler.de

[Fredrik Lundh]

Re: Simple photo collage using Python and PIL

Callum Prentice wrote:
[color=blue]
> i need a "script" that i can use locally as well as online that will:
>
> * create a large (maybe something like 2k x 2k) master image in memory
> * open a text file and read all the lines from it (maybe 1000 lines
> max)
> * each line is composed of an x, y, name and a png image filename
> * for each line, open the png image and position it in the master
> image at the location given by x & y
> * save off the master image to a png at the end
>
> i've been told python and the python image library can help me - i
> haven't used either before so can anyone give me some pointers to get
> me started please - it feels like it's probably just a few lines of
> code for an expert (no validation required - i'll be the only one using
> it)
>
> any help much appreciated.[/color]

the three first sections in the PIL handbook discusses how to create,
load, save, and cut/paste images.

here's an outline:

import Image

out = Image.new("RGB" , (2048, 2048), "white")

for line in open("myfile.tx t"):
x, y, name, pngfile = line.split()
out.paste(Image .open(pngfile), (int(x), int(y)))

out.save("out.p ng")

this assumes that the text file is named "myfile.txt ", and contains white-
space separated items.

if you're new to both tools, skimming the tutorials before you start tinkering
will most likely save you some time later on:

http://docs.python.org/tut/tut.html

http://www.pythonware.com/library/pi...troduction.htm

</F>

[Callum Prentice]

Re: Simple photo collage using Python and PIL

Thank you Thomas - I've heard good things about Image Magick - I'll go
read up on it.

Cheers.

Cal.

[Callum Prentice]

Re: Simple photo collage using Python and PIL

Thanks very much Fredrik - just what I was looking for - that gives me
a good place to start from. Much appreciated.

Cal.