[python-win32] Question about Python script

[Tim Roberts]

Schoeni, Yann wrote:
>
> I’ve recently start to work with Python.
>
>  
>
> I’m developing a managment software for a swimming pool, this software
> needs to print stuff directly from the website.
>
>  
>
> I’m using Ajax request and shell exec to call a Python script which
> launch the print job.
>

Now, do you understand that this will print on the machine where the web
server runs, NOT the web browser?  Many people, when they click on a
"print" button, expect it to print on their local machine, where they
clicked.  Since you have already had results, I assume you are aware of
this.


> The script to print an image works fine with a standard printer but,
> I’ve to print on a card printer (FARGO-DTC1250^e ).
>
>  
>
> When I launch a print job from the website, the python script launch
> the job on the printer, that’s ok.
>
>  
>
> The probleme is that I have a substantial quality deterioration ..The
> image printed on the card looks bad.
>

Can you show us an example? Do you see the whole image, approximately
scaled, but at poor resolution?  Have you tried doing other graphics to
see if it really is a pixel count issue?  Like, if you draw a rectangle
100x100 pixels, does it really appear to be 1/3"?


> I’m sure the problem is about the Python script, I’ve tried to start
> the print job directly from Windows, the image quality is perfect.
>

When you say "start the print job directly from Windows", what do you
mean?  Do you mean, through some mechanism other than the Python script?


>  
>
> I don’t know anymore where to search, eventually when the script draw
> the image ? In this part of the code ?
>
>  
>
> dib = ImageWin.Dib (bmp)
> scaled_width, scaled_height = [int (scale * i) fori inbmp.size]
> x1 = int ((printer_size[0]- scaled_width) / 2)
> y1 = int ((printer_size[1]- scaled_height) / 2)
> x2 = x1 + scaled_width
> y2 = y1 + scaled_height
> dib.draw (hDC.GetHandleOutput (), (x1, y1, x2, y2))
>

This is probably relying on the printer's driver to do the image
resizing, and many printer drivers don't do a good job.  You may need to
scale the image using other PIL features and send a correctly-sized
bitmap to the printer.

-- 
Tim Roberts, timr at probo.com
Providenza & Boekelheide, Inc.