Scaling an image for printing

wxPython Users
1

Peter,

From: Peter Damoc [mailto:pdamoc@gmail.com]
Sent: Thursday, December 27, 2007 6:06 AM
To: wxPython-users@lists.wxwidgets.org
Subject: Re: [wxPython-users] Scaling an image for printing

  Hi,
  
  I received a feature request of sorts the other day to
allow a user to
  take a screenshot of an application I wrote in wxPython
and print said
  screenshot out. I found Andrea's great script for
getting the screenshot,
  but getting it to print is painful. I am trying to use the
  HtmlEasyPrinting object, which works except that the
image that is sent is
  too large. Is there a way to scale the image in
wxPython to fit letter
  size paper (8 1/2" x 11")?
  
I've shamelessly used the Demo code for scaling an image for
print and got beautiful results... :slight_smile:

After all is just a bitmap... it should work. Take a look. :slight_smile:

Peter

I use stuff from the demo all the time. I suppose what I don't understand
how to do is taking some image that's of an arbitrary size and scaling it
(while keeping the aspect ratio) so that it'll fit on 8 1/2". I don't know
what the size is I should be shooting for, especially if the user happens
to stretch the GUI out of its original proportion.

I have done this in another application, which I think I nabbed from a
post of Andrea's (thanks!):

img = wx.Image(filepath, wx.BITMAP_TYPE_ANY)
# scale the image, preserving the aspect ratio
W = img.GetWidth()
H = img.GetHeight()
if W > H:
    NewW = self.PhotoMaxSize
    NewH = self.PhotoMaxSize * H / W
else:
    NewH = self.PhotoMaxSize
    NewW = self.PhotoMaxSize * W / H
    img = img.Scale(NewW,NewH)

Unfortunately, I am not sure how to apply this to my HtmlWindow such that
I can print from it. Maybe create the snapshot, scale it somehow, save it
and then display it in the HtmlWindow? Still, I need some way of know my
MaxSize...

Any suggestions are good.

Mike

···

-----Original Message-----
On Dec 27, 2007 12:26 AM, Mike Driscoll > <mdriscoll@co.marshall.ia.us> wrote:

2

Mike Driscoll wrote:

I use stuff from the demo all the time. I suppose what I don't understand
how to do is taking some image that's of an arbitrary size and scaling it
(while keeping the aspect ratio) so that it'll fit on 8 1/2". I don't know
what the size is I should be shooting for, especially if the user happens
to stretch the GUI out of its original proportion.

I have done this in another application, which I think I nabbed from a
post of Andrea's (thanks!):

img = wx.Image(filepath, wx.BITMAP_TYPE_ANY)
# scale the image, preserving the aspect ratio
W = img.GetWidth()
H = img.GetHeight()
if W > H:
    NewW = self.PhotoMaxSize
    NewH = self.PhotoMaxSize * H / W
else:
    NewH = self.PhotoMaxSize
    NewW = self.PhotoMaxSize * W / H
    img = img.Scale(NewW,NewH)

Unfortunately, I am not sure how to apply this to my HtmlWindow such that
I can print from it. Maybe create the snapshot, scale it somehow, save it
and then display it in the HtmlWindow? Still, I need some way of know my
MaxSize...

If you're going to be printing via HtmlEasyPrinting then it will already do the scaling such that it will appear on the page approximately how it appears on screen. So just do your image and html in a way that looks on screen how you want it.

To be more accurate you'll want to do the scaling yourself and use the normal printing framework.

···

--
Robin Dunn
Software Craftsman
http://wxPython.org Java give you jitters? Relax with wxPython!