Scale an image in GTK

Question

In GTK, how can I scale an image? Right now I load images with PIL and scale them beforehand, but is there a way to do it with GTK?

Answer 1

Scale image from URL. ( scale reference )

import pygtk
pygtk.require('2.0')
import gtk
import urllib2

class MainWin:

    def destroy(self, widget, data=None):
        print "destroy signal occurred"
        gtk.main_quit()

    def __init__(self):
        self.window = gtk.Window(gtk.WINDOW_TOPLEVEL)
        self.window.connect("destroy", self.destroy)
        self.window.set_border_width(10)
        self.image=gtk.Image()

        self.response=urllib2.urlopen(
            'http://192.168.1.11/video/1024x768.jpeg')

        self.loader=gtk.gdk.PixbufLoader()         
        self.loader.set_size(200, 100)   
        #### works but throwing: glib.GError: Unrecognized image file format       
        self.loader.write(self.response.read())
        self.loader.close()
        self.image.set_from_pixbuf(self.loader.get_pixbuf())

        self.window.add(self.image)
        self.image.show()


        self.window.show()

    def main(self):
        gtk.main()

if __name__ == "__main__":
    MainWin().main()

*EDIT: (work out fix) *

try:
  self.loader=gtk.gdk.PixbufLoader()         
  self.loader.set_size(200, 100)   

            # ignore tihs: 
            #  glib.GError: Unrecognized image file format       

  self.loader.write(self.response.read())
  self.loader.close()
  self.image.set_from_pixbuf(self.loader.get_pixbuf())

except Exception, err:
  print err
  pass

Answer 2

anyone doing this in C. This is how it's done

//Assuming you already loaded the file and saved the filename //GTK_IMAGE(image) is the container used to display the image

GdkPixbuf *pb;

pb = gdk_pixbuf_new_from_file(file_name, NULL);
pb = gdk_pixbuf_scale_simple(pb,700,700,GDK_INTERP_BILINEAR);
            gtk_image_set_from_pixbuf(GTK_IMAGE(image), pb);

Answer 3

It might be more effective to simply scale them before loading. I especially think so since I use these functions to load in 96x96 thumbnails from sometimes very large JPEGs, still very fast.

gtk.gdk.pixbuf_new_from_file_at_scale(..)
gtk.gdk.pixbuf_new_from_file_at_size(..)

Answer 4

actually when we use gdk_pixbuf_scale_simple(pb,700,700,GDK_INTERP_BILINEAR); this function causes memory leakage (If we monitor task manager the memory requirement goes on increasing till it kills the process) when used with a timer event. How to solve that

Answer 5

Load the image from a file using gtk.gdk.Pixbuf for that:

import gtk
pixbuf = gtk.gdk.pixbuf_new_from_file('/path/to/the/image.png')

then scale it:

pixbuf = pixbuf.scale_simple(width, height, gtk.gdk.INTERP_BILINEAR)

Then, if you want use it in a gtk.Image, crate the widget and set the image from the pixbuf.

image = gtk.Image()
image.set_from_pixbuf(pixbuf)

Or maybe in a direct way:

image = gtk.image_new_from_pixbuf(pixbuf)

Answer 6

Just FYI, here is a solution which scales the image based on window size (Implying you are implementing this in a class which extends GtkWindow).

let [width, height] = this.get_size(); // Get size of GtkWindow
this._image = new GtkImage();          
let pixbuf = GdkPixbuf.Pixbuf.new_from_file_at_scale(filePath,width,height,true);
this._image.set_from_pixbuf(pixbuf);