[SciPy-User] How to draw an image in fltk from numpy array?
Andy Fraser
afraser at lanl.gov
Tue Dec 15 14:48:19 EST 2009
Users,
I have used scipy for a few years. Now I want to write a GUI in fltk
to look at intermediate results of image manipulations, and I'm having
trouble getting started. I get segmentation faults.
I started with the "hello world" example at
http://pyfltk.sourceforge.net/examples.php
As a next step, I tried to display a small random image. Following
the code for the fltk backend in matplotlib, I wrote the code I'll
include below. When I run the code, it produces:
->python GUI.py
before fltk.fl_draw_image
Segmentation fault
I suspect that argument "bits.data" is an inappropriate argument of
fltk.fl_draw_image. Does anyone have a different idea, or advice on
how to construct a correct argument?
Andy
#file GUI.py
import sys, fltk, numpy
W = 180
H = 90
D = 3
X = 5
Y = 200
bits = numpy.empty( (W,H,3), numpy.uint8)
# class derived from /usr/share/pyshared/matplotlib/backends/backend_fltkagg.py
class FltkCanvas(fltk.Fl_Widget):
def __init__(self,x,y,w,h):
fltk.Fl_Widget.__init__(self, 0, 0, w, h, "canvas")
self._oldsize=(None,None)
self._draw_overlay = False
self._button = None
self._key = None
def draw(self):
newsize=(self.w(),self.h())
if(self._oldsize !=newsize):
self._oldsize =newsize
print 'before fltk.fl_draw_image'
fltk.fl_draw_image(bits.data,0,0,int(W),int(H),3,0)
print 'did fltk.fl_draw_image'
self.redraw()
def theCancelButtonCallback(ptr):
sys.exit(0)
window = fltk.Fl_Window(100,100,200,400)
canvas = FltkCanvas(X,Y,W,H)
canvas.draw()
window.end()
window.show(len(sys.argv), sys.argv)
fltk.Fl.run()
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