[Matplotlib-users] slow rendering of 2K images using Animation_blit_tk.py - bis

[Auré G. <aur...@ya...>]

Dear all,

I recently cried for help (see below) but sadly didn't get any answer... This problem is really a bottleneck for me and if I must find a solution... Can anyone PLEAAAAAAAAASE point me in the right direction ? 

I recently bumped into a problem while trying to display
imshow images (2048x2048 pix) in a GUI based on TkAgg (matplotib0.91.2,
python 2..4..4, numpy1.0.4). In brief, building the image with imshow is
Ok, but the call to show() or draw() takes about 1.2 s on my system
(XP, 2.8Ghz, 2Go ram). After reading a lot of posts and trying out a
few things, I turned to the Animation_blit_tk.py example and modified
it accordingly (code attached below). In the end, the display is still
not much faster using this method (still in the order of 1.2 s as
indicated by the result below).
Could any one tel me whether I'm doing something wrong ? 

As
far as I understand, at least in my Tk GUI, the limiting step using the
ImageTk.FigureCanvasTkAgg is the call to draw() or draw_artist(). I
read some comments from John regarding TkAgg being slow in some cases
but couldn't find a definite answer.

Any hint would be much appreciated....

Cheers,

Aure


--------
# For detailed comments on animation and the techniqes used here, see
# the wiki entry http://www.scipy.org/Cookbook/Matplotlib/Animations

import matplotlib
matplotlib.use('TkAgg')

import sys
import pylab as p
#import matplotlib.numerix as nx
import time

from FileUtils10 import fileHandling

# for profiling
tstart = time.time()
tprevious = time.time()

fnamelist = ['fname1','fname2','fname3']

ax = p.subplot(111)
canvas = ax.figure.canvas

print 't1 ',time.time()-tprevious
tprevious = time.time()

# create the initial line
dataarr = fileHandling(fnamelist[0]).readSpecial()
#print dataarr.dtype        =>   numpy dtype uint16
#dataarr = dataarr.astype('uint8')
print 't2 ',time.time()-tprevious
tprevious = time.time()

image = p.imshow(dataarr, animated=True)
print 't3 ',time.time()-tprevious
tprevious = time.time()

def run(*args):
    tprevious = time.time()
    background = canvas.copy_from_bbox(ax.bbox)
    print 't4 ',time.time()-tprevious
    tprevious = time.time()
    while 1:
        #print fnamelist[run.cnt]
        # restore the clean slate background
        canvas.restore_region(background)
        print 't5 ',time.time()-tprevious
        tprevious = time.time()
        # update the data
        dataarr = fileHandling(fnamelist[run.cnt]).readSpecial()
        print 't6 ',time.time()-tprevious
        tprevious = time.time()
        image.set_data(dataarr)
        print 't7 ',time.time()-tprevious
        tprevious = time.time()
        # just draw the animated artist
        ax.draw_artist(image)
        print 't8 ',time.time()-tprevious
        tprevious = time.time()
        # just redraw the axes rectangle
        canvas.blit(ax.bbox)
        print 't9 ',time.time()-tprevious
        tprevious = time.time()

        if fnamelist[run.cnt] == fnamelist[-1]:
            # print the timing info and quit
            print 'total time:' , time.time()-tstart
            print 'FPS:' , 1000./(time.time()-tstart)
            p.close('all')
            sys.exit()

        run.cnt += 1
run.cnt = 0


p.subplots_adjust(left=0.3, bottom=0.3) # check for flipy bugs
p.grid() # to ensure proper background restore
manager = p.get_current_fig_manager()
manager.window.after(100, run)

p.show()


====
Results in:

t1  0.858999967575
t2  0.0320000648499
t3  1.31299996376
t4  0.0
t5  0.0
t6  0.0310001373291
t7  0.0
t8  1.18700003624
t9  0.0160000324249
t5  0.0
t6  0.0469999313354
t7  0.0
t8  1.17200016975
t9  0.0149998664856
t5  0.0
t6  0.047000169754
t7  0.0
t8  1.21899986267
t9  0.0
t5  0.0
t6  0.0460000038147
t7  0.0
t8  1.17199993134
t9  0.0
t5  0.0
t6  0.0469999313354
t7  0.0
t8  1.18700003624
t9  0.0160000324249
total time: 8.75
FPS: 114.285714286