png to slideshow (gif)

Community matplotlib-users
1

If I have 30 PNGs and i would like to make a slideshow or an animated gif what is the best way to do this? Can matplotlib do this?

···

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2

There is an example showing how to create an MPEG-4 movie here:

http://matplotlib.sourceforge.net/examples/animation/movie_demo.html

Creating an animated gif would just be a matter of using the correct third-party tool that can combine a set of image frames.

Mike

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________________________________________
From: Rita [rmorgan466@...287...]
Sent: Friday, March 18, 2011 7:49 AM
To: matplotlib-users@lists.sourceforge.net
Subject: [Matplotlib-users] png to slideshow (gif)

If I have 30 PNGs and i would like to make a slideshow or an animated gif what is the best way to do this? Can matplotlib do this?

--
--- Get your facts first, then you can distort them as you please.--

3

There is an example showing how to create an MPEG-4 movie here:

http://matplotlib.sourceforge.net/examples/animation/movie_demo.html

Creating an animated gif would just be a matter of using the correct third-party tool that can combine a set of image frames.

For example, gifsicle or ImageMagick.

Eric

···

On 03/18/2011 03:56 AM, Michael Droettboom wrote:

Mike

________________________________________
From: Rita [rmorgan466@...287...]
Sent: Friday, March 18, 2011 7:49 AM
To: matplotlib-users@lists.sourceforge.net
Subject: [Matplotlib-users] png to slideshow (gif)

If I have 30 PNGs and i would like to make a slideshow or an animated gif what is the best way to do this? Can matplotlib do this?

--
--- Get your facts first, then you can distort them as you please.--

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4

Dear matplotlib users,

The following very simple script generate an explosion of ram memory :

from numpy import *
import pylab as pl

while 1:
   data = random.random((512,512))
   pl.imshow(data)

How is it possible to loop over imshow, without having this problem ?

Thanks in advance,

yves

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   1290 Sauverny e-mail : Yves.Revaz@...2003...
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5

Dear matplotlib users,

The following very simple script generate an explosion of ram memory :

from numpy import *
import pylab as pl

while 1:
    data = random.random((512,512))
    pl.imshow(data)

Try adding "pl.clf()" or "pl.cla().
Without that, each call to imshow is adding an image without deleting the previous one.

Eric

···

On 03/18/2011 11:15 AM, Yves Revaz wrote:

How is it possible to loop over imshow, without having this problem ?

Thanks in advance,

yves

6

I have used ffmpeg in the past with some success. It generates mpeg 4 video files, but maybe that's OK for you?

The only requirement is that your files are named on the format file_0000.png file_0001.png ...
See examples below.

Cheers
Paul.

···

On 18. mars 2011, at 12.49, Rita wrote:

If I have 30 PNGs and i would like to make a slideshow or an animated gif what is the best way to do this? Can matplotlib do this?

+++++++++++++++++++++++++

ffmpeg -qscale 5 -r 20 -b 9600 -i img%04d.png movie.mp4
ffmpeg -qscale 5 -r 20 -i img%04d.png movie.mp4

# The options are
#
# * -qscale 5 … define fixed video quantizer scale (VBR) where 1 is the best and 31 the worst. Since mpeg/jpeg has problems to compress line graphics it’s a good idea to set this variable close to 1. You get a big movie file, but otherwise the movie doesn’t look, well, that good.
# * -r … framerate
# * -b … video bitrate
# * -i input files, %04d says that we have four numbers in the filename where the number is filled with zeros left of it.
# * movie.mp4 is the filename, the extension says that it is a quicktime movie. You can also create a Macromedia Flash movie by using the .flv extension.
# Info from: Create a movie file from single image files (png, jpegs) | miscellaneous.debris
# Note that the images have to be numbered 1,2,3,... not (for example) 2, 4, 6... or 10, 20, 30...