Accordian colorbars on animations.

[wstraka]

So, when I try to make a animated GIF using a bundle in a script, I get an accordion type movement of the colorbar, no matter what method I use.

In the case of goese_11bt_mov_colorbar_in_bundle.gif, I used a bundle where I stored the colorbar inside of it. The animated GIF was made using the following command:

writeMovie("/data/Personal/wstraka/Mc_V_scripts/goese_11bt_mov_colorbar_in_bundle.gif")

In the case of goese_11bt_mov.gif, the bundle used did not have the colorbar stored in it. The colorbar was added at the time the movie was made in the script using the following command:

writeMovie("/data/Personal/wstraka/Mc_V_scripts/goese_11bt_mov.gif", "colorbar width=300 height=20 anchor=UM place=UM,0,20 showlines=true tickmarks=5 color=white showunit=true linecolor=white")

One would think that, given that the range of the data is the same for every image and the colorbar used is the same for every image, that you would not have this accordion type shift inside the colorbar.

[Rick]

Hi William,

How did you load the images - individually or all at once (i.e., 5 most recent)?

Rick

[wstraka]

All at once. But I've had the same issue even when I am in a McV session (i.e. not via a script) and saved an animation that way.

[wstraka]

Actually, it appears it is an issue with the storage as an animated GIF

Animated GIF attached. MOV file up at: ftp://ftp.ssec.wisc.edu/pub/ssec/wstrak ... bt_mov.mov

[beckys]

What OS version is this machine running?

[wstraka]

Why a RHEL6 machine. And no, this isn't Mc-X, but I suspect it is a problem cross-OS

[tomw]

This is an artifact of the animated GIF encoding. Remember, GIFs can only have 256 colors, and I believe in the encoder used here, each frame is analyzed to create it's own color table; hence, if you have more than 256 colors represented in the original image, some compromises will have to be made...

[wstraka]

Wouldn't that affect the image itself?

As for the colorbar itself, it has only 256 colors, so the question about GIF encoding should be mute, I think, given that I am using the maximum number of colors allowed for a GIF.

BTW, since Mc-V can save PNGs, why not save the images as PNGs and the animate that?

[tomw]

You might have more "colors" in the colorbar than the image, and if compromises have to take place, it would be with the colors that have the fewest number of occurrences in the "scene".

Regarding animating PNGs -- sure...you can save this for AniS/FlAniS animations...there is a menu option for that which creates the HTML and you can put the .png images into the same directory.

The advantage of animated GIFs is that it is just one file and all browsers know how to animate them with no additional plug-in required....