Difference between +map and +remap

[OrangeDog]

The two commands clearly do different things to an image sequence: +map is much faster and +remap gives more accurate colours in the output.
However, there doesn't seem to be any documentation for +map (but it appears in lots of code around the place).

What is different in the way these commands operate?

[fmw42]

I believe at one time -map and -remap were equivalent or at one time -map was deprecated in favor of -remap. Today, -map is no longer a function that works with convert (or if it does it is an older version of -remap). -map is currently used with animate and stream.

see
http://www.imagemagick.org/script/comma ... ns.php#map
http://www.imagemagick.org/script/comma ... .php#remap


Where do you see -map being used with convert in the documentation? It may need updating.

[OrangeDog]

Not in documentation but in my working production code (6.7.9-6)

Code: Select all

convert -dispose Background in-%02d.png[1-50] -set delay 10 -loop 0 -dither FloydSteinberg +map out.gif

No warnings, and different results from +remap or omitting it.
The high speed of +map vs. +remap is desirable, and I was after some clue about what exactly it's doing.

[anthony]

I believe the basic difference is that one dithers to a common color map over ALL the images in the sequence, while the other maps each image individualle

[OrangeDog]

Can you dig out the equivalent of +map's operations using actually documented features so I can switch to those?
Ideally I don't want to have the next person come along and have no way to find out what this command is doing.