Exporting images as .avi

Question

Here's a list of images:

images = Table[ExampleData[i], {i, ExampleData["TestImage"]}];

And according to the reference "Export exports a list of graphics, images, or arbitrary expressions, taking each element to be an animation frame." This is on the reference page for .avi. However,

Export["animation.avi", images]

causes this:

Export::errelem: "The Export element !(\"ImageList\") contains a malformed data structure and could not be exported to !(\"AVI\") format."

What's the problem?

(Export["film.avi", ListAnimate[images]] works, but I want to know why the above doesn't work...)

In light of Sjore's answer it is interesting why Export["film.avi", ListAnimate[images]] does work? — Ajasja, May 15 '12 at 20:42
Hm... perhaps not. What happens when we export ListAnimate? Basically it's like exporting screenshots of a manipulate-window. All these screenshots have the same size, color channels and so on. — C. E., May 15 '12 at 22:01

Sjoerd C. de Vries · Accepted Answer · 2012-05-15T20:28:16.143

9

The images have different color spaces, dimensions and image channels. How would you make a movie from that?

ImageColorSpace /@ images // Union

(*  ==> {"Grayscale", "RGB"}   *)

ImageDimensions /@ images // Union

(*  ==> {{256, 256}, {512, 512}, {1024, 1024}}  *)

ImageChannels /@ images // Union

(*   ==> {1, 3}  *)

You'd have to convert them all to the same format.

images2 =  ImageResize[ColorConvert[#, "Grayscale"], {256, 256}] & /@ images

will do just that. You can now export it:

Export["animation.avi", images2, "FrameRate" -> 1]

enter image description here

edited May 15 '12 at 20:28

answered May 15 '12 at 20:22

Sjoerd C. de Vries

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It might be worth adding a note that one can use ConformImages to do the conversion in version 10 – Simon Woods Sep 21 '14 at 10:12
A powerful function, indeed. Good find! – Sjoerd C. de Vries Sep 21 '14 at 12:35

score 4 · Answer 2 · answered May 15 '12 at 20:11

I would guess this is because the images are all of different sizes. For a concrete answer about this, contact technical support at support@wolfram.com with your license number.

In meantime you can create the animation using a Manipulate:

Export["animation.avi", 
 Manipulate[images[[i]], {i, 1, Length@images, 1}]]

Exporting images as .avi

2 Answers2

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