Extracting BMP frames from an AVI files using AVIedit
Often we all need to show someone few pictures to illustrate
things, or we may prefer to e-mail just small pictures instead of
sending an entire avi file. Unfortunately today internet connections
are sometimes too slow to transfer avi files - so obviously we
need some way to get a series of images from such a file.
Unlike standard Windows mediaplayer, AVIedit offers you one-frame
precision control over the process. Why it is important ? When you need
to get a snapshot
of a live video source, it is often too hard to choose the
moment to take a picture. Having the same video clip in the avi file
format, you can scroll back and forth along the clip to see really the
best time for snapshot as long as you need.
The basic image export routine looks very simple.
That's all. But where is the file ? What image format it uses ?
Lets see what we could tune up in AVIedit...
Open an AVI file
Click inside the desired frame
Use Edit/Export menu item to get this frame as a separate image file
To assign a directory where to put the extracted frames, use Options/Preferences
menu item. Then select Directories tab. AVIedit allows you to save all files
together, also it allows you to enter a separate folder name for each
group of files you would like to use. This time we need to check only Export
category. By default AVIedit starts with C:\ and you can override this. Say,
if you really like My Pictures directory assigned by Microsoft, you can
use it :)
Now we will see what format we exported to. AVIedit supports several file
formats and you can decide what is the best for you using the Export tab.
Here you see BMP, JPEG, GIF and TARGA formats. BMP does not use image
compression techniques, so often it offers you the best picture quality.
But its file size is too big.
To export photographic images, for web
design or presentations, you probably will use JPEG format. AVIedit allows
you to set quality factor (1..100), the higher is the value, the better is
image quality. For some special cases you may wish to use grayscale format.
Also there is an option for progressive encoding. It is useful to allow your
web site visitors to see a preview quality image very quickly, without having
to wait until picture download finished.
To save line art images you may prefer GIF output format. AVIedit allows
you to use different # of bits and number of colors per picture. The lesser
is number of colors, the smaller is resulting file - but the quality may
TARGA images are not too common case today - but this is native format
for many animation packages and 3D modelling tools. It offers the same quality
and file size as BMP.
Many users would like to change default file names used by AVIedit. It is easy
enough. Place the mouse arrow over the Template edit box to see tooltip window.
There are few predefined symbols that AVIedit will treat in a special way.
This template allows you to keep frame numbers, or just mark the frames with
date to keep them in order.
%T will be substituted with current time
%D will be substituted with today date
%N whole number that incremented automatically
%F source avi file frame number
Do you think there is nothing more to know about ? You missed all filters :)
For example, to despeckle an image you might try Median filter built-in
into AVIedit. Here is step-by-step instruction, it does not include normal
Now, all the images you export will pass through a filter. The same way
you can improve the image sharpness and contrast, fix the color
distribution and brightness. This is important because many in-door
made videos are color shifted (mainly to red colors) and have wrong
Use Process/Filter to see main Filter dialog box
Check export and preview options in the group marked What to filter
Choose Matrix filter from left list of available filters
Double-click filter name, or hit >> button
New dialog box pops up. Select Median Filter 1 from dropdown list
Click Ok to confirm Median Filter addition to the current list of
Click Proof button to see (preview) the effect
Click Ok to confirm apply filters to the video clip
Some additional information you can find in a help file. I wish you
good luck playing with extraction bitmaps from avi clips.
Copyright 2000, 2009 AM Software