Resizing An Animated GIF
The purpose of this guide is to teach you how to take an Animated GIF file, and reduce the size of it.
One of the reasons you might want to reduce the size of the GIF, you have a nice animation you want to use as an avatar on this forum. For the purpose of this tutorial, let's assume the GIF is 100 pixels wide x 100 pixels high. This forum will not support an avatar that is larger than 83 pixels high x 83 pixels wide, so it needs to be resized to work properly.
An animated GIF, is a file made up of layers of images, stacked one on top of the other.
In each layer, the image is a little bit different than the previous image.
So, when each image is "flipped through" at a given speed, the image appears to move, like a flip-book.
This is a rather simplistic explanation, but that's how it basically works.
If you try to use a GIF larger than 83 x 83, the forum's software will reduce it to those dimensions. Since the software doesn't support animation resizing, the first image that makes up the animated file will be resized. It will ignore, and discard, the other images, leaving you with an image that is not animated.
This Tutorial will be broken into 2 parts.
The first part will deal with using Irfanview, to extract the frames of the GIF, then resize and convert them.
The second part will discuss the actual re-compiling, of the extracted frames.
A short Flash presentation is also available for viewing. As there are several steps involved, and the use of 2 programs, I suggest you first read through the tutorial to familiarize yourself with the process, then watch the video,
If you still have question rereading the Tutorial, should answer most of them.
The written Tutorial, will give you a bit more detail about the Resizing operation.
Animated GIF Resizing Video
Tools NeededInstructions: Part 1
- Open Irfanview, click File, and select Open.
- Navigate to the GIF you want to resize, highlight it, and click the Open button.
This will load the file into Irfanview.
- Click Options, and select Extract all frames..., which will seperate the animation into it's individual frames.
This will open the Browse for Folder dialog box.
- Select the folder you want the extracted frames sent to, and click OK.
- Click File again, and select Batch Conversion/Rename...
This will open the Batch conversion dialog box.
- Click the dropdown arrow next to the Look in: box, and navigate to the folder you extracted the GIF frames to.
Use the dropdown arrow next to the Files of type: box, to make sure BMP/DIB/RLE is selected.
- Highlight the extracted files, and click the Add button.
This will add the files to the Input files: list.
- In the Output directory: section, click the Browse button, which will open the Browse for Folders dialog box, and navigate to where you want the converted files saved.
- In the Work as: section, put a tick next to Batch conversion.
- In the Batch conversion settings: section, under Output format:, use the dropdown arrow to select GIF.
- Click the Options button.
This will open the JPEG/GIF save options dialog box.
In the GIF section, the only thing that should be checked is, Save interlaced.
Click the OK button.
- On the right, put a check in the Use advanced options box.
This will activate the Set advanced options button.
- Click the Set advanced options button.
This will open the Settings for all images: dialog box.
- This is a list of what should be checked/ticked in this dialog box:
Set new size:
Set long side to: (type 83 in the box, as shown)
Preserve aspect ratio (proportional)
Use Resample function (better quality)
If anything else is checked, remove the checks/ticks, then click the OK button.
These settings will remain the same, everytime you open Irfanview, unless you change them, so if you have several GIF's to convert, you won't have to reset them.
- Click the Start button.
- You'll see the files being processed.
When it's finished, click the Exit button.
- Close Irfanview.
That wasn't too hard, was it?
Now, on to the making of the animated GIF.
Edited by tg1911, 16 November 2006 - 08:46 PM.