Graphical Interchange Format (GIF) is one of the most widely used image formats on the web.
GIF is a bitmap image format that was introduced by CompuServe in 1987 and has since come into widespread usage on the World Wide Web due to its wide support and portability. GIF images are compressed using the Lempel-Ziv-Welch (LZW) lossless data compression technique to reduce the file size without degrading the visual quality.
GIF files start with a fixed-length header ("GIF87a" or "GIF89a") giving the version, followed by a fixed-length Logical Screen Descriptor giving the size and other characteristics of the canvas. The screen descriptor may also specify the presence and size of a Global Color Table, which follows next if present.
Thereafter, the file is divided into segments, each introduced by a 1-byte sentinel:
An image (introduced by 0x2C, a comma ',')
An extension block (introduced by 0x21, an exclamation point '!')
The trailer (a single byte of value 0x3B, a semi-colon ';'), which should be the last byte of the file.
This structure allows the file to be parsed even if not all parts are understood. A GIF marked 87a may contain extension blocks; the intent is that a decoder can read and display the file without the features covered in extensions it doesn't understand.
A GIF, or Graphics Interchange Format is a digital image format that was introduced in 1987. A GIF can be animated or created with a transparent background. With the transparent background, when the image is placed on a webpage, the webpage background shows through the transparent areas on the GIF. Up until the mid-1990s, many editing software programs would not edit or create GIF files, due to licensing restrictions. Now that pertinent patents have expired, it is possible to create GIF files by converting other digital images, such as a JPEG, using graphic software programs.
Create a JPEG digital image using an existing photograph. Lay the photograph on the scanner glass, and press the scan button. Follow the scan wizard that appears on the computer monitor, and save the digital image you are creating to your computer's hard drive to convert to a GIF.
Capture a JPEG digital image using a digital camera, instead of scanning an existing photograph. After you take the pictures, save the digital image on your computer's hard drive to convert to a GIF.
Open the digital image that you created in Step 1 or 2 in a graphic editing program, such as Adobe's Photoshop. Typically, this involves clicking on File in the menu, and then Open in the drop down menu. This will show a new menu with the files on your computer. Find the file you wish to convert to a GIF, and click to open.
Save the image by using the Save as instead of Save command. In Photoshop this command is under File, at the top menu bar.
Choose the new file format by clicking on the drop down menu next to Format. Save the file as a GIF format. After this is done, you will have two digital images of the picture on your computer, one as a JPEG, and the other as a GIF.
GIF files can be opened with various software programs. Open Office and QuickTime Player are two programs you can use to open GIF files.
1 Download and install Open Office.
2 Open the Open Office you have installed.
3 Click File and Select Open.
4 Find out the GIF file you want to open from the appearing window. Choose the file and click Open. The GIF file will be opened in the middle of the window.
1 Download and install the free version of QuickTime Player.
2 Open QuickTime Player.
3 Click File and select Open.
4 Find out the GIF file you want to open from the appearing window. Choose the file and click “Open.” The GIF file will be opened in the middle of the window.
5 Click Play and the GIF file will begin to play.
Converting JPG to GIF is very easy with Image Converter Plus. In Windows Explorer, select a JPG image and click your right mouse button. In the context menu, select Convert to submenu and click Custom convert line.
The list will already contain images selected from Windows Explorer.
To add other files, press Add image button and select some more files in JPG format to be converted to GIF. Select GIF format as target format.
Expand Save images in GIF format group and adjust any needed settings. Available colors are from 2 to 256 colors. Besides color depth, you can also select conversion type:
separate file - all images, single-page as well as multipage, will be saved as separate single-page files.
multipage file - all converted images will be included into one separate file. Page numbers are assigned according to the file list.
as is - all images will be saved according to the structure of source files.
add pages to file - converted images are added to the specified file. If the file doesn't exist, it will be created.
more>> link expands to a professional set of GIF parameters. You won't need this section for daily usage:
- Color quantization reduces the number of distinct colors used in an image while preserving visual image quality.
- Dither is a form of noise, or 'erroneous' signal or data which is added to sample data to minimize quantization error.
Interlacing is a method of encoding a bitmap image. When the image is received partially (especially over a slow communications link), a degraded copy of the entire image is displayed to the user, so that he may decide whether to download the whole image or abort the transmission.
Interlacing is supported by the following formats: GIF stores the lines in the order 0, 8, 16, ..., 4, 12, ..., 2, 6, 10, 14, ..., 1, 3, 5, 7, 9, ....
Press Start to begin conversion.
gifninja is a website that lets you create animated gifs quickly and easily. You can either create an animated gif from individual images or by uploading a video. gifninja also provides you with a nice utility to split an animated gif into separate images.
Convert video to animated GIF
To convert a video to an animated gif, you first need to make sure that you make the video as short as possible. You can do this with one of many online video editing tools or with Windows Movie Maker (if you are on Windows of course). According to gifninja, the video file has to be about 4 seconds long, so you should try to shorten it to about that length.
Once you’ve edited your movie and cut it down to size, visit the page to convert your video to gif. Click the Browse button, navigate to where your video file is, and select it. If you wish, you can make your picture available to the public and available to be rated. Then just click on make my gif!.
Make animated GIF from images
If you have a series of images you wish to animate, you can make an animated gif from images. You can upload the files individually (up to five) or you can zip them up and upload them in a single file. If you choose to upload them as a zip, you will have to append numbers to the filenames in the sequence of the animation (car1.jpg, car2.jpg, car3.jpg, etc…).
Selecting the file(s) to upload is very much the same as uploading a video. However, there is an additional option to set the speed of the animation. There is a preview of an animated dog that demonstrates the selected speed. But don’t worry, if you’re not happy with the speed of the animation after you’ve uploaded it, you can adjust it later.
After you click the make my gif! button, you are taken to a preview page. The preview page allows you to keep the image as it is, adjust the speed, or start all over again. Once you have the animation set to the desired speed, click Yes – it’s fantastic! to proceed to the next step.
After you’ve selected the desired speed for your animation, you select the filename for your animated gif. Again, you can make the image publicly available if you wish. You can also enter the filename for the image as well as tags to help other people find your image. Once you have everything set the way you want, click the Save gif button.
gifninja also has a cool feature to split animated images into separate images. Just upload the file and click the split my gif! button. The individual images will appear right on the page. You can also download all the images at once with a zip file generated by gifninja.