A Guide to Image File Formats and Image
Compression
Are you confused by
the various image file formats used in digital photography? Image editors like
Adobe Photoshop CS, Ulead PhotoImpact and Paint Shop Pro support many, many
image formats.
It is sometimes very
confusing – you’re not sure when to use which image format.
This article will try
to clear that up, introducing the main image formats used in digital
photography and when to use them.
The JPEG File Format
The JPEG file format is the most popular image file format in the world today.
It’s very popular because it saves a lot of hard drive space. A high-resolution
picture with 25MB of color information can be shrunk down to about 1MB using
JPEG compression.
The downside of JPEG? Well, bear in mind that each time you edit and save a JPEG
image, you’re losing image quality. Some photographers who want maximum image
quality will avoid using JPEG totally.
The TIFF File
Format
The TIFF image format is the reverse of the JPEG format. A TIFF image consumes a
huge amount of disk space. We’re talking about 6MB to 18MB for a typical TIFF
images. That’ll eat up your hard disk in no time. However, TIFF images are of
extremely high quality – there is no data discarded when you work with or save a
TIFF file.
The RAW File
Format
The RAW image format offers you the purest possible pictures, ready for your
editing on the computer. The RAW format is proprietary and each manufacturer
(Canon, Nikon, Olympus and the like) use their own version. When you take a
picture in RAW format, the camera does nothing to the photo. There is no
adjustment at all – the picture is purely what is recorded by the image sensor
on the camera.
When to Use Which
Format
How do you know which format to use, and when? Well, my first piece of advice is
to avoid the RAW format. Unless you’re a very experienced photographer who wants
to manually correct all your photos, the RAW is not a very good choice.
The next question, inevitably, is whether to use JPEG or TIFF. Personally, I use
JPEG most of the time. The simple reason is that you can choose the amount of
compression used in a JPEG image. In Paint Shop Pro, for example, you can choose
File > Save As, then select the JPEG compression factor under the
JPEG options dialog box. Select a low compression setting and you get a higher
quality JPEG, select a higher compression setting and you get a lower quality
JPEG.
Conclusion
As you can see, there are many image formats used for digital photography. These
image formats are typically JPEG, TIFF and RAW. It’s important to understand
these formats so that you can select the appropriate format to use under
different situations.
Touch Up
Your Photos Easily
Ulead PhotoImpact is a great photo editor that does its job
- yet doesn't burn a hole in your pocket. I've used this program for a long time
and it has never let me down.
PhotoImpact has all the usual tools you expect in a photo editor, contained within a smart, uncluttered user interface. It's definitely worth a try, especially if you don't want to invest in expensive commercial editors like Adobe Photoshop CS.
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