What is a JPEG?



JPEG (pronounced "jay-peg") is a royalty free image format that was created by a committee known as the Joint Photographics Expert Group. It was designed to compress photographic images so that they take up much less space.

However, the JPEG format is a "lossy" one. This means that when a JPEG image is decompressed it is not quite the same as the original image. But don't worry as this is not a big issue because it is possible to set the quality level that should be used for an image.

At a high quality level the human eye will not be able to distinguish the differences and you will still get a very useful space saving with about a 10:1 compression ratio – ie an image will be compressed to one tenth of their original size.

At medium quality levels you will be able to spot slight differences (known as "compression artifacts") but these should not normally detract from the image and you will get a compression ratio of around 20:1.

Of course lower quality levels are available that allow a compression ratio of 100:1 to be achieved but the resultant images will look very "blocky".

JPEG is probably the most popular image format in use thanks to its high image quality and low space requirements. It is widely used on the Internet and as the storage format for photographs taken with most digital cameras.

What is a PDF?

PDF is a royalty free general purpose Portable Document Format created by Adobe Systems. It is ideal for storing and displaying fixed layout documents in a device and resolution independent way.

What this means is that a PDF document will be displayed in the same way no matter what device it is viewed on – whether it is on a PC with a large screen or on a small personal organizer.

It is also important to note that a PDF document can be printed to any printer and the printed output should look exactly the same (or at least as close as possible subject to any limitations that the printer might have).

Because of the benefits outlined above, PDF is widely used on the Internet and is extensively used within the print industry where printing accuracy is a must.

Why should you convert JPEG images into PDF documents?

While JPEG images are easy to use there are some limitations with them that make PDF documents a more attractive way of distributing images.

First of all if you want to display and print a JPEG image then what you see on screen is not necessarily what you get printed! This is because the screen resolution is likely to be very different to the printer resolution and the application that is used to display the image on screen cannot always take this into account.

However, using a PDF document that contains the same image, not only is the image displayed at the correct size on screen but you get a perfect printed copy.

If you want to store or distribute a number of images together then it makes more sense to put them into a single PDF file. Especially if you want to send them via email (you only have to include one file attachment and the recipient can open the PDF document and scroll through all of the images straight away) or display them on a web site (you only need to link to one file not lots of them).

With a PDF document you can also restrict what can be done with it – you may only want authorised users to be able to view the document in which case you can password protect it. Or you can prevent a user from editing or printing the document if you only want them to be able to view it on screen.

You can of course do much more with a PDF document, for example, you could create a simple PDF photo album of your images with a built-in slideshow using some fancy page transitions between each image.

How can you convert JPEG images into PDF documents?

While you could use the fully featured and relatively expensive Adobe Acrobat application to convert JPEG images into PDF documents, this can be both time consuming to learn and overly complex if all you want to do is to convert some JPEG images.

There are some free applications available, such as Open Office, but these do not generally allow you the same level of control or automation as dedicated third party tools.

A better solution could be to use a dedicated tool such as one of the "Image to PDF" range of products from Utility Warrior.

There are some other advantages to using a tool that is dedicated to the job of just converting JPEG images into PDF documents – it will probably be cheaper for a start!

Also, these tools will often be much smaller in size as there is no unnecessary code bloat, and this can also mean that they are faster in operation – which can be very important if you have thousands of JPEG images to convert!

Hopefully this brief article will have given you enough grounding to evaluate the solutions that are available to convert your JPEG images into PDF documents to best find one that matches your needs. Happy converting!

Copyright 2007 Adrian Nelson