April 10, 2015
When it comes to digitization, so many options are available that it sometimes becomes more time consuming to figure out what image specifications are needed than to actually digitize of the material in question. Let’s take a look at two of the most common file formats and their benefits and trade-offs.
In regards to file formats and image types, we live in a world of three letter acronyms- JPG, TIF, LZW, BMP, RAW, PNG, PDF, GIF, (the list goes on)– so one thing we need to ask ourselves before we decide is, “what will we be using the image for?
If the answer is, “long term preservation” then the traditional answer would be a lossless or uncompressed TIFF file. Around for nearly 30 years, the Tagged Image File Format has garnered a reputation for being a untainted, versatile format—but, in color or even grayscale representation it also has a reputation of being space-hungry, processor demanding and hard drive greedy, especially when it comes to representation of full color. With storage space becoming cheaper, processors becoming more robust and transfer rates becoming faster, the TIFF has become a more acceptable and practical choice for those seeking what is known as “archival image quality”.
From a single TIFF file, multi-faceted editing can be applied and derivatives can be easily created without significant overall loss in image quality. Image compression algorithms and schemes such as LZW and CCITT Group 4 have been used in the past to package up TIFF files into nice little digital suitcases in order to shrink file size, but as hard drive space increase and sizes becomes less and less of an issue and rendering options on devices and through applications expand, the multifaceted beauty of what can be achieved through and from an uncompressed full color TIFF file stands alone.
Some folks don’t care about “long term preservation”. For them the word “TIFF” is just a synonym for a petty argument. They simply need a modest file that is easily rendered across a broad spectrum of devices, small enough to be quickly transferred via mobile phone or displayed online and legible enough to give them the information they need. One thing is for sure, the JPEG (JPG) file defines efficiency. Sure it is based off of lossy compression, but that in itself reflects life’s ephemeral nature.
The JPEG seems almost more friendly– more compatible, thus more “human” when compared to the rigid, formal complexity of a 24 bit TIFF file. The best thing about a JPEG may be a result of its most criticized characteristic– that you can compress it down to the smallest file size imaginable and somehow, in such a degraded state, it still contains enough information to remain legible. Sure, we might recall the early days of the internet where a compressed, low resolution JPEG image of several thousand pixels tended to appear as if it had lost its focus– along with acquiring a bad case of digital chickenpox– but with megapixel counts and image resolutions from image capture devices increasing each coming year the amount of compression that can be applied to an image before visual artifacting is observed is quite high. The key to the use of a modern day high resolution JPEG is simple—don’t rely on it as a stable source of multiple derivative files and satisfaction will be guaranteed.