Smart phones has paved the way for people to take pictures without the hassle of bringing a bulky camera. And as the competition for the best camera phone intensifies, more and more mobile companies are improving the features of their cameras, particularly the resolution.
However, only little attention has been put into the format of the picture. Most people have no idea that it plays a big role in the quality of the image. Thus, if you choose the wrong format, your large resolution and refined pixels might be useless after all. But what are the available image types for you to use?
To shed light on this matter, listed below are the two most popular image formats, and the characteristics of each type (JPG and PNG).
Joint Photographic Experts Group (JPEG or JPG)
Considered as one of the earliest form of file format for photos, the “JPG” was developed by the Joint Photographic Experts Group, whose shortened form is JPG, hence the extension name. It was created mainly for the purpose that all professional photographers will have a standard for their digital images.
In a JPG file, the data is reduced into a blocks of pixels, which are called “tiles”. Similar to a ZIP file where file redundancies are purged to compress data, saving your picture in a JPG format will compress several pixels into a tile, with a possible compression ratio of 2:1 to 100:1. However, a JPG file saves these tiles permanently, leading to pixel loss. As such, when you zoom closely on a JPG file, you will see “pixilation” in the picture.
JPG was easily embraced by users because of the lousy internet speed in the 1990s. Most people during that time were on dial-up, and so a small file size is practical if you just want to upload and share your pictures. At the same time, more people will be able to download your image if it is less than a megabyte in size.
If you’re going to save artworks digitally, JPG is not the best format to use. Its nature of compression will alter the appearance of a photo, no matter how high the quality of a JPG is. Moreover, it is not recommended to be used for typography and crisp photographs, as the edges will most likely be blurred out. Most importantly, if you save a JPG image multiple times, that would be tantamount to several compressions, and will lead to severe quality degradation.
But then again, if you’re concerned with sharing your images, JPG is a great way to go as most people can easily download your picture.
Portable Network Graphics (PNG)
Another widely-used format in photography is the Portable Network Graphics or PNG for short. Unlike the JPG which sacrifices data loss for compression, a PNG file uses a lossless LZW algorithm to compress data. A lossless data meant that the quality of the photo is preserved, despite the compression.
Another great thing in a PNG format is that you can use transparency when savings images. This makes it ideal for internet graphics, as the transparency gives pictures a modern vibe. Take the case of the Windows Vista platform and its Aero desktop. A key characteristic in the Aero desktop’s modern appearance is its transparency, which is a stark contrast with the Windows XP’s gradients. Until now the JPG doesn’t support such feature, which gives the PNG an edge over the other image type.
Since a PNG image doesn’t forgo much of the data, it usually has a bigger file size compared to the JPG. While you can reproduce your pictures in the highest quality (pixel-by-pixel), this is at the expense of your physical memory. Therefore, it is not best for those who wanted to conserve disk space.
The large file size also makes it less desirable to be shared via the internet. Fortunately, you can save a PNG in an interlaced setup. Interlace refers to the method on how an image is rendered on a webpage. In an ordinary, non-interlaced image, the webpage loads the picture from top to bottom. On the contrary, parts of the interlaced image will be loaded simultaneously, albeit in low-quality. As such, you can get a “feel” of the whole image before its full resolution can be downloaded.
Looking at both the advantages and disadvantages of each image type, you can deduce that there’s actually no optimal format for saving photos. However, you can choose to save your image depending on its intended use. JPG is still the best format if the picture is expected to be downloaded by others, while PNG is ideal for preserving the quality of files and for those images needing transparency.
This was a guest article from Jake Bollingston.