JPEG Compression or PNG – What Is Preferred and Why?
While you are reading this, let’s just admit that we prefer viewing images more than we like reading the text. What a writer may explain in thousands of words, an artist can depict in one picture. It all boils down to the fact: it better be one image than thousands of words. But choosing an image isn’t as easy as it sounds.
We are moving towards a visual future. There are videos, infographics, 360 images, everywhere. Website design is more visual than ever, and finding the right image is imperative to building your brand image. However, one of the basic challenges of choosing the right image is choosing the right format. And speaking of formats, there is no denying the fact that JPEG and PNG are two of the best.
If you haven’t noticed, JPEG and PNG images are virtually similar. You can hardly tell the difference. In order to understand which one is better for your task, you need to understand how they are different and what purpose each of them serves better.
It Is All About Compression
Image compression is an important part of digital imaging. Our eyes are amazing when it comes to capturing resolution but digital sensors are able to capture much more than that. The problem is higher resolution means huge image size.
So, compression is all about reducing the size of an image to digitally store it on a device. For decades, techies have been trying to improve the compression techniques to ensure high-quality images that do not take a lot of space. Smaller size makes it easy to transfer and store. Also, when used on a website, the size of an image can affect the speed and performance of the site.
Now, we have different formats because of different compression techniques. There are two kinds of image compression techniques: the lossy compression and the lossless compression. As evident by the name, lossy compression involves some loss of data while lossless involves no loss of data during compression. Naturally, loss of data means loss of pixels and that can affect the quality to a certain extent. However, it doesn’t mean lossy compression always mean bad quality. Since our eye can’t even see so many details, there is no harm in losing some of that detail.
Both JPEG and PNG use a different compression technique. Let’s discuss each of them separately.
JPEG Compression
JPEG stands for Joint Photographic Experts Group. It is the most commonly used format in digital photography. If you have ever got your event covered by a pro photographer, check the format of the digital images they return. It is a JPEG. It has a 10:1 compression ratio, which means every 10MB is reduced to 1MB.
The downside is that it is a “lossy” compression technique. Some information from the original image is discarded to optimize the size without a significant difference in the image quality. Every time the image is edited and saved, there is more loss of pixels and quality.
JPEG manages to retain the quality because of its utilization of the DCT algorithm. The algorithm determines the closely matching pixels in the image and merges them together. The change is barely visible and the quality seems similar to that of the original image.
This is why it is preferred for print purposes. Event photography, brochures, magazines – JPEG stands as a winner in these categories. However, it isn’t always a winner in graphic design as illustrations can lose their sharpness due to antialiasing in JPEG.
PNG Compression
PNG stands for Portable Network Graphics. The major difference is that it is a lossless file format. This means there is no loss of quality during compression. The sharpness is retained and therefore it is the format preferred for the web.
Unlike JPEG, PNG utilizes the LZW compression algorithm. It isn’t as simple as the DCT. Instead of matching pixels, LZW involves matching long strings of bits and assigning short-codes within the image file. The size of the image is marginally reduced but the quality is maintained.
The biggest advantage of using PNG is that the quality remains the same no matter how many times the image is opened and saved. High-contrast images and images with texts retain the same contrast and sharpness.
That is not all. There is one more feature of PNG that makes it more useful for the web. Unlike JPEG, PNG supports transparency. You can have the image of the object with no background. It makes it easier to create overlays.
Do We Have a Winner?
The reason bot the formats are still used is because the answer to “which” is connected to “why”. Both JPEG and PNG have their own set of advantages and downsides. In some scenarios, size matters more than the quality but in other cases, quality is more crucial. Of course, finding the balance is the key but both the formats have their inclinations.
JPEG is more suitable when it comes to compression large size images such as real-life photographs. For images with lots of colours and shades, JPEG can do a much better job. The size of a JPEG is likely to be smaller than a PNG.
Since PNG is a lossless compression, there is a limit to how much it can compress an image with too many colours and shades. That is why it is much preferred for images with less colour but more contrast. This includes graphical illustrations, logos, and images with texts on them. That is why you see them everywhere on the web.
Conclusion
Many argue that PNG is more advanced than JPEG and there is hardly any reason to choose the former anymore. That is not true, JPEG can be very useful when you can afford to lose a bit of quality to reduce the size as much as possible. Also, it precedes the PNG format by decades and is compatible with more devices and applications. However, for better contrast and quality PNG is now much preferred by designers and developers.