In the world of the image digital, there are many formats, but there are two prevailing. While there is not one that is necessarily better than another, we compared the JPEG format vs. PNG to know when to use them, their main advantages and weaknesses. At first sight, an image in both formats seem identical, but if you look with detention, there is a big difference. The differences respond to that are designed according to the needs of quality, file size, among others. Here’s what you need to know about both formats to get the most out of it.
Acronym for Joint Photographic Experts Group, as they call the team that developed it, the JPEG format is a compressed standard in digital photography and on-line use, thanks to the balance between file size and image quality.
The exact relationship varies depending on the program and settings used, but a JPEG image is typical has a compression ratio of 10:1. That is to say, if it weighs 10 MB and export them as JPEG, the result should be an image of approximately 1 MB.
To do this, JPEG uses a compression algorithm of transformed discrete cosine (DCT, for its acronym in English). Although the underlying mathematics is complicated, it determines which pixels simultaneous are similar and combines them into mosaics or groups that have the same value.
This method is extremely efficient but has the cost of disposing of information that you will not be able to recover. Then, as with a photocopy of a photocopy, every time you open and save a JPEG file, it will look a little worse than before.
For this reason, JPEG is not suggested as a format of image file, because if you ever need to open it and make modifications, you will lose quality. The photo editors are not destructive, such as Adobe Lightroom, help to avoid this problem, always do not delete the original files, as they save the edits as metadata, rather than writing over the original image.
The JPEG format should also be avoided with images with a lot of text or illustrations with sharp, crisp lines, as they tend to appear blurry due to the smoothing. As you can see in the image below, a screenshot of our home page, the text and the white background show a lot of noise in the JPEG (on the right) in comparison with the PNG (left).
That said, there are times when you need to convert formats such as PDF files to JPEG. In such cases, it is best to make sure you export it at the higher quality setting to ensure that all text is clear.
JPEG supports color spaces RGB and CMYK to 24-bit, but their offerings in CMYK leave a lot to be desired. Although modern printers manage very well the RGB files, it is recommended to continue to use high-quality formats for printing. A gray scale of 8 bits is also an option, but the compression ratios are much less impressive than in colour images.
Over the years, many variations of JPEG, have come and gone. For example, JPG-LS was designed to solve the problem of compression with loss of data, but never took hold. JPG2000 also attempted to address this issue, but failed to gain strength. BPG, a format based on the video standard H. 265, was determined to take care of JPEG, but never really understood it.
The creators of the JPEG recently shared a new format, not to replace JPEG, but to coexist as an option for faster transmission. This is the JPEG XS, where the compression is only six times and not 10, but the algorithms more simple mean that the file is faster for tasks such as the transmission.
A potential replacement could be the HEIF, which is also based on the standard H. 265. One of its strengths is the support of Apple. It still has a long way to go, but it can only be a matter of time before it is as extended as the JPEG.
|Small file size||Compression with loss|
|EXIF support built-in||Not recommended for prints CMYK|
|Widely supported||Does not support transparencies|
The PNG is an acronym for Portable Network Graphics and is a file format without loss, designed as an alternative to open up the graphics interchange format (GIF).
PNG uses the LZW compression, the same formats, GIF and TIFF. Although it is more reduced, LZW takes the bit strings contained in the image data, and then match these longer sequences with short codes that are in a dictionary, or code book that is stored within the image file. The result is a smaller file that maintains a high quality.
If we compare the differences of JPEG vs. PNG find a piece of data in the compression. The latter does not have loss of data. Also handles well detailed images of high contrast, so that it is often the default file format for screen captures, as it can provide a nearly perfect representation pixel by pixel of the screen.
One of its prominent features is its compatibility with the transparency. Both color and grayscale, the pixels in the PNG files can be transparent. This allows you to create images that overlap perfectly with the content of an image or web site.
As seen in the GIF, many editing programs, like Adobe Photoshop Mix, use a background to boxes to indicate the transparency of a graphic. This makes PNG ideal for logos, especially those with text, used on a website. If you create a transparent background in Photoshop and save it as a JPG, the background turns white because the format does not support transparency.
When it comes to photography, PNG may seem like a solid alternative to the RAW formats proprietary to the storage of images without a loss, but the truth is that there are many better alternatives, such as the Digital Negative of Adobe (DNG), that you can even film it on your smart phone, and TIFF. PNG also does not support natively the EXIF data, which include information such as the shutter speed, aperture and ISO of the camera with which it was captured.
PNG was made for web and has proven its worth. JPEG may be the format most of the images, but PNG is basically the only option when you need to clearly represent a logo or text over other elements on a web site.
PNG has also had some variations over the years. APNG is a format that is still compatible designed to replicate the functionality animated GIF. It is not so frequent, but is compatible with many modern browsers.
Another interesting fact is that in the early stages of the development of PNG, it was suggested that it be called PING, an acronym for “PNG Is Not GIF”, a mockery to the creators of the GIF format.
|Lossless compression||Larger file size than JPEG|
|Allows transparency||Without EXIF support native|
|Good for texts and screenshots|
Which is better
In the analysis of JPEG vs. PNG we can conclude that none is better than the other and more well-depends on your needs.
If you want to share a picture from your camera in Instagram, Twitter, etc, it is best to JPEG. It is smaller in size, it is optimized for photography and is compatible with almost all platforms and services.
If you store your image, PNG is the best suited. The file size may be larger, but no need to worry about losing any quality each time it is modified, because each pixel maintains its sharpness. Most of the web graphics, such as logos, are also stored better as a PNG, as they can make use of transparent areas.
*Updated as of 9 September 2019 for Daniel Matus.
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