Guide to Understanding the PNG Image Formatting

Recognizing Digital Image Formats

You can utilize a variety of digital picture formats, but only a few of them are optimized for web use. The TIFF image format, for example, is not intended for website use; it is intended for printing. JPEG, GIF, PNG, and SVG are examples of web image formats.

Why some picture formats are appropriate for the website, and others are not? Because photographs on the website must be optimized and thoroughly compressed in order to avoid becoming too large. Some digital picture formats, particularly those developed for print (such as TIFF), have needlessly good res, metadata, and color intensity — all of which become meaningless when viewed on computer monitors — and are therefore too large in file size for web use.

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Methods of Compression

Image compression methods are classified into two types: lossy and lossless. Lossy compression occurs only when the compression algorithm utilized results in some data loss. This implies that if you attempt to decompress it, you will not obtain the precise or same image as the original.

In most cases, data loss is conducted in such a manner that you don’t compromise on too much clarity, at least enough that people do not notice. Lossless compression, on the other hand, is the inverse of lossy compression. Lossless compression employs compression methods that, when decompressed, produce a picture that is identical to the original.

When you zip up any document by using the ZIP format, you are performing lossless compression. But when you want to unzip your document, it will seem just like the original. This is because the PNG format employs a lossless compression method.

JPEG, on the other hand, employs a lossy compression method. This simply implies that if you save your original photographs as JPEG, you may see some compromise in the quality.

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Some PNG Technical Information

PNG is a bitmapped image file format, which simply implies it is a raster image format, in addition to utilizing lossless compression. Raster pictures, unlike vector image forms such as SVG, cannot be resized without losing quality if you skip Design 101. However, for complex pictures such as photographs, raster images outperform vector ones.

Because PNG was developed for swiftly uploading images over the web and showing images on computer screens, it only supports the RGB color model. Furthermore, when storing photos in PNG format, the CMYK color type, which is normally used for printing, is not available. In brief, the PNG format is not suitable for printed graphics.

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PNG Sizes

PNG comes in two sizes: PNG-8 and PNG-24. The numbers are abbreviations for “8-bit PNG” or “24-bit PNG.” To avoid getting too technical — because as a website designer, you may not care — 8-bit PNGs signify the image has 8 bits per pixel, and 24-bit PNGs have 24 bits per pixel. In layman’s terms, the distinction is as follows: Let’s just say that PNG-24 can accommodate a lot more color and is better for sophisticated images with a lot of colors, like photographs, but PNG-8 is better for items with simple shades, like logos and user interface components such as icons and buttons. Another distinction is that PNG-24 allows alpha transparency natively, which is useful for transparent backgrounds.

This distinction is not entirely accurate because Adobe products’ Save for Web command supports PNG-8 with alpha transparencies.

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When Should You Use PNGs?

The PNG image format is ideal for preserving transparency and vast amounts of color while achieving full or partial transparency. Photos stored in the PNG format will not always be small because it is a lossless format, but because PNG saves a lot of extra data, you can simply optimize images for online consumption to reduce file sizes.

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PNG, GIF, and JPEG

Let’s weigh the benefits and drawbacks of utilizing PNG against the two other prominent website image formats.

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PNG and GIF

Always choose PNG over GIF unless you’re creating an animated GIF or want to use pictures with transparent backgrounds in previous versions of Internet Explorer. PNG has some huge benefits over the GIF format that Web Design would appreciate, including:

1. It provides greater compression than the GIF, with a difference of up to 25% in file size.
2. No permit is necessary.
3. The W3C maintains an open file format.
4. 100% lossless compression
5. True alpha transparency on website browsers that accept it (most of them, excluding outdated versions of Internet Explorer).

There are many other benefits, but these are the ones that are important to web designers. For example, you would not use PNG-24 because it has simple colors and weighs more than GIF.

However, the PNG vs GIF argument remains valid: if you save an image (such as a picture of your grandparents), PNG-24 will produce a better outcome than GIF.

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JPEG vs PNG

When it comes to photographic images, JPEGs will have smaller file sizes than PNGs. This is due to the fact that it employs a lossy compression method intended exclusively for photographic, rich-color photos. So, if you’re posting a photographic image on a website page (such as an image of your dog), always use JPEG over PNG.

Choosing PNG over JPEG, in this case, will result in larger data size (6-10 times more than JPEG). You can select PNG-24 rather than PNG-8 since it is the right format for photographic photos.

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Conclusion

For web designers, minimizing picture sizes is an important approach to boosting the overall performance of a web page. In a web design, optimized, smaller graphics mean:

1. Accelerated web pages that download faster
2. Reduced bandwidth consumption
3. Less data is required to convey to site users, resulting in less data activity

Furthermore, you should not be scared to manually optimize each image in order to achieve better outcomes and reduced file sizes. You should always apply an image optimizer to get rid of every extra byte. Experimenting and gaining experience will help you choose the best format.

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