Introduction
When it comes to digital images, there is no one-size-fits-all solution when it comes to image file formats. Different image file formats have their own strengths and weaknesses, and each can be used in different circumstances depending on the desired output. In this article we will provide an overview of popular image file formats and discuss when and how to use them for best results. We will look at JPEG, PNG, GIF, TIFF, BMP and RAW images as well as compare them with each other to determine which format is best suited for your needs. Finally we will explore how to optimize images for web use so that they are displayed correctly on any device or platform.
Overview of Image File Formats
Image files are digital pictures stored on a computer as either raster or vector graphics. Raster graphics are pixel-based, meaning they are composed of individual pixels of color, while vector graphics are based on mathematical equations that define the shape and size of the image. Images can be stored in a variety of file formats, each with its own set of advantages and disadvantages. The most popular image file formats include JPEG, PNG, GIF, TIFF, BMP, and RAW images. Below is an overview of these different types of image files and when to use them.
An overview of popular image file formats
You save your digital photos in JPEG format. Still, nowadays, when you download an image from the Internet, it may be in the more modern WebP format.
You may also be familiar with GIF animations, which are a decade old but have regained popularity with stickers and memes. Even if you want to save a screenshot, many file types are available in Paint.
The question is: Why do we need so many file types? How do they differ from each other, and how do the newer formats differ from, the older ones? Which configuration should be used when saving an image?
Below is an introduction to the most basic and standard image file formats, so you can familiarize yourself with them and learn about their advantages.
JPEG
In 1992, the Joint Photographic Experts Group created an industry-standard to store digital photos without significant color loss efficiently.
To achieve this, we store each block of eight by eight pixels as a combination of up to 64 patterns rather than storing individual pixels. As a result, the image appears blurred at close range.
There is a possibility that the 64 patterns with the highest complexity will be ignored, resulting in a significant reduction in file size but an artifact, possibly in the form of large, solid squares.
As another means of saving space, the color components of the image are recorded at one-quarter the resolution of the brightness component. This is because the human eye is less sensitive to changes in hue than to changes in brightness.
With reasonable quality settings, you will hardly notice any difference in nature photography. After all, nature is not made up of perfectly straight lines, and PNG is the best choice if you want to take a screenshot that contains the text.
JPEG is a popular image format that stands for Joint Photographic Experts Group. It is used to store, view and transmit photographic images on the internet and in digital cameras, scanners, etc. This image format utilizes a “lossy” compression technique which makes images smaller in file size while retaining reasonable quality. JPEGs are used for web graphics such as icons, logos and photographs due to their small file sizes and good amounts of detail they can capture. The default level of compression can be adjusted allowing higher or lower levels of quality with different trade-offs between file size and image resolution. The maximum number of colors JPEG supports is 16 million.
PNG
In 1995, the Portable Network Graphics Format (PNGF) was proposed by a group to replace GIF. Still, it is arguably a more direct replacement for the bitmap format, which is not compressed.
PNG offers lossless compression that reduces file size by repeating patterns within the image. It is recommended to use PNG format if you want to edit your image further or save an accurate screenshot. This format supports both full transparency and partial transparency.
Although each APNG file contains one image, the extension is supported by all modern web browsers. It allows you to create GIF-style animated images with a more significant number of colors than GIFs.
PNG images have a much larger file size than GIF or JPEG images since they contain much more data. Nevertheless, when they contain the same information, they are comparable to GIF files and sometimes even smaller, depending on the software used for compression.
The Portable Network Graphics (PNG) format was developed as an open-source alternative to the GIF file format. PNGs are commonly used for web graphics, logos, and other types of images that require a transparent background. The lossless compression technique used by PNGs allows them to maintain image quality while also providing small file sizes and fast loading times.
PNGs support 8-bit or 24-bit images with up to 48 bits of color depth, although they are typically saved in 8-bit mode. They can be used for both photograph images and non-photograph like illustrations since they have the ability to handle complex shapes, text, and transparency effects well. From a design standpoint, it’s often better to use PNG than another file type such as JPEG because it does not lose any data when compressing images - no matter how many times you save it. Additionally, all modern web browsers are capable of displaying this format without needing any additional plugins or software installed on the user’s device.
All in all, the versatility and convenience that comes with using the PNG format makes it one of the most popular image formats available today. Its suitability for a wide range of applications is hard to match; from optimizing photographs for sharing on social media websites to creating high quality vector based illustrations – there is truly no wrong way to use a PNG image file.
WebP
In 2010, Google announced the WebP format to replace GIF, JPEG, and PNG files with lossy and lossless compression algorithms, animations, and transparency. Does it perform all these functions as well as other formats?
Whether WebP has an advantage over PNG in terms of lossless compression and APNG seems more effective, especially for animated images. The WebP format, on the other hand, offers excellent lossless compression that produces files many times smaller than the original, allowing you to discover the differences for yourself.
Browsers also support WebP, with one important exception. In the past, WebP wasn't widely used because it wasn't supported by Safari, which meant a large portion of Internet users didn't have access to this image format.
However, iOS 14 introduced support for WebP. Since iOS versions are quickly adopted, and people tend to replace their smartphones more often than their desktops or laptops, the remaining problem is the lack of support for older macOS versions.
The next generation of WebP is under development, known as WebP 2, which is expected to be more competitive with another next-generation format, AVIF.
AVIF
YouTube and Netflix use the AV1 video codec for their video streaming service on Android devices. AVIF, based on AV1 and stored in the HEIF container, was developed by the Alliance for Open Media. HDR and more expansive color spaces are among the features it supports over WebP.
Mozilla is working on adding support to Firefox, so Chrome will also support the format. In addition to Vimeo, Netflix has also stated it intends to make AVIF the default image format for its supporting browsers.
In addition, to accurately guess color changes based on brightness changes, AVIF has another advantage over WebP. Even when an image is heavily compressed, logos and text, lighter or darker than their background, remain sharp.
JPEG XL
The JPEG committee is standardizing the next generation of image codecs, JPEG XL. By combining Google's PIK codec with Cloudinary's Free Universal Image Format (FUIF), JPEG XL was able to create a product which is more than its parts by leveraging the strengths of Google PIK and FUIF.
JPEG XL is a file format for raster graphics supporting both lossy and lossless compression and is royalty-free. The raster format is designed to outperform and universally replace existing raster formats.
GIF
In 1987, Compuserve introduced the Graphics Interchange Format with the ambitious goal of distributing color images on the Internet. Besides, this format allowed multiple images to be stored in a single file, making it possible to create animations before embedding videos on a website.
The format is space-efficient. This is partly because all the images in a GIF file use a palette of 256 of the 16.7 million colors of the RGB color space (although they can use different 256-color palettes within the same file). With the introduction of transparency in 1989, it became possible to create non-rectangular logos that could be used on various background colors.
Ironically, as videos have become more accessible on the Internet, GIFs have replaced words. Instagram has supported GIFs since 2018, and Facebook has officially supported them since 2015. GIFs have also been available as stickers in Instagram stories since 2018.
The popularity of animated GIFs is due to at least two factors: First, they stand out from the text and still images in comment sections. The second advantage of animations is they require significantly less skill and effort to convey emotion than words or a single image. One need look at the "trending" section of Giphy to see that GIFs are the most commonly used to express emotion online.
If you were to save an image as a GIF, it would be unrealistic because the color gradients would not be recognizable in nature. If you need to capture a series of screenshots and send them via email, GIF may be the best choice, although PNG is much better due to its lower compression.
GIF stands for Graphics Interchange Format and is a popular image format used commonly on the web. It is an 8-bit file format, meaning it can store up to 256 colors in its palette, making it ideal for images with flat areas of solid color and sharp edges. GIFs are compressed using a lossless algorithm, which means that no detail or sharpness is lost during compression. This makes them great for smaller filesizes without sacrificing quality. Despite their limited color range, they are still suitable for logos, icons, diagrams and simple illustrations with few colors. They also have animation capability where multiple frames can be grouped together to create short animated sequences such as animated icons/logos or short video clips.
SVG
Released by the World Wide Web Consortium in 2001, it differs from the other formats we've discussed so far in that it's made of shapes rather than pixels, which means the image remains good regardless of the magnification or size of the paper it's printed on.
Since SVG images are made of text, they can be created and edited with text editors or embedded as code in websites. Special programs such as Adobe Illustrator and Inkscape are used to create them. In addition, SVGs are capable of supporting animation, including interactive animation. All modern web browsers support SVG rendering.
As discussed in this article, vector graphics have the disadvantage of being much heavier and more extensive than raster graphics. Vector graphics are not helpful for photos, but they are best for images with few shapes, such as logos.
HEIC
This format is based on the HEVC format and is often used to store images and videos. Since iPhones use this format and store images in it, it is used more and more.
As the standard for storing photos, JPEG has had a significant impact on the popularity of digital photography. Several years ago, Apple changed the standard format for image storage in its products from the High-Efficiency Image File Container format to the High-Efficiency Image Container format, which is based on the High-Efficiency Video Coding format.
Currently, there is no native support for HEIC in web browsers. A second problem with JPEG occurs after you edit and save the image because the pixels around the edited portions of the image are recompressed once the file is saved. Multiple edits and saves can significantly affect the quality of an image.
BMP
The earlier versions of Windows popularized the BMP format. Since bitmap files are not compressed, they have large file sizes, while more modern formats like PNG can achieve similar results.
BMP, or Bitmap, is a popular raster-based image format that has been around since 1987 and used in Microsoft Windows operating systems. It is an uncompressed file format with support for indexed and true color depth pixels, and it can also store photometric images with high dynamic range (HDR). BMP files are commonly used for storing screenshots and other digital photographs, as well as some basic graphic design elements like logos or icons. The main advantage of using a BMP file is its broad compatibility with different programs and operating systems—most word processing applications will recognize the file type regardless of platform. Additionally, because the files are larger than their compressed counterparts, they often remain sharp even after being resized to fit different device screens.
TIFF or TIF
TIFF image formats have been used for more than two decades and remain popular, especially in publishing, among photographers and GIS applications that use the GeoTIFF extension to embed data in the bitmap. Because this format preserves image quality during processing, it has little or no compression. It is not widely used on the Internet due to its large file size.
Tagged Image File Format (TIFF) is one of the most popular image file formats. It is a raster graphics format commonly used for storing high-quality images and photos with both lossless and lossy compression options. The format supports CMYK, RGB, Lab color models, ICC profiles, alpha channels, and layers as well as non-RGB color spaces. Being an uncompressed format, it can often consume a lot of disk space but produces very high quality images suitable for printing purposes. TIFF files are typically larger than JPEGs or GIFs but offer more flexibility when editing since they can store more information in the form of layers and other metadata. They also offer additional control over image details such as sharpness and contrast that makes them ideal for retouching photographs or creating illustrations from scratch with powerful tools like Photoshop or GIMP.
RAW
RAW images, which have multiple file extensions, are minimally processed and use as much information as possible from the image sensor of a digital camera or other type of image scanner. RAW images are typically used by photographers.
RAW image files are a type of image format popular among professional photographers. These images contain minimally processed data from the camera’s sensor and provide the highest quality digital images available. RAW images are not compressed, meaning they have a much larger file size than other types of image formats like JPEG or PNG, but they also retain an immense level of detail and give you far more control when it comes to post-processing and editing. Because of this increased control, editing RAW images is recommended for professionals who need to make changes while preserving as much quality as possible. However, due to their large file size, they are not suitable for web use unless they have been converted into a smaller file format first.
Comparing Image Formats
When it comes to comparing image file formats, there are some common factors that can help determine the best option for your needs. These include the amount of detail stored in the image (i.e, its resolution), compression types and ratios, color information, transparency support, animation capabilities, vector compatibility, and file size. JPEGs offer high-quality images with excellent compression and a wide range of color types and resolutions; PNGs provide good quality lossless compression with support for transparency effects; GIFs are capable of displaying basic animations; TIFFs provide superior resolution but require large files sizes; BMPs are uncompressed bitmap images with no built-in lossless or lossy compression options; RAW images offer maximum control over editing details but tend to be very large files; and finally SVG (Scalable Vector Graphics) offers a vector format that can scale without losing quality. Each type has its own advantages depending on what you need from an image file format.
Choosing the Best Image Format for Your Needs
When it comes to choosing the best image format for your needs, there are a number of factors that need to be taken into consideration. It is important to understand the differences between each file type and how they can affect the quality and size of an image. JPEGs are great when you need a small file size but with good quality. PNG files offer better compression than JPEGs, while still providing good quality, but might not be suitable if you require extremely high-quality images or transparency. GIFs are ideal for animations or images with few colors, while TIFFs and BMPs usually offer higher resolution than other formats. RAW image formats offer more flexibility in terms of post-processing but come at the cost of large file sizes.
It is also important to consider how you will be using the image; if you plan on displaying it on your website, then different considerations must be taken into account compared to printing out the image. Additionally, some hosting platforms may require specific sizes or resolutions for certain images so this should also be taken into account when choosing an appropriate format.
In summary, selecting the right image format depends on a number of factors such as size requirements, color support (for GIF's), resolution (for TIFF's & BMP's) and editing capabilities (for RAW). Careful consideration should be given before making your decision in order to ensure that you have chosen an appropriate format that meets all your needs without compromising either quality or size too much.
Optimizing Images for Web Use
Optimizing images for web use is essential in order to ensure fast page loading times, better SEO rankings and a better overall user experience. In this chapter, we’ll cover some best practices for optimizing your images before you upload them to the web. First and foremost, you should always keep the file size of your images as small as possible without sacrificing quality. Image compression tools like JPEGmini or TinyPNG are great for reducing image file sizes without noticeably affecting the quality of the photo. Additionally, it’s important to optimize your images for specific devices; different device screens have different resolution requirements, so make sure that you’re providing an image that looks good on all types of screens. Finally, be mindful of how many images you include on each page; too many images can lead to slow loading times and poor user experience. With these tips in mind, you can rest assured that your website visitors will enjoy a pleasant browsing experience when viewing your pages with optimized images.
Conclusion
In conclusion, there are many image file formats available to choose from and knowing when to use each one is important in order to create the highest quality images. JPEGs are best for photographs, PNGs are good for screenshots, GIFs are ideal for simple animation or small graphics with limited colors, TIFFs offer a high degree of control over color settings and compression levels, BMPs provide lossless compression and maximum compatibility with Windows systems, RAW images contain all of the original data from the camera sensor and can be manipulated extensively in post-production, and finally comparison tools help you pick the most suitable format for your needs. Ultimately it’s up to you which format you decide upon for any given project but with these guidelines you should have a better idea of where to start.