Image File Formates
The standard meaning of image file formate is organizing and storing digital images. An image file format may store data whether in an uncompressed format or a compressed format or a vector format. Image files are composed of digital data in one of these formats so that the data can be rasterized for use on a computer display or printer.
There are hundreds of image file types. The PNG, JPEG, and GIF and many more formats are used to display images on the Internet. Some of these graphic formats are listed and briefly described below, separated into the two main families of graphics:
- Raster formats
- Vector Formats
Raster vs. Vector
Raster Image Files
Raster images are constructed by a series of pixels, or individual blocks, to form an image. JPEG, GIF, and PNG are all raster image extensions. Every photo you find online or in print is a raster image.
In order to retain pixel quality, you cannot resize raster images without compromising their resolution. As a result, it is important to remember to save raster files at the exact dimensions needed for the application.
Vector Image Files
Vector images are far more flexible. They are constructed using proportional formulas rather than pixels. EPS, AI and PDF are perfect for creating graphics that require frequent resizing. The real beauty of vectors lies in their ability to be sized as small as a postage stamp, or large enough to fit on a large image!
In this tutorial, I will only talk about the rater image formate because most of the image formate used are raster formats. Here are the best 7 image formate described below_
1. PEG (or JPG) – Joint Photographic Experts Group
2. PNG – Portable Network Graphics
3. PSD – Photoshop Document
4. TIFF – Tagged Image File
5. GIF – Graphics Interchange Format
6. PDF – Portable Document Format
7. RAW – Raw Image Formats
- PEG (or JPG) – Joint Photographic Experts Group
JPEGs might be the most common file type you run across on the web. JPEGs are known for their “lossy” compression, meaning that the quality of the image decreases as the file size decreases. JPEG-compressed images are usually stored in the JFIF (JPEG File Interchange Format) file format. The JPEG/JFIF filename extension is JPG or JPEG. Nearly every digital camera can save images in the JPEG/JFIF format, which supports eight-bit grayscale images and 24-bit color images
JPEG stands for Joint Photographic Experts Group, which created this standard for this type of image formatting. JPEG files are images that have been compressed to store a lot of information in a small-size file. JPEG files are usually used for photographs on the web because they create a small file that is easily loaded on a web page and also looks good. JPEG files are bad for line drawings or logos or graphics, as the compression makes them look “bitmapped”
- PNG – Portable Network Graphics
PNG stands for “Portable Graphics Format”. It is the most frequently used uncompressed raster image format on the internet. This lossless data compression format was created to replace the Graphics Interchange Format (GIF). PNG file format is an open format with no copyright limitations. Like GIF images, PNG also has the ability to display transparent backgrounds. PNGs are amazing for interactive documents such as web pages but are not suitable for print. While PNGs are “lossless,” meaning you can edit them and not lose quality, they are still low resolution.
The reason PNGs are used in most web projects is that you can save your image with more colors on a transparent background. This makes for a much sharper, web-quality image. The PNG (Portable Network Graphics) file format was created as a free.
PNG provides a patent-free replacement for GIF (though GIF is itself now patent-free), and can also replace many common uses of TIFF. Indexed-color, grayscale, and true color images are supported, plus an optional alpha channel. It’s used almost exclusively for web images, never for print images. For photographs, PNG is not as good as JPEG, because it creates a larger file. But for images with some text or line art, it’s better. When you take a screenshot on your Mac, the resulting image is a PNG–probably because most screenshots are a mix of images and text.
- PSD – Photoshop Document
PSD file is a layered image file used in Adobe PhotoShop. PSD, which stands for Photoshop Document. When an image is complete, Photoshop allows the user to flatten the layers and convert the flat image into a.JPG, .GIF, .TIFF or other file format so it can be shared. This is the default format that Photoshop uses for saving data. Once a PSD image has been flattened by conversion, however, it cannot be converted back to PSD.
PSDs are files that are created and saved in Adobe Photoshop, the most popular graphics editing software ever. This type of file contains “layers” that make modifying the image much easier to handle. That is why this formate is very much popular among the editor. As the layer is saved in the PSD file so the next editor can easily move on his next editing process.
The largest disadvantage of PSDs is that Photoshop works with raster images as opposed to vector images. Comparing to JPEG and PNG file PSD file size is quite bigger. The more layer you use in the photoshop the file size will increase. So that may make you in difficulties for transferring, storing or sharing a large image.
- TIFF – Tagged Image File
TIFF stands for Tagged Image File Format. TIFF images create very large file sizes. TIFF images are uncompressed and thus contain a lot of detailed image data. TIFF is best for any bitmap images that you intend to edit. TIFF files don’t compress to make for smaller files, because they are meant to preserve quality. This file type is known for using “lossless compression,” meaning the original image data is maintained regardless of how often you might copy, re-save, or compress the original file. TIFF files are large and of very high quality.
Four types of baseline TIFF images are available: bi-level (black and white), grayscale, palette, and RGB. RGB images may store up to 16.7 million colors. Palette and gray-scale images are limited to 256 colors or shades. A common extension of TIFF also allows for CMYK images.
The TIFF format is a flexible format that normally saves eight bits or sixteen bits per color (red, green, blue) for 24-bit and 48-bit totals. TIFF is the most common file type used in photo software such as Photoshop because a TIFF contains a lot of image data. TIFF image format is not widely supported by web browsers. TIFF remains widely accepted as a photograph file standard in the printing business.
- GIF – Graphics Interchange Format
The Graphics Interchange Format is a bitmap image format that was developed by a team at the online services provider CompuServe led by an American computer scientist. It has since come into widespread usage on the World Wide Web due to its wide support and portability between many applications and operating systems.
The format supports up to 8 bits per pixel for each image, allowing a single image to reference its own palette of up to 256 different colors chosen from the 24-bit RGB color space. It also supports animations.
GIF images are compressed using the Lempel–Ziv–Welch (LZW) lossless data compression technique to reduce the file size without degrading the visual quality. This compression technique was patented in 1985.
This is a common file type for web projects where an image needs to load very quickly, as opposed to one that needs to retain a higher level of quality. GIFs also have an extremely limited color range suitable for the web but not for printing. This format is never used for photography, because of the limited number of colors. GIFs can also be used for animations.
- PDF – Portable Document Format
The Portable Document Format (PDF) is a file format developed by Adobe in the 1990s to present documents, including text formatting and images. Today, PDF files may contain a variety of content besides flat text and graphics including logical structuring elements, interactive elements such as annotations and form-fields, layers, rich media (including video content) and three-dimensional objects using U3D or PRC, and various other data formats.
If a designer saves your vector logo in PDF format, you can view it without any design editing software (as long as you have downloaded the free Acrobat Reader software), and they have the ability to use this file to make further manipulations. This is by far the best universal tool for sharing graphics. PDFs were invented by Adobe with the goal of capturing and reviewing rich information from any application, on any computer, with anyone, anywhere.
- RAW – Raw Image Formats
A RAW image is the least-processed image type on this list — it’s often the first format a picture inherits when it’s created. When you snap a photo with your camera, it’s saved immediately in a raw file format. Only when you upload your media to a new device and edit it using image software is it saved using one of the image extensions explained above.
RAW images are valuable because they capture every element of a photo without processing and losing small visual details.
Raw image files contain data from a digital camera (usually). The files are called raw because they haven’t been processed and therefore can’t be edited or printed yet. There are a lot of different raw formats available! Raw files usually contain a vast amount of data that is uncompressed. Because of this, the size of a raw file is extremely large. Usually, they are converted to TIFF before editing and color-correcting.