Explain how different types of graphic images relate to file formats

• Easy to create from existing files
• Pixel values may be modified individually or as large groups
• Supported by virtually every device
• Does not degrade when saved multiple times like JPEG does
• Very large file size
• do not scale very well
• Lacks all the other features of the other formats

GIF images are typically used for line art with limited colours and images with large flat areas of colour. They are also used for images that may need to be animated.        

• Transparency is supported
• Good for saving crisp, clean line art
• Good for saving images with lots of flat, solid colours
• Animation is supported
• Only supports up to 256 colours
• “Binary” transparency (a pixel is either transparent or not)
• License issues (the way it encodes the image data is patent protected – so, in theory, you should be paying a licensing fee to save GIF images)

PNG format images are best for images with lots of flat colours and those images that require smooth areas of transparency.        

• Supports full transparency
• Supports a full spectrum of colours
• Completely lossless (doesn’t degrade over multiple saves like JPEG does)
• “Progressive rendering”
• “Alpha” Transparency isn’t supported in older browsers without “work-arounds”

SVG is used for Vector images like line art, logos, graphs and images that change over time or may need to be animated.        

• Tiny files – only lists the lines/curves and shapes that make up the image
• Can be scaled up and down without loss of clarity
• Interfaces with JavaScript to create animated or changeable images
• Only supported in modern browsers (although it is possible to work-around this limitation)
• Can’t make overly complex images like photographs

The PSD file extension is given to files that have been created by the Adobe Photoshop computer application.        

• Can preserve layers. PSD files can handle simple vector layers, making them more suitable for importing and exporting data from programs like Adobe Illustrator.
• PSD files’ large size and capability to save significant amounts of file information make them an excellent choice for working files.
• PSD files tend to be extremely large, since these lossless images use no compression. This preserves all image information, but can make the file itself unwieldy and difficult to email or transfer
• Very few other programmes will understand open or import PSD files.

In conclusion, there are many different types of graphic images related to file formats. Each have many benefits over other file types and disadvantages over others. It is important to pick a file type that is specific to the project you are working on.