Discuss the impact that file format, compression techniques, image resolution and colour depth have on file size and image quality. The file format is basically the way in which the layout of the image is known as, in order for it to be stored on the computer. Therefore this shows us that due to there being different types of file formats they can be abbreviated, so that they are easily recognised and accessed by the file.

BMP/ DIB also known as the Bitmap file or the Device Independant Bitmap Graphic. This specific file format is used by the Microsoft Windows programs and the Windows Operating systems. Also due to the Bitmap images having a large file size this means that the Bitmap images are made up of a number of pixels, therefore the pixels are formed with picture elements so they are defined as being tiny dots of colours that the user sees on their computer screen. In addition the user is able to change the size of the Bitmap images even though they are relying on the resolution. This means that the the right amount of pixels make up a good quality image. The reason why it is important for the size of the image to stay the same is, because the feature of the image is not lost. For example if the Bitmap image is decreased then the pixels are decreased whereas if the size has increased then more pixels will need to be created using specific software.

GIF also known as the Graphic Interchange Format is mainly used on the web, such as for applications and websites. As well as this format is made up of 256 colours and can display different types of information at the same time. The types of people that would use this format are website designers.

JPEG/ JPG also known as the Joint Photographic Experts Group is used for photos and the continous tone images. This specific format is mainly for web applications and it is quite similar to the GIF file, however the only difference is that the JPEG files store all of its colour data and doesn’t need transparency whereas the GIF files don’t store the colour information. In addition the reason as to why I would not use this file format for my images that I have got from google is, because when I try to print the image or change it’s size for example increase it e.g. stretch it, then the image can become degraded or pixelated. This means that the image quality is lost as it does not look as efficient and it is not clear to see.

TIFF also known as the Tag Information File Format and it is specifically used for the traditional print graphics. Also there are a wide range of programs that support the subset of the options that are available.

PSD also known as the Photoshop Document and there are different features on the Adobe Photoshop program for example image layering.

Compression techniques

There are two different types of compression techniques and these are Lossless compression and Lossy compression. Therefore the compression techniques are used to reduce the disk size of the file. So if the file size is reduced then there is more storage space. However it could also be that the file needs to be moved to a

different location. For example a small file size arrives more quickly than a file with more capacity and information.

Lossless compression is when the images can be rebuilt from the compressed image. Whereas lossy compression is the opposite so this means that the original image cannot be rebuilt from the compressed image.

Image resolution is when the amount of detail the image includes. Therefore it could be for digital images, such as vector or bitmap images, film images and other types of images etc. However if an image has a higher resolution then there is more detail within it and it can be measured in many different ways. This means that the resolution of images just shows how close the lines are to each other and be visibly resolved. In addition the resolution units can be viewed as the physical sizes, such as the lines per image the inch or the overall size of a picture for example lines per picture height.

The reason why colour depth is important is, because it controls the file size and the overall quality of the image.

To conclude looking at the different factors of the images, such as file formats, compression techniques, image resolution and colour depth they each have their own role in maintaining a good quality image and different methods to do so.