Unit 30 D2

There are different types of file format that are used when saving an image. The type of file format depends on the specific image, and some images require different file formats because of the size of them. Bitmap is a file format that is used for larger images rather than smaller ones,  this is because bitmap stores every small pixel that is in the image which makes the image have good clarity, however the file size is bigger than a normal file.  Another file format is a GIF. GIF is a type of Bitmap file however is mainly an animation.  The file size of the GIF’s is good, as they stay at a reasonable size, this is because of the limit of colours that is allowed to be used. JPEG is another file format that is commonly used as it is used for pictures. When an image is saved as a JPEG the image can become pixelated when stretched which lowers the quality of the image.

Compression techniques are when an image is compressed to have a lower file size. There is two different compression techniques, these include lossy compression and lossless compression. Lossy compression is when the compression of an image makes it pixelate in order to make the file smaller. This is because the file can be used more efficiently when it is at a lower size. Lossless is when you compress the file and expect it to be the same as before. This is when the output is needed to be a better quality, this is used when a file is an important document such as a legal document.

Image resolution is the number of pixels that a device can handle. Different devices can handle a different amount of pixels. The pixels are captured by height and length, and then multiplied together, this shows how many pixels a device can handle. The more pixels a device can handle the more clearly the images will be, However depending on the device depends on how you can save the images. If the device can handle a lot of pixels but has hardly any memory, then you will need a memory stick, or to make some more room. As the more the pixels the larger the file size.

Colour depth is the number of bits used to indicate the colour of a single pixel.  Depending on the bits depends on how defined the colour is going to be. If there is more bits then more shades of colours can be produced, this will make the quality of an image higher, as the colour will be more defined then if there was less bits. The more the colour is defined and enhanced the larger the file will become due to the more pixels that it has to use for the colour depth.