Saving images for the web/ file compression/ quality
image saved as a .JPG image saved as a .GIF BBC Bitesize
Saving a image in a particular format such as .jpg and .gif can change the quality of the image. Uploading a image in a .JPG would mean that the image upload quicker and using less data. it is the most popular format for a picture. Uploading a image in a .GIF file means that the image is bigger and would take up more data when uploading and take longer.
Lossless and Lossy data
Lossless data compression allows media to be represented without any loss in quality or information, while Lossy data compression may result in a loss of quality and information.
The most common Lossless media types include GIF, PNG, and TIFF, while JPEG is the most common of Lossy graphic media.
You can save a .JPG in JPEG Low, JPEG Medium, or JPEG High. The image below shows the difference. (http://www.tutorial9.net/)
Compression
Compression
is used in computers so that a file can be made smaller so that it takes up
less space on a computer or so it can fit onto a mobile device like a phone or an
mp4 player.
You can download compressing software off the internet;
it works by allowing you to change the format it is in, because some formats
use up more space than others. An mp4 file might take up less space than a M4V
file bought off iTunes because the mp4 file is designed to be played on a small
device like an iPod or a phone as the quality is much lower so that a small
device can play it. Also data compression can be used so that large files can
be made smaller so that they can be sent over the internet by someone like
email.
Compressing a file can change the quality of a
file like audio or video by lowering the sound/video quality, the resolution
and the bit rate. Lossy compression reduces bits by finding the least important
information and removing it.
I
compressed a large video file that had been filmed from an iPad 3 which was a
.mov file and was filmed in HD and managed to compress it using a file
compressor so it could fit on my phone and on to my laptop as the file was
about 1gb and managed to reduce the size significantly by changing the file to
a mp4 file
Popular digital file types
JPEG is a compressed file format that supports 24 bit colour This is the best format for photographs to be shown on the web. This is because the colour informational bits in the computer file are compressed (reduced) and download times are minimized and uses less data when loading.
GIF is an uncompressed file format that supports only 256 distinct colours. Best used with web clip art and logo type images. GIF is not suitable for photographs because of its limited colour support and is a lossless format which means the file is big so that it will take longer to load and uses more data.
TIFF file stands for Tagged Image File Format. U sed a lot in graphic design as they are high quality. The file extension for a TIFF file is either .tiff or .tif. The files can be saved without compression, or they can be compressed to lower file size, similar to JPG files. TIFF files are commonly used in print design and desktop publishing because they can store large, high quality images such as photos. . Not suitable for images on the web as the sizes are large and are a lossless file meaning that they are uncompressed and will be a large file. Also some web browsers dont let you view them
RAW is an image output option available on some digital cameras. It is lossless but it alot smaller than than TIFF files.
No comments:
Post a Comment