File Type and Format

File Types and Formats

Image Properties

The term pixel is short for "Picture Element." Pixels are small little dots they are what make up the images on computer displays, whether they are flat-screen (LCD) or tube (CRT) monitors. The screen is made up of thousands maybe even millions of pixels, by having more on the screen it makes it look smoother, also you cannot see an individual pixel because they are so small.  

Image resolution is the detail an image holds. As the resolution goes up, the image becomes clearer and it becomes more defined, and more detailed as well. Resolution is sometimes identified by the width and height of the image as well as the total number of pixels in the image. For example, an image that is 2048 pixels wide and 1536 pixels high (2048X1536) contains 3,145,728 pixel.

There is also the colour intensity which is the amount of colour used in the picture, the colours that tend to be used are these, Red, Green, Black and Blue.

Compression

Compression is the process of reducing the size of a file, this is sometimes used when sending an email. There is a down side by doing this because the less there is in the file the more blurry the image is.Compression is good for photos that need a smallish file size.

Lossy compression is a data encoding method that compresses data by losing some of it. Lossy compression attempts to eliminate unnecessary information from the file.

Lossless compression is different to lossy because it does not lose any data in the compression process. Lossless compression is also handy for storing files as they take up less room.

Types of Digital Graphics

Raster is a quite a large file size because the file has to record information on what is held in every single pixel, raster is also known as bit-map. Raster (bit-maps) are very good for photographs as they reproduce colour accucurately. Also raster image is a collection of dots called pixels and each pixel is a tiny colored square.

Bmp

Bmp is also known as bitmap. It is a file format found mostly in computers that is used in the storage of digital photo and it was introduced on the Windows platform, but is now recognized by many programs on both Macs and PCs. The Bmp format stores colour data for each pixel in the image without any compression. This method of storing image information allows for crisp, high-quality graphics, but also produces large file sizes.

 

Gif

Gif is good for drawing/line art for example a world map, but is not so good for photos with 256 colours in the photo and Gif always uses lossless LZW compression. This is best used for making animated pictures.

 

Tiff

 

Tiff stands for tagged image file format. This is a file format for storing images, it is popular among graphic artists and the publishing industry. TIF is lossless which is considered the highest quality format for commercial work. TIFF supports most colour spaces, RGB, CMYK, YCbCr, etc. TIFF is a flexible format with many options. TIFF is uses an amazing quality image photographys are an example of a TIFF.

Jpg

In computing jpeg is a commonly used method of lossy compression for digital photography or image. This is the right format for those photo images which must be very small files, for example, for web sites or for email .JPEG images have a low resolution (72 dpi), therefore they are unsuitable for high quality print output.

Vector images are images made up of many individual, scalable objects. These objects are defined by mathematical equations rather than pixels, so they give the highest quality images. File sizes are smaller because only co-ordinates and number are stored in the file.

Psd

Of all the file formats that Photoshop supports, the PSD format is probably the most important. PSD stands for "Photoshop Document". PSD is one of the few file types that fully support all of the powerful features that Photoshop gives us, like layers, layer masks, adjustment layers, channels, paths, etc.

Fla

The fla file format is the document for Flash projects. Fla files can only be opened in Flash. The FLA file is the editable project file saved by the Flash development program and the SWF file is a compressed format that is viewable in most Web browsers with the Flash plugin.

Ai

 

Vector image file created by Adobe Illustrator, composed of paths or lines connected by points instead of bitmap data, include objects, colour, and text often referred to as an Illustrator drawing.