Colour Space
The range of colours a device can recognise eg. those a printer can print, and those a monitor screen can produce. for print we should use the CMYK colour space Cyan, Magenta, Yellow, Key (Black) these four are the colours most printers use to recreate a photoshop image for the web we should use RGB Red, Green, Blue. computer monitors combine these three to recreate a whole range of other colours; if you look close enough at a monitor screen you can see this. the CMYK colour space recognizes less colours in the colour spectrum than the RGB colour space printing. an RGB document will therefore appear washed out when printed. as the computer screen shows more colours than a printer can print
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Image Compression
What is compression?
Image compression is the process of making an image file smaller by taking out the unnecessary colours. medical images and technical drawings use 'lossless' compression, whereas photographs use 'Lossy' compression.
How does compression work?
It works by removing colours that are not needed in the image.
When is it useful?
When sending image files via the internet.
What are the two types of compression?
Llossy and lossless.
Which file formats use which of these types of compression?
Lossy (lose information) - JPEG, GIF
Lossless (lose nothing) - PNG, PSD, EPS
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Creating a new file on Photoshop cs4
Before you begin creating your photoshop project, set the file to the right size or select a preset. double click on the background layer icon in the bottom left of the screen. layering is a way of placing images on top of each other in separate layers. to colour a layer select a colour, click layers on the top tool bar, click select, then layers, new fill layer, then gradient (after which you would choose your preferred pattern) or fill. select the capitol 'T' icon on the left tool bar then click in the space to begin typing text. You can then drag the text to wherever you want it, and also use the size adjusting points in the corners of the text to change the size.
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Image File Types
PSD - Photoshop Document
PNG - Portable Network GraphicsTIFF - Tagged Image File FormatPDF - Portable Document Format.
JPEG - Joint Photographic Expert Group (the group who created the JPEG file type)
GIF - Graphics Interchange Format
EPS - Electronic Post ScriptBMP - Bitmap
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