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Monday, 14 March 2011

Getting Started With a PhotoShop - Masks and Channels

Masks and Channels
What are Channels?
Channels are "containers" for storing information. There are two kinds - color and selection. You can have up to 24 of them in an image.
What are masks?
Masks are like stencils that protect parts of an image. There are also two kinds - temporary (quick masks) and permanent (alpha channels)

Color Channels
An RGB image has four color channels - red, green, blue and a composite RGB channel. You can perform color corrections on individual channels for precise adjustments.

Alpha Channels
These contain selection information. When you make a selection using one of the selection tools, the area within the selection is editable and the area outside is protected - or masked. You can store selections as alpha channel where they will be saved for use again in the future. When you display an alpha channel, the masked area is black and the selected area is white. The masks can be edited with the painting tools while in the alpha channel

What is a mask?
A mask is like a stencil placed over the image that allows you to edit only a part of the image while the rest - the area covered by the stencil - is protected. Both the protected area and the selection can be edited. Quick Masks are temporary masks which can be invoked from the toolbar and created with selection and painting tools . They can be converted to selections or saved as alpha channels.

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Add and Subtract blending modes (1) Adobe Bridge (1) Applying transformations (1) Artistic (1) Blur (1) Brush Stroke (1) Choosing preset page views (1) Creating New Images (1) Creating temporary masks in Quick Mask mode (1) Digimarkmarc filters (1) Duplicating layers (1) Editing Menus (1) Filters - Choosing effect (1) Filters - Defining undistorted areas (1) Freezing and thawing areas (1) Guidelines for using the History Palette (1) Improving performance (1) Loading a selection into an image (1) Loading images and textures (1) Making Color adjustment (1) Making Sticky Note (1) Noise (3) Pagemaker Tutorial - Basic (1) Pixelate (1) Reconstructing distortions (1) Render (1) Replace Color Command (1) Save Changes in the Current File (1) Saving Image Files (1) Saving a mask selection (1) Seeing the color values of pixels (1) Sharpen (1) Sketch (1) Stylize (1) Texture (1) Tips for creating special effects (1) To apply multiple types of transformations (1) To change the Quick Mask options (1) To load a saved selection using shortcuts (1) To repeat a transformation (1) To use the eyedropper tool and Color palette (1) Transforming and manipulating objects (1) Using History Palette (1) Using texture and glass surface controls (1) Using the Calculations command (1) Using the Liquify command (1) Using the Liquify dialog box (1) Viewing Pages (1) Working with Palettes (1) blending effects (1) change the color of frozen areas (1) delete (1) delete a wire frame (1) distort (2) flip or rotate (1) manipulate the object in three dimension (1) masks (1) or apply perspective (1) or hide a color sample (1) reconstruct areas to match distortions (1) rotate (2) scale (1) show or hide frozen areas (1) the eyedropper or color sampler tool (1) use the Info palette (1) using the Apply Image command (1)