The elusive alpha channel remains one of the most misunderstood yet powerful tools in Photoshop. Alpha channels are collections of luminance data that control the transparency of an image, and they inform just about every aspect of Photoshop. Selections, layer boundaries, masks, the Quick Mask mode, layer masks, knockouts, and masking with the Channels palette all rely on alpha channels. In Photoshop CS2 Channels and Masks, award-winning author and Photoshop expert Deke McClelland teaches channels and masks comprehensively. From channel masks to blue screens, blend modes to displacement maps, Color Range to Calculations, this training leaves no pixel unturned. Deke also covers how to select and composite highlights, shadows, people, fabric, feathers, glass, flames, lighting, and wispy hair. Exercise files accompany the tutorials.Topics Include:
- Exploring how channels work in different color modes
- Creating, saving, and loading alpha channels
- Working with the Color Range command and Quick Mask mode
- Building an organic, highly accurate mask from a color channel
- Selecting an image of a person, including hair, and seamlessly merging it onto a new background
- Editing masks by dodging highlights, burning shadows, and Overlay painting
- Using blend modes and luminance blending
- Combining masking with layers as transparency masks, layer masks, clipping masks, and knockouts
- Correcting images using a host of specialty masks, including luminance masks, density masks, color masks, exposure masks, depth masks, and edge masks
- Using the Calculations command to build a base alpha channel from the best of two color channels
- Masking an image photographed against a blue screen or a cloudless sky
- Selecting translucent elements, such as natural shadows and flames
- Masking detailed images against busy backgrounds
- Using a displacement map to wrap one image around the contours of another
