One of the key aspects of mastering Digital retouching in PhotoShop is to learn how to select complex shapes. Once you master that. you can do virtually anything, do photo montage, localized color correction, burning, dodging, blurring anything. PhotoShop offers various selection tools, so there are various methods of selecting shapes.Magic Wand
Tolerance: (0-255) The tolerance value selects how much variation range from the selected color will get selected. For a value of 0, the Magic wand will select regions with exactly the same color. Default value for Tolerance is 32, meaning that 32 similar lighter tones and 32 similar darker tones will be selected.
Anti-alised: When checked, it makes the selection edges smooth.
Contiguous: When checked, the Magic
Wand will select only adjacent areas using the same colors, otherwise,
all pixels using the same colors will be selected.
Use All Layers: To limit the selection to the active layer, keep this box unchecked. If you check it, then Magic Wand will select colors using data from all the visible layers.
When working with an image, you may need to adjust these values to gain the best accuracy for your selection.
There are three lasso tools. They come handy in different situations.
Lasso ToolIt is useful when you want to select some area by freehand drawing. This tools is useful when you need to select an area not too accurately as it is difficult to trace a border very accurately by simple freehand drawing.
Polygonal Lasso ToolIf you prefer to draw small segments of connected lines instead a freehand drawing then it is the tool for you. In fact, most of the complex shapes can be traced accurately by using this tool. The trick is to zoom in the area you want to trace and carefully keep of tracing by drawing small segments at a time.
Magnetic Lasso ToolThis Lasso tool has an automatic edge detection, which causes it to snap at the edge of two different colors, so that you need not have to trace the border very accurately. All you need to do is to click to hook on the starting point and then move the Magnetic lasso tool at close proximity of the edge or border you want to trace and it does the rest. It it tries to wander from the edge, you can guide it by clicking an anchor point. This tool is effective if thew picture has very well defined edges. For pictures with fuzzy edges, you have to employ other selection methods.
This tool has a number of settings, similar to Magic Wand
Feather: Blurs edges by building a transition boundary between the selection and its surrounding pixels. This blurring can cause some loss of detail at the edge of the selection. Higher the number you select, wider will be the feathering effect. The default value is 0 pixel, which will cause no feathering. Anti-alised: If this box is checked, then PhotoShop will smooth the jagged edges of a selection by appropriately changing the color of the pixels at the selection border. Since only the color of the edge pixel change, no detail will be lost in the picture. Most of the time you may like to turn it on. Width: To specify a detection width, enter a pixel value for Width. The magnetic lasso detects edges only within the specified distance from the pointer. To specify the lasso's sensitivity to edges in the image, enter a value between 1% and 100% for Edge Contrast. A higher value detects only edges that contrast sharply with their surroundings; a lower value detects lower-contrast edges. On an image with well-defined edges, try a higher width and higher edge contrast, and trace the border roughly. On an image with softer edges, try a lower width and lower edge contrast, and trace the border more precisely.
Frequency: To specify the rate at which the lasso sets fastening points, enter a value between 0 and 100 for Frequency. A higher value anchors the selection border in place more quickly.
Pen Pressure: This option comes handy if you use a graphic tablet. When the option is selected, an increase in stylus pressure will decrease the edge width.
There are three types of Pen tools
Freeform and Magnetic Pen tools are used just like Lasso and Magnetic Lasso way. The simple Pen tool is used just like Polygonal Lasso tool.The difference between a Lasso and a Pen Tool is: Pen tool puts path instead of selection marquee. We can however convert this path into a selection marquee
Paths into Selections
To turn a path into a selection, choose the Make Selection command from the Paths palette or click on the dotted circle load path as selection Button in the Paths window.
PhotoShop Quick Mask helps to do the final cut selection from the rough-cut made by Marquee, Lasso or Pen tools. Once you have the rough-cut selection ready, press the Quick Mask button, which is located at the bottom of the Tool bar as shown in the figure.
This will turn the unselected portion of the photograph tinted into red. Now you can zoom in the picture and use various painting tools like Brush, Spray Can, Pencil to apply or remove the mask to fine-tune the selection.
Use black ink to paint in more mask and white ink to remove it. I have used 5 pixel wide Brush to cover up the bluish highlight on the hair border as shown below
After creating the proper mask, click the standard mode button at the bottom of the toolbar. This will convert the Quick Mask into a Selection Marquee. You can not use this refined Selection Marquee to cut or copy the selected picture area into another photograph or do any PhotoShop editing or filter operation in that selected part.
The Montage Tutorial contains a detailed description how to use Extract.