tailieunhanh - Photoshop cs5 cho nhiếp ảnh gia part 29

Sử dụng sàng lọc Edge Controls Các công cụ sàng lọc Edge (Hình 4,29) đã được hoàn toàn đại tu tại CS5 để làm cho nó thậm chí còn mạnh hơn và dễ dàng hơn để sử dụng. Mục đích của nó là để cho phép bạn sửa đổi các cạnh của một sự lựa chọn để nó pha trộn hoặc tách từ các nền khi cần thiết. | detailed areas we can make reasonably accurate selections in many cases as shown in Figure . Figure It was easy to make a reasonably good selection of the penguin by using the Quick Selection tool. We ll need to use Refine Edge covered in the next section to perfect the selection of the tail. If the selection is not updating fast enough you may need to drag a little more slowly and continue to hold down the mouse. If you stop dragging and then click elsewhere the tool will automatically change to Add to Selection. The selection will grow to incorporate the new area but not necessarily areas in between the original selection and the new area. To remove an area from the selection choose the Subtract from Selection option in the Options bar and then drag over the area to be removed. You may need to reduce the size of the tool. In areas of lower contrast you may need to alternate between adding to and subtracting from the selection. Holding down the Alt Option key will enable you to rapidly toggle between the two modes. As you do so Photoshop is actually refining the algorithm to make the selection more accurately and quickly. To further adjust the edges of the selection click the Refine Edges button discussed in the next section. Using the Refine Edge Controls The Refine Edge tool Figure has been completely overhauled in CS5 to make it Photoshop even more powerful and easier to use. Its purpose is to enable you to modify the edges ONLY of a selection so that it blends with or separates from the background as needed. When using the selection tools a Refine Edge button appears on the tool Options bar . It s also available from within the Masks panel from the Mask Edge button. It is our method of choice for controlling the appearance of the edges of a selection no matter how we made the initial selection. It s taken the place of the simple Feather command in our workflow and it eliminates the need for the elaborate procedure we used to use in which we .