Trượt màu dừng lại với các giá trị ban đầu đo cho các thành phần Red. Trong ví dụ, di chuyển dừng Vị trí 75% đến 89%, Vị trí 50% dừng lại để 51%, và 25% Vị trí dừng lại để 22%. 20. Kích hoạt điều chỉnh Bản đồ Green, và nhấp vào hình thu nhỏ Gradient Map. | isolating image elements 191 Figure The gray area of this figure shows the area that should be filled when you have completed step 11. The black fill in the Plant Selection layer should not cover any of the flowers and it should have a slightly soft edge. Later we will use this content to load a selection and make short work of the image adjustment. Making a Selection of the Object Calculations A second way to select the lily is by helping to define the selection of the shape with calculations. This section does not follow from the previous one but substitutes for it. You may find a number of ways to do something similar to what is suggested here using calculations. The idea is to take whatever advantages you see in the image successfully make an enhancement to get the result you need and lessen the amount of work you have to do manually. The lily is the brightest element in the image and that generally makes it a pretty easy target for this kind of selection and open to a lot of other possibilities. For example you might just be able to use the Threshold tool to define most of your selection. In a similar way the darkest most saturated least saturated or most color-defined image areas can all provide the information you need to make a calculated selection depending on the separations you choose to make the image you are working on and what you want to achieve. We ll look to a calculation to bring out your result in a way that is partially specific to this image. 1. Starting with the image make an RGB separation by using the RGBL Components Only tool under the Power_Separations category in Effects. 2. View all the components and then delete the Blue component layer. You won t need it for this calculation because it offers very little practical distinction in the object you are trying to separate. However take a look at it to see why it isn t helpful. 192 chapter 7 Altering Composition Figure The basic image components split out as shown .
