Adobe Photoshop Tutorial. Copyright Michael B. Karbo.
15. The Extract tool
Let us return to the main subject for this part of the booklet, which is selection and free scraping. Now we will introduce you to a new tool; that is Extract.
Extract is not a traditional selection tool like the lasso. Extract works in quite a different way, but the function is a good all-round tool for free scraping especially in motifs with fuzzy edges.
In practice extract works similar to a user firendly combination of a number of other tools (magic wand, lasso, eraser etc.) but yet it is quite different. You will soon learn to highly appreciate this tool. At least it is experienced as more ”calm” and less ”stressing” to make a larger selection with Extract as compared to various lassos.
Introduction to Extract
In this exercise you will try to use the Extract tool on a relatively large figure, which would be laborious to scrape free with a lasso tool. The figure works easily with Extract, since it has well defined edges.
1. On the home page for this booklet you can find the picture sapiens1.jpg. Retrieve that and open it in Photoshop. Save the picture right away as sapiens1.psd.
2. This is an old anatomical drawing. The body now has to be scraped free. Choose menu items Filter --> Extract. That opens a large dialog box:
3. In the left side of the dialog box you see a number of different tools, which you use for the extraction (see Figure 26).
4. The individual tools can be set in the right side (or in some instances from the keyboard).
5. Now select to zoom ind so you see the head in a good enlargement. You can use the Zoom tool (click with the magnifying glass), or you can press Control++ a couple of times, until you get suitably cose in.
6. Use also the hand tool (mouse drag with the space bar) to navigate in the picture, so you see the head. The exercise continues in the next section.
Figure 26. The Extract function has a number of tools, each of which can be activated with shortcut letters.
Select the edge
Now you are going to select the whole figure.
1. You have zoomed in on the figure’s head. Select Edge Highlighter Tool in the upper left:
2. Then choose a suitable brush size in the right side of the window. Enter 6 in the Brush Size field:
3. Make sure that you have checked the Smart Highlighting field – that gives the same effect as with the magnetic lasso (see page 45).
4. Now paint calmly along the edge of the figure. It will take some time to get all the way around; but you are in no hurry, and it is not difficult:
5. When you get to the edge of the picture area, hold the space bar down and drag with the hand tool until you have a fresh section to work with.
6. Note: you do not have to work in one long continuous move. That is a great convenience. You can easily take a break on your way and rest your hand.
7. If you make an error, just hold the Alt key down and erase the erroneous area. Continue this way until you reach all the way around.
8. It might be hard to select close to the figure’s hands and feet, since you can not see the contour well. But it is not important for now if the selection is not perfect. Rather take a little more time than not enough.
9. When you finish your way around, you can doubleclick on the button for the hand tool. Then you see the whole picture again.
10. Now click on the Fill tool:
11. Place the cursor in the middle of the figure and click. The area inside the green selection is now covered with a blue color, indicating that this area is to be preserved:
12. You are now ready to remove the background. Click on the Preview button:
13. Then the background is removed. But the picture is not finished; this is a temporary free scrape. You can still fine tune the details.
Fine tuning before final extraction
Now the figure has to be carefully examined. Among other things that involves the areas around hands and feet, but the whole edge has to be checked.
2. Click on Cleanup Tool:
3. The tool works this way: When you paint along the edge, you remove parts of the motif. If you simultaneously hold the Alt key down, you reconstruct the original figure.
5. You can adjust how weak or strong the effect will be by entering a number between 1 and 9. The mouse button must not be depressed while you enter the number, and you can not see that anything happens. But if you press 1, the tool only works very weakly. Try to start with the value 6.
6. Now work the whole edge with a critical eye. Use the tool close to the contour with the Alt key down on the inside of the figure. Use it without the Alt key on the outside of the figure.
7. Adjust the brush size as needed. When you get to the left hand, you need to use a quite small brush (size 1,2 or 3) to free the fingers:
8. When you are satisfied with the result, you click on OK. Then save the image file again.
Figure 27. The extraction is complete.
Composition with adjustment of colors
We hope that you managed to free scrape a really splendid figure. Of course it will be used in a new composition.
1. You still have sapiens1.psd read into Photoshop. Now open the image file la_defense.jpg, which can also be retrieved from the home page for this booklet. That is a photo of a cold and modern city environment, in which we need to place our human body.
2. You now have two open image files. Switch to the picture sapiens1 (with Control+F6).
3. Choose the function Auto Contrast:
4. Then the colors get much better for our purposes. Save the file sapiens1.psd with the new color adjustment (press Control+s).
5. Now select everything in the picture with Control+a and make a copy with Control+c. Shift to the other picture, la_defense, and insert the copy there with Control+v.
6. The copy is inserted in a new layer. Now you need to save the image file. Try to press Control+s.
7. You would normally expect that the file la_defense.jpg is saved, but that is not the case. That is because there is more than one layer in this picture, and that is not possible in the JPEG format. In stead save the file in the Photoshop format as la_defense.psd.
The body is too large relative to the rest of the picture. It needs to be scaled.
1. So press Control+t to make a so-called free transformation. The figure gets equippped with handles in all corners, and they can be used to scale and transform the figure in different ways.
2. Here we just need to reduce its size. So hold the Shift- key down, and drag in the upper right corner handle. Drag the figure down to a size like this:
3. Press Enter to finish the transformation, and the figure gets the new size. Notice that this retains the figure’s proportions when you use the Shift- key while scaling; its proportions are not distorted.
4. You need to insert yet another figure. Select the one you inserted with Control+a. Don’t let it confuse you that you apparently select the whole picture area. Since the figure is the only picture content, only that is selected.
5. Make a copy (with Control+c), and insert that (with Control+v). That results in a third layer in the picture:
6. The new figure needs to be mirrored. The layer is selected. Press Control+t to activate the ”Free transformation” function. The figure gets equipped with 8 handles, in whih you can drag with the mouse.
7. Drag in the middle handle on the frame’s right side. Drag towards the left; drag all the way across the figure:
8. Drag until the figure’s frame has about the same size as before. Then release and press Enter. The the figure is mirrored.
9. Use the Move tool to place the two figures as shown below. Save the image file again. Now you are finished with this picture.
Figure 28. A composition in three layers.