Hướng dẫn sử dụng Coreldraw x5 - part 76 ppsx

Exporting Your Composition to Bitmap Format One of the terrific things about designing using a computer application is that you can repurpose a good design. A good design such as the front cover of the catalog just discussed can yield several different uses from only one investment in time—and from knowing how to export the design. Although CorelDRAW is a vector drawing program, it can create a bitmap copy of photographs, a bitmap from photos combined with vectors, and it can export vector art only—text, graphics, anything is fair game. When vectors are copied out of CorelDRAW as bitmaps, a process called rasterizing is performed; CorelDRAW examines the vector artwork at the size and resolution you specify and then uses anti-aliasing (unless you specify no anti-aliasing) to create a bitmap that looks as good as what you see onscreen in your CorelDRAW document. Let’s say you want to feature on your website the front cover of the company catalog. This narrows your export choices down to GIF, PNG, and JPEG (see Chapter 28 for more details on web content creation and exporting). Let’s briefly run through exporting the composition to JPEG now (exporting bitmaps is covered in detail in Chapter 24). Saving a Bitmap Copy of Your CorelDRAW Composition 1. In the Object Manager, unlock Layer 1 by clicking the pencil icon to remove the red slash mark. With the Pick tool, drag a marquee from outside the top left of the design to the bottom right. Doing this is simply a good practice for exporting designs: if there had been a hidden object or one outside of your workspace view, CorelDRAW’s export filter would not include it in the bitmap version it rendered. 2. Many web browsers expect pictures to be in the sRGB color space. Change the document’s color space to sRGB by clicking Tools| Color Management | Document Settings. In this dialog, check “Convert document colors to new color profiles,” and choose sRGB IE61966-2.1 in the RGB list. 3. Click the Export button on the property bar. 4. In the Export dialog, choose JPG-JPEG Bitmaps as the Save As Type from the drop- down list. Check the Selected Only check box, type a name in the File Name field, use the directory pane to choose a location for the export, and then click Export. 734 CorelDRAW X5 The Official Guide 5. You have the option to select a preset export for JPEGs by choosing from the Preset list at top right, but this doesn’t teach you anything. First, set the Color Mode to RGB—JPEGs are increasingly used today for commercial printing, but it’s the wrong color mode for the Web and for email attachments. 6. For starters, set the Compression to 80% (the Quality setting is at High). Choose the Hand tool and use your mouse scroll wheel to zoom in or out of the preview window. Using 50% (Medium) compression produces a smaller file—which is reported at the bottom left of the dialog, but this image shows some JPEG artifacting (noise, corruption) at 50% and not very much at 80%. 7. Uncheck the Embed Color Profile box. Doing this saves in this example more than 500 bytes (about half a K) in file size. Also, web browsers today largely “expect” sRGB color profiles, and Adobe RGB is the current color space for the LUX CorelDRAW layout. If you uncheck the Embed Color Profile option, current browsers such as Firefox and Internet Explorer will display the image as expected. Apple Safari does read color profiles, but if it finds none, it defaults to the Web standard of sRGB. 8. Check Optimize to save on a few K of exported image. 9. Choose Pixels as the Units, and then choose 96 as the Resolution for export. The resolution is meaningless for screen documents, but 96 provides you with a benchmark by which you can calculate the absolute height and width of the exported image—in pixels. The layout’s original size is a little large for the Web and for the reading pane in mail readers such as MS Outlook; type 700 in the Height field to reduce both the Height and Width of the export. 10. The estimated download time shown at bottom left is calculated based on a hypothetical Internet connection you specify by selecting from the drop-down list toward the bottom center of the dialog. By default, it’s set to fast dial-up, which represents an estimated 75 percent (and shrinking) of the United States, but Europe and many other countries are almost entirely on broadband in 2010. ISDN (dial-up) essentially plays to the lowest common denominator—it’s the worst speed you can use to estimate how your audience receives your image files. Therefore, 6.2 seconds—and almost certainly less time for most audiences—is acceptable. Click OK and your work is exported to JPEG file format. CHAPTER 23: Bitmap Boot Camp: Working with Photographs 735 23 Ill 23-10 11. Close the document without saving it. If you save it now, you’ll change the document’s color space for print output. If you’re feeling a little jazzed after reading this chapter, get a friend to pat you on your back, because you deserve it. You’ve taken a serious detour in your “CorelDRAW is a drawing program” education and vaulted right into the arena of design professionals who integrate photos and vector artwork on a daily basis. You now know how to scale an image, to check to see whether its resolution is sufficient to pull a good print, to color-correct both RAW images and regular ones, and how to export your work so friends you’d like to send an email attachment to can see it without necessarily owning CorelDRAW—and the composition is web-worthy, to boot. This is not the complete story of CorelDRAW and bitmaps. You’ll want to do things as special as you do with vectors, so Chapter 24 covers more advanced bitmap-editing techniques, converting bitmap art to vector art, and working with transparency to better integrate bitmap and vector objects in a composition. Read on and see how to create exactly the effect you need for tomorrow’s assignment at work. 736 CorelDRAW X5 The Official Guide Fairly low connection speed Estimated file size/ download time Compression versus quality Color profile Pixels are absolute measurements. Set to RGB CHAPTER 24 Advanced Photography Techniques with CorelDRAW 737 B ecause people seldom photograph an object or a scene with exactly the elements they want in a composition, the field of retouching has thrived since the day a professional had something to sell using a photograph! This is why professionals trim photographs, and so can you by using the CorelDRAW features covered in this chapter. As objects, photographic areas that have been carefully cut out can be composited with other photos and vector shapes to add a whole new dimension to your posters, flyers, and fine art. Additionally, this chapter demonstrates Corel PowerTRACE, part of CorelDRAW; you’ll learn how to create a vector copy of a bitmap so you can scale and rotate it, edit it, and never lose details or resolution as bitmap images are prone to do. Download and extract all the files from the Chapter24.zip archive to follow the tutorials in this chapter. Cropping a Placed Photograph You can perform two types of cropping on placed photos: destructive (permanent) and nondestructive (you can undo what you’ve done). The Crop tool on the toolbox performs destructive cropping. Unless you press CTRL+Z to undo a crop you don’t like, you’re stuck with your crop, and no areas exterior to the image remain that you can expose later. Some users prefer this; you’ll learn both methods in this section. To crop a photo: 1. Bitmap images—for example, photos, paintings done in Corel Painter, and just about any picture off the Web—need to be imported; you do not use File | Open. Choose File | Import, click the Import button on the standard toolbar, or press CTRL+I. In the directory window, scout down the image that you want to place a copy of, and then click Import. Because you’re importing (“placing”) the image and not opening it, you’re always assured that you’re not altering your precious original photo. 2. You define the area you want to crop by click-diagonal dragging the Crop tool from one corner to the opposite corner. 3. You can redefine the crop by click-dragging the resulting bounding-box markers. The corner markers scale the proposed crop area proportionately, while the center markers are used to resize the proposed crop area disproportionately. 4. You can rotate the crop box, which is handy if you want an artistic crop or just want to straighten a horizon in the photo. To do this, first click inside the image; doing this puts the crop area into Rotate mode. Then drag a corner double-headed-arrow marker to rotate the crop. This doesn’t rotate the photo itself, but rather rotates the crop area. 5. Double-click inside the crop area to finish the crop. Figure 24-1 shows the elements you work with onscreen to crop a bitmap image. 738 CorelDRAW X5 The Official Guide To quickly see the resolution of a placed bitmap image, select the bitmap and look at the status bar, which displays the file, its color mode, and its current resolution. The rule is: as a bitmap’s dimensions increase, its resolution decreases proportionately. Nondestructive Cropping In a nutshell, if you want to hide an area of a photo and not delete it as you do with the Crop tool, use the Shape tool. Try this out with the Macaw.jpg image by following the steps in the tutorial. Using the Shape Tool to Crop 1. Create a new (default-sized) document with landscape orientation. Place the image of the Amazon Macaws in a new document by clicking the Import button on the property bar and then selecting the image from the location you downloaded it to. With the loaded cursor, click-diagonal drag to place the image so it fills most of the page. CHAPTER 24: Advanced Photography Techniques with CorelDRAW 739 24 FIGURE 24-1 The Crop tool eliminates the exterior image areas of your defined crop area. Click-drag Scale crop box proportionately Scale crop box disproportionately Rotate crop box Crop tool 2. Choose the Shape tool. Notice that the photo, which is still selected, now has control node markers at each corner. These markers behave and operate exactly like control nodes for vector shapes. 3. Just for the fun of it, click a node to select it, and then drag it toward the center of the image. This is not what the pros call an “expert crop,” but you’ve just learned something that will come in very handy in your future work. When you drag a node inside of the outside dimensions of a placed photo, the two sides that meet at this node hide areas of the photograph. Press CTRL+Z to undo this, and now perform a more practical crop. 4. Click-drag so that you’ve marquee-selected two neighboring nodes; they can make up a horizontal or vertical edge of the photo. For this experiment it makes no difference. 5. Use the keyboard arrows to nudge the nodes toward the center of the image. Hold SHIFT to super-nudge the nodes if you like. This is how you can nondestructively crop a placed photo; nudge the nodes in the opposite direction now—you’ve hidden and then unhidden one dimension of the photograph. 6. With two nodes selected, hold CTRL and then drag the nodes toward the center of the photo. The CTRL key constrains movement so the edge you’re cropping remains parallel to the dragging page. Masking Through Nondestructive Cropping Go to the head of the class if you’ve already discovered that you can add control nodes to a placed photograph with the Shape tool! CorelDRAW “sees” a bitmap as an object that has a fill—specifically, a bitmap fill. Therefore, this object can be shaped and reshaped by adding nodes and also by changing the segment property between nodes. The following sections take you through some advanced bitmap editing to trim around a photograph so it becomes a floating object in a composition. Trimming Away Unwanted Image Areas What you’ll learn in this section goes way beyond the simple cropping of an image. You’re going to trim the background away from an image of a bust of classical composer Johann Sebastian Bach, put a new background behind the bust, and by the end of this section, you’ll have designed a concert poster. There are two nondestructive methods for removing the background from a photo’s subject, and both techniques are described in this section. The elements of the poster have already been created for you, and by working through the tutorials, you’ll see how to make a design with elements in front of and behind each other, just like you do with vector shapes, but using photographs. To begin at the beginning of this poster design (call it an overture), you need to create a new document (portrait orientation, default page size) and then to place the image of Bach— a little smaller than the page size, but he can be scaled at a later time when needed—to use the Shape tool to trim out the background. 740 CorelDRAW X5 The Official Guide Background Removal, Technique 1 1. Click the Import button on the property bar, and then in the Import dialog, locate JS Bach.tif, select him, and then click Import. 2. Your cursor is loaded with the image: click-drag, as shown in Figure 24-2, and then release the mouse when the cursor reports that the height for the placed image will be about 9 inches. 3. Choose the Shape tool. Begin by clicking the top right node of the image, and then click-drag it toward the center of the image until the top and right edges of the image touch the bust of Bach, as shown next. Clearly, you’re not going to get where you want to go with only four control nodes, because the geometry of the bust is far from CHAPTER 24: Advanced Photography Techniques with CorelDRAW 741 24 FIGURE 24-2 Scale and place the image by click-diagonal dragging your loaded cursor. Click-diagonal drag to size and place. perfectly rectangular. This is okay; you’ll add nodes to the outline of the image in the following step. Ill 24-1 4. With the Shape tool, click a point on the outline of the photo where there should be a change in direction of the line; Bach’s powdered wig near his forehead is a prime area. Now, either double-click the segment, press the keyboard plus (+) key, or click the Add Node button on the property bar to add a node. While you’re in the vicinity of Bach’s forehead, several additional points will be needed. A quick way to add points in-between existing points is to repeatedly click a point and press the + key. 5. Click-drag points so they visually coincide with the vertices of Bach’s wig. It’s okay if the lines between the nodes hide areas you want exposed. 6. Click a straight line segment that should curve away from the photo. Then click the Convert To Curve button on the property bar. The segment can now curve; click-drag the segment away from the photo, as shown next, until you can see Bach’s locks. You can also right-click a segment and choose To Curve from the pop-up menu. 742 CorelDRAW X5 The Official Guide Click-drag Ill 24-2 7. That’s it; all it takes now is about 10 minutes of your time to work around the profile of the bust, hiding areas and creating curve segments where needed. Yes, it’s a lot of work; so is putting on a tuxedo or gown to go and collect an industry award for outstanding design work (prompt, hint, encouragement!). A good thing to do once you’ve trimmed away the non-essential Bach, because the default color of the page is white, is to put a colored vector shape behind your work to check your edge work. As you can see here, the example looks pretty good; a rectangle was created, filled, and then rotated, and then SHIFT+PAGE DOWN is pressed to put the rectangle to the back of the page’s layer. Ill 24-3 CHAPTER 24: Advanced Photography Techniques with CorelDRAW 743 24 Add Node Convert to Curve . curve; click-drag the segment away from the photo, as shown next, until you can see Bach’s locks. You can also right-click a segment and choose To Curve from the pop-up menu. 742 CorelDRAW X5 The. from CHAPTER 24: Advanced Photography Techniques with CorelDRAW 741 24 FIGURE 2 4-2 Scale and place the image by click-diagonal dragging your loaded cursor. Click-diagonal drag to size and place. perfectly. double-headed-arrow marker to rotate the crop. This doesn’t rotate the photo itself, but rather rotates the crop area. 5. Double-click inside the crop area to finish the crop. Figure 2 4-1 shows