VIEWS: 73 PAGES: 11 POSTED ON: 5/19/2010
Using Adobe Photoshop (version 7) to Edit Scanned Images Tutorial Exercise One - Basics For this exercise you will start with a scanned photograph and make typical kinds of adjustments. You will learn to use a variety of tools & functions including • Crop, Measure • Rotate • Zoom Tool • Variations 1. Open Adobe Photoshop Start Programs Adobe Photoshop 7.0 2. Open the picture of a girl and her ball -- file name <photo_album_scan.jpg> located on the desktop. File Open Desktop > Adobe Class > Exercise 1 Photo_album_scan.jpg 3. Working with the picture. Before doing any adjustments to the picture use the Save As command and save the picture to the desktop with the file name <girl&ball.jpg> using default settings. The picture has been scanned upside down along with another picture that was on the same page. We are going to select and crop the picture of the girl. HINT: When scanning a picture from a book it sometimes helps to put a black sheet of paper behind the page to avoid any bleeding through. a) Click on the Crop Tool. b) Drag from the upper left corner of the picture of the girl to the lower right corner. c) Press the Enter key to Crop the selected image. d) If you did not select well, use the Edit / Undo command and select again. e) The scanned picture is slightly crooked. Use the Measure Tool to straighten the photograph. Click and hold on the Measure Tool and drag from the lower left corner to the lower right corner. Try to drag along the edge as precisely as possible. (The Measure Tool is located under the Eyedropper Tool. A > in the lower corner of any tool indicates additional tools are available. Click and hold on the tool to see more options. ) 1 f) From the menu select Image >Rotate Canvas >Arbitrary. Click in the radio button CW for clockwise rotation. Click OK to rotate the picture. g) Crop the picture again; this time make a selection that is just inside the border of the picture. h) To flip the picture right-side-up choose Image > Rotate Canvas, then 180. Now the girl is right side up. i) Choose File > Save Correcting the Exposure and Color Balance When correcting for exposure and color its helpful to have the original picture in font of you. Since we do not have the original picture use your best judgment. The scanned picture looks very dark. 1) Use the Zoom Tool to make the image 100%. Click on the Zoom Tool, then click on the image. Every time you click with the Zoom Tool the image gets a little larger. To reduce the size of the image, hold down the ALT key (note that a minus sign appears in the center of the magnifying glass), and Click to reduce the size of the image. 2. From the menu choose Image > Adjustments > Variations. The Variations window appears. a) The two picture in the upper left are the original (note: you can click the original to reset the image) and the Current Pick (what the picture looks like with adjustments). b) The three pictures to the right adjust for brightness and include the options for Lighter and Darker. The Current Pick in the center reflects the change for lighter or darker. c) The seven pictures in the center adjust for color and provide a way to correct color with the Current Pick in the center The pictures surrounding the Current Pick allow for adjustments and show how the picture would look if you changed a color level in that direction (for example, More Green, More Yellow, More Cyan, More Red, More Blue, More Magenta) You can also effect Shadows, Midtones, and Highlights, and allow for more or less Saturation by using the radio buttons. EXPERIMENT with these features. Be sure the <girl&ball> window is the active window before proceeding. If it is not, then close the Variations window, click on the <girl&ball> window and then re-select Image > Adjustments > Variations. 3. Adjust brightness by clicking on the pictures labeled Lighter and Darker on the right-hand side. Keep comparing the Current Pick (top row) to the reference picture. 4. Adjust color by evaluating whether any of the color variations are closer to the colors of the reference picture. Pick a color variant or stick with the current setting. Use you own judgement and color sense. 5. Click OK when you are satisfied with color and brightness. This closes the Variations window. If you are not happy with your choices, then choose Edit > Undo Variations and start over again or you can click on the original picture in this window. 2 6. Another way to do these adjustments is to select Image > Adjustments> Auto Levels and allow the system to make the adjustments for you. Sometimes this is adequate and sometimes not. Again, just use your color sense. Brightness/Contrast Increasing contrast makes the light areas lighter and the dark areas darker; decreasing it makes the light areas darker and the dark areas lighter. From the menu select Image >Adjust >Brightness/Contrast Click on the slider to adjust the <girl&ball> picture. Experiment. When you are satisfied with the look then click OK and Save your work. 3 Tutorial Exercise Two- Retouching Photos Open the photograph of the gondola. File Open Desktop Adobe Class Exercise 2 Start06.psd 1. Choose File > Save As > Gondola 2. Crop the image Select the Crop Tool. Drag to select an area around the image. 3. Straighten the image • Move the pointer outside the selected area and "swing" clockwise until the crop box is parallel with the image. • Use the pointer to fit the crop box to the picture. Drag in and out on the crop box handles to accomplish. • Press ENTER key to crop and straighten the picture. 4. Adjust the tonal rang The tonal range of an image represents the amount of contrast or detail in the image. Choose Image> Adjustments> Levels Notice the histogram in the dialog box. The black triangle represents the shadows while the white triangle represents the highlights. This graph indicates that there are no very dark or very light colors. You can adjust the black and white points of the image to extend its tonal range. Drag the dark and light triangles inward to where the histogram indicates the darkest and lightest colors begin. Click OK to apply the change. 5. Choose File > Save Shadows Midtones Highlights (black) (grays) (whites) 4 6. Removing a color cast (or imbalances of color) You will use Color Balance to correct the color cast. Choose Image > Adjustments > Color Balance Drag the top slider to the left (-15) Drag the middle slider to the right (+8) Click OK to apply the changes to the Color Balance. EXPERIMENT with the various choices including the Tone Balance. (Shadows, Midtones, Highlights) Having Preview checked allows you to view changes to the picture as you work. 7. Choose File > Save Replacing colors in an image Options in the Replace Color command's dialog box allow you to adjust the hue, saturation, and lightness components of a selected area of the image. It helps to zoom in on the area where you want to effect a change. In this case, you want to change the color of the tarp in the gondola in the bottom right corner of the image. a) In the Layers palette, select the Background. b) Use the Zoom Tool to zoom in on the tarp. c) Select the rectangular marquee and drag around the tarp. d) Choose Image > Adjustments > Replace Color e) Click the left eyedropper tool in the Replace Color dialog box, and click once on the orange tarp to select it. f) Then select the center eyedropper-plus tool, and drag over the other areas of the tarp until the entire tarp is highlighted in white in the dialog box. g) Make the following adjustments: Fuzziness = 61 ; Hue = 149 ; Saturation = -17 ; Lightness = -39 (Note that the color displays in the sample square. For different colors, experiment with different settings.) Click OK to apply changes. h) Choose Select >Deselect i) Choose File >Save. 5 Adjusting saturation with the sponge tool When you change the saturation of a color, you adjust its strength or purity. The Sponge Tool is useful in letting you make subtle saturation changes to specific areas of an image. We will use the sponge tool on the red and white stripped tarp covering the main gondola in the picture. 1. Hold down the mouse button on the Dodge Tool and select the Sponge Tool. 2. From the Sponge Options tool menu choose Mode: Saturate from the pull-down menu. Set the intensity of the saturation effect to 90% using the Pressure pull-down menu (or use the slider). 3. Select a soft round 17 pixels brush from the Brush: pull-down menu. Then drag the Sponge Tool back and forth over the gondola to saturate the color. (You can use Desaturate to reverse the process.) Adjusting lightness with the Dodge Tool Use the Dodge Tool to lighten the highlights along the gondola's hull and exaggerate the reflection of the water there. 1. Select the Dodge Tool (its under the Sponge Tool) 2. Choose Highlights from the pull-down menu in the Dodge Options palette; set Exposure to 50% 3. Select a soft round 13-pixel brush from the Brush pull-down menu. 4. Drag the Dodge Tool back and forth over the gondola's hull to bring out its highlights. 5. When pleased with results choose File > Save Removing unwanted objects Use the Clone Stamp Tool to remove an object or area by "cloning" an area of the image over the area you want to eliminate. 1. Select the Zoom Tool; magnify the small motor boat in the center of the picture. 2. Select the Clone Stamp Tool 3. In the Clone Stamp tool bar make sure that the Aligned option is deselected. 4. Select Stamp size from the Brush pull-down menu. 5. Center the Clone Stamp Tool over the water between the large gondola and the post to its right. 6. Hold down the ALT key and click this section of water. 7. Drag the Clone Stamp Tool over the boat to paint over it with water. 8. Choose File > Save 6 Replacing part of an image The sky is fairly drab and overcast in this photograph. You will replace it with a more interesting sky from another file. 1. Select the Magic Wand Tool. Click to select part of the sky. 2. Hold down Shift key and click the rest of the sky to select it. 3. You will now open another file that is just a picture of clouds. Select File > Open > Desktop > Exercise 2 > Clouds.psd 4. Choose Select > All; then choose Edit > Copy. Close the Clouds.psd file. 5. Return to the picture of the gondola. Choose Edit > Paste Into to past the clouds into the current selection. Notice that a new layer has been added to the Layers palette. 6. Use the Move Tool and drag the clouds into the position you want. 7. Change the Opacity of the cloud layer to 55% using the Layers Palette. A lower percentage will soften the look of the clouds; a higher percentage will make the clouds stand out. 8. Choose File > Save Adding Text • Select the Horizontal Type Tool (T) • Click the gondola image in the upper right corner • Note that a text layer now appears in the Layers Palette. • Font and font size and color selection choices appear in the "T" tool bar (reproduced below). • Type Venice Is the Place. The text is automatically placed on the picture. • Reposition the text using the Move Tool. • Notice that the Layers palette now includes a layer named Venice with a T icon next to the name, indicating it is a type layer. Adding a Layer Style • From the Layer menu select Layer Style • Select Blending Options • EXPERIMENT by clicking in the various boxes and making choices. 7 You will now want to flatten the image into a single layer. 1. Choose Layer > Flatten Image 2. Choose File > Save As. In the dialog box, type a new filename <gondola2>, select the appropriate Format (jpg, tif, pict, etc.) and click Save. Applying the Unsharp Mask filter The last step you take when retouching a photo is to apply the Unsharp Mask filter, which adjusts the contrast of the edge detail and creates the illusion of a more focused image. 1. Choose Filter > Sharpen > Unsharp Mask 2. Be sure the Preview option is selected 3. Drag the Amount slider until the image is as sharp as you want (try 120%); then click OK to apply the Unsharp Mask filter. Experiment. 8 Working with a LOGO The goal in this short exercise is to take a logo and make a modification to it. As an example, we will use the U Caduceus logo and add a circle around it. Go to the Health Sciences Center Office of Public Affairs image gallery page at: http://www.med.utah.edu/pubaffairs/imagegallery/ Scroll until you see the U Caduceus. Right click on the U Caduceus image and Save Image As … Save image to the desktop as U_Caduceus.gif Open PhotoShop and navigate to: File > Open > Desktop > U_Caduceus You notice that you don’t have any room on the canvas for drawing. To create more canvas - Image > Canvas Size Change the Width and Height to 4 inches and then press OK. This gives you an area when you can draw or type text. Use the Eyedropper Tool to select the red color from the logo and use as the foreground color. Select the Elliptical Marquee Tool – hold down the Shift key and then draw a circle around the logo. You can move the circle for better placement – just click on the circle and drag. Proceed - Edit > Stroke Width 5 Click OK Select > Deselect File > Save or Save As 1. (Note: If you want to save the image as a jpeg, then do Image > Mode > RGB Color before saving.) 9 Resolution Image Resolution--the number of pixels per unit of length in an image; measured in pixels per inch (ppi). An image with a high resolution has more pixels and therefore a larger file size. Monitor Resolution--the number of pixels per unit of length on a monitor; usually measured in dots per inch (dpi). Printer or Output Resolution--the number of dots per inch produced by an imagesetter or laser printer. Higher resolution printers combined with higher resolution images generally produce the best quality. Photoshop Tools Go to Adobe Online ..…......... Rectangular Marquee..…….... ..... Move Lasso .......................……....... ..... Magic wand Crop ......……...........……...... ..... Slice Healing Brush .….......…........ ..... Brush Clone Stamp ......…...……..... ..... History Brush Eraser .........................…........ ..... Gradient Blur ............................…....... ..... Dodge/Sponge Path Component Selection.... ..... Horizontal Type Pen .................……………... ..... Rectangle Notes .......................….......... ..... Eyedropper Hand………………………... ..... Zoom Set Foreground color ............ Default colors ...........…......... …. Set Background color Edit in Standard mode .......... ..... Edit in Quick mask mode ..... Full screen with menu mode or full screen …. Jump to ImageReady 10 File Formats Bitmap -- Use the bmp. file extension. Used for photographs, scanned images and images saved in "paint" programs. Bitmap images tend to have larger file size. And it is best not to rescale a bitmap image as it effects the definition of the image. Can be used on Macintosh or Windows. (See http://www.whatis.com/bitmap.htm for a slightly more technical definition.) GIF -- Use the .gif file extension. Graphics Interchange Format. Use GIF file format for images with only a few distinct colors, such as illustrations, cartoons, and images with blocks of color, such as icons, buttons and horizontal rules. A popular file format for the Web. (See http://www.whatis.com/gif.htm for a slightly more technical definition.) JPEG -- Use the .jpg file extension. Joint Photographic Experts Group works well for Web graphics. Use JPEG for scanned photographs and naturalistic artwork with highlights, shaded areas, and shadows. The more complex and subtly rendered the image is, the more likely it is that the image should be saved or converted to JPEG. DO NOT use JPEG for illustrations, cartoons, lettering or any images that have very sharp edges. Sharp edges in images tend to blur in JPEG. (See http://www.whatis.com/jpeg.htm for a slightly more technical definition.) PICT -- Use the .pct file extension. The Picture file format is used primarily on the Macintosh platform; it is the default format for Macintosh image files. PICT files are usually large. Use the PICT format for images used in video editing, animation, desktop computer presentations and multimedia authoring. Not used that much anymore. Photoshop --Use the .PSD file extension. TIFF--Use the .tif file extension. The Tag Interchange File Format is compatible with a variety of software applications and can be used across platforms such as Macintosh, Windows and UNIX. TIFF format is complex and the files are generally larger than GIF or JPEG. Cannot be opened by a browser. There is no compression with TIFF and so this is the best format if you are going to have your work printed professionally. TIFF files are commonly used in desktop publishing, faxing, 3-D applications, and medical imaging applications. (QuarkXPress on Mac) To place an image in any of the following software programs used the suggested file extension: • Microsoft Word - save as JPEG or TIFF • PowerPoint presentations - save as JPEG or TIFF • QuarkXPress (desktop publishing) on the MAC - save as TIFF • WordPerfect - save as JPEG or TIFF revised Feb 15, 2006 - jml 11
"Adobe Photoshop Tutorial and Exercises - Using Adobe Photoshop "