Tự học Photoshop

Image correction made easy with the Levels command Does your photo look dull, lacking contrast? Or, does it have a color cast? Is it reddish or greenish? Adobe Photoshop's Levels command lets you correct the tonal range and color balance of an image by adjusting intensity levels of the image's shadows, midtones, and highlights. In this tutorial, you'll learn how to adjust the tonality and color in your images using the Levels command. 1. Open an Image in Photoshop. Choose File > Open or double-click a thumbnail in the File Browser. Before you start making adjustments, evaluate the image tonality. Is it too light or dark? Does it have too much or too little contrast? Is there a color cast? 2. Create a new Levels adjustment layer. Choose Layer > New Adjustment Layer > Levels, and then click OK in the New Layer dialog box. You can also open the Levels command by choosing Image > Adjustments > Levels. However, with an adjustment layer, you are applying the tonal correction on a separate layer. The original image is untouched. If you decide you don't like your changes, 1 you can change them at any time or simply discard the adjustment layer and return to your original image. A useful tool for evaluating an image's tonality is the histogram displayed in the Levels dialog box. A histogram illustrates how pixels in an image are distributed by graphing the number of pixels at each color intensity level. This can show you whether the image contains enough detail in the shadows (shown in the left part of the histogram), midtones (shown in the middle), and highlights (shown in the right part) to create good overall contrast in the image. 3. Set the shadows and highlights. Move the Black Point Input slider and the White Point Input slider (located directly beneath the histogram) inward from the edges of the histogram. Moving the Black Point Input slider maps all image values at its position or below to the Output Levels black point (set by default to 0, or pure black). Moving the White Point Input slider maps image values at its position or above to the Output Levels white point (set by default to 255, or pure white). For example, if your image is too dark, try moving the Input White Point slider to the left. This maps more values in the image to 255 (the Output Levels white point), making them lighter. 2 4. Adjust the midtones. Move the middle Input slider to the left to lighten the image or to the right to darken the image. The middle Input slider adjusts the gamma in the image. It moves the midtone (level 128) and changes the intensity values of the middle range of gray tones without dramatically altering the highlights and shadows. 5. Remove the color cast. Select the Set Gray Point Eyedropper tool in the Levels dialog box. Click an area in the image that contains only a gray tone, or an area containing as few colors as possible. It's easier to color balance an image by first identifying an area that should be neutral and then removing the color cast from that area. With such a correction, all other colors in the image should be color balanced, too. The eyedropper tools work best on an image with easily identified neutrals. Advanced users often use the Levels command to adjust individual channels and remove a color cast. Choose a channel from the Channel menu of the Levels dialog box and then adjust the Input sliders. 3 Remove red-eye in images There's nothing more frustrating than having a great picture ruined when a person's eyes come out bright red. Adobe Photoshop gives you a simple way to fix red-eye using the Color Replacement tool. In this tutorial, you'll learn how to use the tool to fix red-eye in just a few steps. 4 1. Open your image. Open the image that you want to repair. Try zooming in so you can easily see the red eyes that need to be fixed. Then, select the Color Replacement tool (located in the toolbox with the Healing Brush and Patch tool). 2. Choose a brush tip. Choose a brush tip from the options bar. The brush tip should be smaller than the red area of the eye to make correcting the red-eye easier. 3. Set options for the Color Replacement tool. In the options bar, you can choose settings that help you fix red-eye. For Mode, make sure that Color is selected. For the Sampling option, choose Once to erase only areas containing the color that you target. For the Limits option, select Discontiguous to replace the sampled color wherever it occurs under the brush. Drag the Tolerance slider to a low value (around 30 percent) to replace only the few colors very similar to the pixels you click. 4. Choose a color to replace the red. Typically, black is a good choice, but you could try other colors to more closely resemble a person's eye color. To choose a color, click the foreground color swatch in the toolbox. In the color picker, choose a color that looks good, and then click OK. 5. Repair your photo. Click once on the color you want to replace in the image. Drag over the red with black to repair the image. If all the red isn't removed, try increasing the Tolerance level in the options bar to correct more shades of red. 5 Once you're happy with the correction, save your image. Red-eye will never present a problem again! Create an image using layers When you build an image from different pieces--background color, text, shapes, and photographs--Adobe Photoshop layers give you complete creative control. In this tutorial you'll create a multilayered image, apply a layer mask, and then add a text layer. 1. Open an Image in Photoshop. Choose File > Open or double-click a thumbnail in the File Browser. By default, the Layers palette should show. If not, choose Window > Layers. The Layers palette displays all the layers in your document with the layer name and a thumbnail of the layer's image. 6 2. Convert the background layer. In the Layers palette, double-click the background layer. Click OK in the New Layer dialog. Converting the background into a regular layer lets you use transparency in this layer. You can now view or hide the layer using the eye icon. Click the eye icon on a layer. Notice that the icon disappears and the layer is hidden. Click the empty icon box again. Both the eye icon and the layer's content reappear. 3. Apply a layer mask. A layer mask lets you select and display just the part of the image you want to use, without altering the image. Here we'll mask out all of the image except a circular area of the flower. Click and hold the Rectangular Marquee tool, and then select the Elliptical Marquee tool from the pop-up menu. Hold down the Shift key to constrain the selection to a circle, and then drag an area on the image. In the Layers palette, click the Add Layer Mask icon. Now only the area you selected is visible. You can change the visible area by moving the mask around the image. First click the link icon to unlink the mask from the layer. Select the Move tool, and then click inside the mask and drag to reposition it. Once you have your final position, click the link icon to relink the mask and the layer. Now you can move the layer and the mask will move with it. 7 4. Add a stroke effect. Click the Add a Layer Style button at the bottom of the Layers palette, and select Stroke from the menu. Choose stroke settings in the Layer Style dialog box, including color, size, and position of the stroke. 5. Create a new layer. Click the Create a New Layer button to add a new layer to the image. The new layer is added on top of existing layers and becomes the selected layer. Click the Foreground color swatch and select a color with the Color Picker. Select the Paint Bucket tool (located in the toolbox with the Gradient tool) and click anywhere in the image to create the fill. 6. Reorder the layers. 8 Click the new layer and drag it beneath the lower layer. Changing the stacking order of your layers makes certain parts of the image appear in front of or behind other layers. 7. Add a text layer. In the Layers palette, click the top layer. Select the Text tool, and then click on the image. The text cursor appears. In the options bar, change text size, font, style, or color to your liking.When you add text, Photoshop automatically places it on its own layer, where you can edit it separately from the rest of the image. To edit the text, select it with the Text tool, and then change any of the settings in the options bar. To move the text, select the Move tool and then drag the text. 8. Add an effect to the text. 9 Click the Add a Layer Style button and select Drop Shadow from the menu. You can change the color or angle of the shadow or make other adjustments in the Layer Style dialog box. In the Layers palette, the layer effect shows under the layer name. You can turn display of the layer effect on or off by clicking the eye icon next to the effect. Using Photoshop selection tools Having trouble deciding how to select part of your image? Adobe Photoshop gives you several tools that help you target just the areas you need to select. In this tutorial, you'll learn about the best way to use each of the selection tools.You can practice with the eagle image, located in the Photoshop CS/Samples folder. 1. Use the Magic Wand tool to select the background of the image. 10 [...]... letting Photoshop control the color management, then make sure any color management options are turned off Do not apply color management twice to your image Unpredictable print color will result if color management is done with both Photoshop and the printer driver simultaneously 7 Print the image Once all the settings have been made in the printer options dialog box, click the Print button Using Photoshop. .. and Photoshop automatically fits the image to the page You can also manually enter values for the Scale, Height and Width Or, you can grab one of the handles in the preview image and scale the photo 5 Set the color management options and click the Print button Select Show More Options Choose Color Management from the menu in the More Options area Select Document for the Source Space If you want Photoshop. .. Photoshop makes it easy to add shapes to an image: you can draw them using a variety of shape tools, or select from a large assortment of predrawn shapes You can arrange vector shapes on separate layers for easy modification and overlay effects In this tutorial, you'll add both background and foreground shapes to an image and create some flair with gradient and layer effects 15 1 Open an Image in Photoshop. .. you selected with the Magnetic Lasso tool Produce great prints using Print with Preview What's a great way to produce color prints from your inkjet printer? Use the Print with Preview command in Adobe Photoshop The Print with Preview command lets you preview how your photo will print so the results are more predictable You'll learn how to 12 add a simple border around your photo and then transform it... from the Profile menu Click the Print button The Print dialog box closes, and a second Print dialog box opens Color management is essential for producing consistent color when printing Whether you let Photoshop or your printer driver control color management, you'll get the best results using a custom profile for your printer and the specific type of paper you're printing on 6 Specify the printer settings... Shape tool in the toolbox In the options bar, click the down arrow to open the Custom Shape Picker Click the black triangle to open the palette menu and select All, and then click Append This loads all of Photoshop' s predrawn shapes into the Custom Shapes palette 6 Draw a custom shape Now we'll add a custom shape to the foreground for an overlay effect Select the top layer of the image, and use the foreground... resize Select the layer and then use the Move tool to move the shape, or choose Edit > Free Transform to resize, rotate, flip, or skew it 18 7 Fill the custom shape with a pattern Next we'll apply one of Photoshop' s pattern effects to make our shape more interesting Select the new shape in the layers palette, and then choose Layer > Change Layer Content > Pattern Click the pattern in the Pattern Fill dialog . icon next to the effect. Using Photoshop selection tools Having trouble deciding how to select part of your image? Adobe Photoshop gives you several tools. in the printer options dialog box, click the Print button. Using Photoshop shapes Adobe Photoshop makes it easy to add shapes to an image: you can draw