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Adobe Photoshop CS5 – Illustrated Unit E: Improving Images with Adjustment Layers. Objectives. Understand grayscale Investigate a grayscale image Use the Brightness/Contrast adjustment Adjust black and white points with levels. Objectives. Adjust the midpoint with levels
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Adobe Photoshop CS5 – IllustratedUnit E: Improving Images with Adjustment Layers
Objectives • Understand grayscale • Investigate a grayscale image • Use the Brightness/Contrast adjustment • Adjust black and white points with levels Adobe Photoshop CS5 - Illustrated
Objectives • Adjust the midpoint with levels • Investigate an RGB image • Use the Color Balance adjustment • Use the Vibrance adjustment Adobe Photoshop CS5 - Illustrated
Improving Images with Adjustment Layers • Images can come from anywhere • Photoshop’s practical operations • Improve image characteristics • Color, contrast, overall effect • Adjustment layer • Allows for adjustments applied to image • Does not directly affect the artwork • Called “non-destructive” • Exists as a layer on the Layers panel Adobe Photoshop CS5 - Illustrated
Understanding Grayscale • Grayscale digital image • Each pixel: one of 256 shades of gray • 256 shades of gray • Creates continuous tone image illusion • Grayscale range: 0-255 • Pixels grayscale value of zero: black • Pixels grayscale value of 255: white • Any number in between: light to dark gray • 128: middle point in the grayscale range Adobe Photoshop CS5 - Illustrated
Understanding Grayscale • Sampling pixels • Identifying pixel information in the info panels • Info panel displays the Grayscale readouts sample pixels in ink percentages • Readout provides information for the printed image resolution Adobe Photoshop CS5 - Illustrated
Understanding Grayscale Info panel settings Sampling the lightest pixels in the Image Adobe Photoshop CS5 - Illustrated
CLASSROOM ACTIVITIES • True/False. A grayscaleimage refers to a digital image in which each pixel can be one—and only one—of 256 shades of gray. (Answer: True) • 2. Quick Quiz: True/False. Pixels with a grayscale value of 0 are white. (Answer: False) Adobe Photoshop CS5 - Illustrated
Investigating a Grayscale Image • Analyzing image appearance • Identify highlights, shadows, midtones • Highlights • Lightest image areas • Pixels values in upper third of grayscale range • Shadows • Darkest areas • Pixels in low third of the grayscale range Adobe Photoshop CS5 - Illustrated
Investigating a Grayscale Image • Midtones • Fall into middle grayscale range • Individual digital image pixels • Illusion of continuous tone • Smooth transition from shadows to midtones to highlights • Creation of illusions • Requires sufficient number of grays available per pixel Adobe Photoshop CS5 - Illustrated
Investigating a Grayscale Image Shadows, midtones, and highlights identified on the gradient Image 3 shades of gray available per pixel Image with 16 shades of gray available per pixel Adobe Photoshop CS5 - Illustrated
CLASSROOM ACTIVITIES • True/False. Midtonesare the darkest areas represented by pixels in the low third of the grayscale range. • (Answer: False) • Why the number values on the right of the info panel can only be 0, 148, or 255. Adobe Photoshop CS5 - Illustrated
Using the Brightness/Contrast Adjustment • Adjustments • Operations affecting image appearance • Manipulating brightness and contrast • Can be made directly to pixels on a layer • Cannot go back and readjust at a later time • Creation of adjustments layers • Adjustments existing as layers on the Layers panel • Affect image • Can be manipulated at a later time Adobe Photoshop CS5 - Illustrated
Using the Brightness/Contrast Adjustment • Adjustment layer • Can be hidden, re-shown, deleted at any time • Brightness/Contrast adjustment • Brightness: defined by grayscale value • Higher the number, the brighter the pixel • Contrast: represented by the relationship between the highlights and shadows • Good when highlights and shadows distinctly different in tonal range; not “flat” Adobe Photoshop CS5 - Illustrated
Using the Brightness/Contrast Adjustment • Key to making adjustments • Walk the fine line between going far enough and going to far with the adjustment • Designers • Push adjustment to the extreme • To see what the adjustment looks like • Can easily see what is not wanted • Can make it easier to make adjustments Adobe Photoshop CS5 - Illustrated
Using the Brightness/Contrast Adjustment Increasing the brightness Before and after the adjustment Adobe Photoshop CS5 - Illustrated
CLASSROOM ACTIVITIES • What is brightness? (Answer: Brightnessis defined by a pixel’s grayscale value: the higher the number, the brighter the pixel.) • What is contrast? (Answer: Contrastis represented by the relationship between the highlights and shadows.) Adobe Photoshop CS5 - Illustrated
Adjusting Black and White Points with Levels • Start and end of the image tonal range • Black point • Represents darkest image pixel • White point • Represents brightest image pixel Adobe Photoshop CS5 - Illustrated
Adjusting Black and White Points with Levels • Black and white points • Have substantial effect on contrast • Cameras set to capture image without making too many shadows or highlights that are too white • Results provide a smooth tonal range • Image still lacks contrast Adobe Photoshop CS5 - Illustrated
Adjusting Black and White Points with Levels • The Levels adjustment • Fixes shadows: not dark enough • Fixes highlights: not quite white enough • Histogram component • Adjusts image by manipulating sliders at the bottom Levels adjustment options on the Adjustments panel Adobe Photoshop CS5 - Illustrated
Adjusting Black and White Points with Levels Adjustments panel with Levels adjustment layer settings Adjusting the black and white points Adobe Photoshop CS5 - Illustrated
CLASSROOM ACTIVITIES • True/False. Every image has a black point. (Answer: True) • Which point represents the brightest pixel in the image? (Answer: the white point) Adobe Photoshop CS5 - Illustrated
Adjusting the Midpoint with Levels • Midpoint • Defines areas of image falling into the available grayscale range middle • Moving the midpoint lightens or darkens the image • Start at the outside and work inwards • Set black and white points: the extremes • Verify satisfactory contrast between highlight and shadow range • Midpoint can be adjusted Adobe Photoshop CS5 - Illustrated
Adjusting the Midpoint with Levels • Adjustment layer creation • Created automatically with a layer mask • Like the Levels adjustment • Layer mask • Applies adjustment selectively in different strengths to different areas of artwork Adobe Photoshop CS5 - Illustrated
Adjusting the Midpoint with Levels Brightening the midtones Masking areas of the image from the adjustment Adobe Photoshop CS5 - Illustrated
CLASSROOM ACTIVITIES • True/False. You begin with the midpoint. (Answer: False) • True/False. You can rename a layer. (Answer: True) Adobe Photoshop CS5 - Illustrated
Investigating an RGB Image • Monitors display color as light • Red, green, blue: additive primary colors of light • Combine to produce all other colors in the spectrum • Mixing varying strengths produce yellows, purples, limes, etc. • RGB: like grayscale • Various shades available per pixel • 256 shades of red, green, and blue Adobe Photoshop CS5 - Illustrated
Investigating an RGB Image • Color printing • Use cyan, magenta and yellow inks plus black for detail (CMYK) • Different than primary colors for viewing with a monitor: red, green and blue • Cyan, magenta, and yellow • Each created by removing on the additive RGB primary colors • Photoshop’s color adjustment dialog boxes use RGB and CMY as basis Adobe Photoshop CS5 - Illustrated
Investigating an RGB Image Viewing the Red channel only Viewing the image with no red component Viewing the image with no blue component Adobe Photoshop CS5 - Illustrated
CLASSROOM ACTIVITIES • Which color is “minus blue”? (Answer: yellow) • What the additive primary colors of light are. Have them discuss the colors of the spectrum in reference to the additive primary colors. Adobe Photoshop CS5 - Illustrated
Using the Color Balance Adjustment • Color Balance • Adjustment controlling balance of red, green and blue in an image • Digital camera images often too red • Fixed using the Color Balance adjustment Adobe Photoshop CS5 - Illustrated
Using the Color Balance Adjustment • Pixel’s red component number • Substantially greater than green and blue number will have a red hue • If numbers for red, green and blue colors are close in value: • Pixel becomes neutral in color • If numbers are the same: • Pixel will have no color • Can only be a neutral gray Adobe Photoshop CS5 - Illustrated
Using the Color Balance Adjustment Color Balance adjustment Before and after the adjustment Adobe Photoshop CS5 - Illustrated
CLASSROOM ACTIVITIES • What three colors in an image can you control? • (Answer: red, green, and blue) • True/False. Whites in eyes are a great place to sample for midtones and highlights. • (Answer: True) Adobe Photoshop CS5 - Illustrated
Using the Vibrance Adjustment • Vibrance adjustment • Useful for quickly making colors in an image more vibrant • Vibrance • Refers to intensity of a color • Measure of a pixel’s vibrance • Called saturation • High saturation produces vibrant color • Reduced saturation produces dull, more neutral color • Pixel with no saturation: neutral gray Adobe Photoshop CS5 - Illustrated
Using the Vibrance Adjustment • Vibrance Adjustment settings • Saturation • Increases or decreases saturation value of all pixels selected • Vibrancy • Increases saturation of pixels needing it • Does not affect pixels already saturated Adobe Photoshop CS5 - Illustrated
Using the Vibrance Adjustment Over saturating the image Before and after the adjustment Adobe Photoshop CS5 - Illustrated
CLASSROOM ACTIVITIES • What refers to the measure of a pixel’s vibrance? • (Answer: saturation) • True/False. The last state listed in the History panel represents the first change you made to the file. • (Answer: False) Adobe Photoshop CS5 - Illustrated
Summary • Photoshop offers practical operations • Improve characteristics of images • Color, contrast, overall effect • Analyzing image appearance first step • Image highlights, shadows, midtones • Digital image • Illusion of continuous tone • Black point: darkest pixel in the image • White point: brightest pixel in image Adobe Photoshop CS5 - Illustrated
Summary • Levels adjustment • Fixes shadows not dark enough • Fixes highlights not quite white enough • Color Balance • Adjustment controlling image balance of red, green and blue • Vibrance adjustment • Provides a setting for saturation and vibrancy Adobe Photoshop CS5 - Illustrated