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 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 grayscale image 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. Midtones are 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: Brightness is defined by a pixel’s grayscale value: the higher the number, the brighter the pixel.) What is contrast? (Answer: Contrast is 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 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 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 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 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 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 Color Balance Vibrance 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