Improving Image Quality Using Adobe PhotoShop
I. Open your first image in Adobe PhotoShop.
PhotoShop has several tools and techniques that are designed to improve image quality of photographic images. This project will lead you through the application of several of those tools and techniques.
II. It is good practice to use PhotoShop layers in this unit so that you can see the effect of changes that you make.
1. Go to the top of the PhotoShop workspace and find the “Layers” column.
2. Select “Duplicate Layer.” (You could choose to create a specific kind of layer, but the command “duplicate layer” is simple and works well for these projects.)
Using PhotoShop “Curves”
A. Move your cursor to the top of your screen where you see the word “Image” and click the left mouse button one time to open that column of menu choices.
B. Move your cursor down the list to the word “Adjustments” and click the left mouse button one time.
C. Move your cursor over toward the right – to the word “Curves” and click the left mouse button one time.
1. In the upper part of the dialog box a line will say, “Preset – default” don’t make any changes there.
2. Under the preset line there will be a channel line. The normal setting there is RGB, but you can change the “Channel” and see how that affects the color in your picture.
3. Under the channel line there is an Output graph with a diagonal line over a “histograph” that shows the distribution of light & dark tones in your picture.
4. Under the graph there are three eyedroppers – one for blacks, one for grays, and one for whites. Click on an eyedropper then click on the picture to see what happens. (To undo – hold the Alt key down and, next to the graph, click on “reset.”)
5. Click any part of the line, hold your mouse down and drag the line up, down or sideways, and watch what happens to your image. (The tonal range in the picture represented by that point on the graph will change.
To undo – hold the Alt key down and, next to the graph, click on “reset.”)
6. You can also use curves to make adjustments to the color cast of your image. At the top of the curves box, under presets, you will see a box to select a color channel. Choose a color, then click on a part of the line, hold your mouse down and drag the line up, down or sideways, and watch what happens to your image. (To undo – hold the Alt key down and, next to the graph, click on “reset.”)
Using PhotoShop “Shadows/Highlights”
A. Move your cursor to the top of your screen where you see the word “Image” and click the left mouse button one time to open that column of menu choices.
B. Move your cursor down the list to the word “Adjustments” and click the left mouse button one time.
C. Move your cursor down the list to – to the “Shadows/Highlights” and click the left mouse button one time.
D. A new dialog box will appear – look at the bottom and make sure that there is a check mark in the box next to “Show more options.”
· Under the shadow and highlight sections there are are lines with arrows under them
· -Amount: determines the degree to which the effect is applied to the image (Ranges from 0 – 100 %) Start with small changes and adjust the slider to the left or right to make the image appear the way you think it looks best.
· - Tonal Width: Controls the range of tones in the shadows or highlights that are modified.
· - Radius: Controls the number of pixels surrounding the edge pixels that are affected by the sharpening. Ranges from 0 – 2500 pixels. To start with, try setting the radius at a fairly high number – a little more than half-way across the range.
· You can also adjust the amount of color correction and contrast that happen along with the lightening or darkening process. (Usually you don’t need to adjust these.)
· Move the arrows until your picture looks the way you want it to look.
Using PhotoShop “Levels”
A. Move your cursor to the top of your screen where you see the word “Image” and click the left mouse button one time to open that column of menu choices.
B. Move your cursor down the list to the word “Adjust” or “Adjustments” and click the left mouse button one time.
C. Move your cursor over toward the right – to the word “Levels” and click the left mouse button one time.
D. A Levels “dialog box” will open, with “channel,” “input levels” and “output levels”
E. Under the “input levels” section there is a graphic chart called a histogram with three arrows under it and, just below that, three boxes with numbers in them.
· The left arrow controls / changes the black tones.
· The middle arrow controls / changes the gray tones.
· The right arrow controls / changes the white tones.
· Moving any arrow to the left makes that tone lighter
· Moving any arrow to the right makes that tone darker.
· Move the arrows until your picture looks the way you want it to look.
F. There is also an “output levels” section where you will see a set of two boxes and a graphic chart with two arrows which can also be adjusted.
· Adjust these arrows as needed.
G. When you have finished making your adjustments, click the left mouse button one time on the word “OK”
H. Before you go to the next step, go to the layers column and create a new duplicate layer by repeating the instructions given in step II above.
Scratches / Spots - use the clone tool or patch tool (located in the vertical tool bar) to copy the desired tone from a target area to the scratched or spotted area.
A. …
a. Click on clone tool.
b. Bring cursor to hover over area you want to copy from.
c. Press Alt key and click mouse button down (circle changes to a “target”).
d. Release alt key and release mouse button.
e. Move cursor to area you want to repair.
f. Click mouse button down and drag brush circle over that area.
B. NOTE: you may need to repeat A-b through A-d several times during the process of repair because the “target” area moves whenever you move the brush.
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Adjusting Sharpness Using PhotoShop (Note- you cannot make a really blurry picture really sharp, but you can improve the appearance of sharpness a little.)
a) Move your cursor to the top of your screen where you see the word “Filters” and click the left mouse button one time to open that column of menu choices.
b) Move your cursor down the list to the word “Sharpen” and click the left mouse button one time.
c) Move your cursor over toward the right – to either “Unsharp Mask” or “Smart Sharpen” and click the left mouse button one time.
d) A new “dialog box” will open, with three rows of sliding arrows
· The first row / sliding arrow controls the “Amount”
· The second row / sliding arrow controls the “Radius”
· The third row / sliding arrow controls the “Threshold”
· Move the arrows until your picture looks sharper but not too ‘blocky’ or ‘pixelated’ looking.
e) Before you go to the next step, go to the layers column and create a new duplicate layer by repeating the instructions given in step II above.
“NOISE” (“Grainy” appearance of photos)
If your picture looks very “grainy” either on your computer screen or in your printed image, you can reduce that problem a little bit as follows:
a) Move your cursor to the top of your screen where you see the word “Filters” and click the left mouse button one time to open that column of menu choices.
b) Move your cursor down the list to the word “Noise” and click the left mouse button one time.
c) Move your cursor over toward the right – to the word “Despeckle” and click the left mouse button one time.
III. Saving files for making prints
(Note: While you are working on this project be sure to save your work as Photoshop (.psd) type files so that you will be able to save all of the layers you need to create. When you are finished, you will “flatten the layers and re-save the file as a jpg or tif file, depending on how much available memory space you have.)
A. When you have made all the desired improvements to your image quality, go to “Layer,” then to “Flatten Image.”
B. Go to “File” then to “Save As.”
C. Save your file under a new name. If you have enough storage space, save your file as a tif file; otherwise, save it as a jpeg file.
D. Repeat this process for each of your images.
E. Now you are ready to make prints if desired. If the printed image looks very different from the image on your computer screen you may need to make some adjustments to the printer settings, to your computer monitor brightness / contrast / color settings, or within the PhotoShop program you may need to go to “View, then to “Proof Set-up” and choose a different printer profile. Your manuals will be your best resources for making any of these changes.