Writing Interactive DE materials

Done by:Abir ALmuqrashi(89407)

Fatema ALHajri(89407)

The lesson is designed to be done in Adobe Photoshop

Section 1: Strategy for retouching

Student can retouch photographic images in ways once available only to highly trained specialists. He can

correct problems in color quality and tonal range created during the original photography or during image

scanning. He can also correct problems in composition and sharpen the overall focus of the image.

Photoshop provides a comprehensive set of color-correction tools for adjusting the color and tone of

individual images.

Most retouching follows these eight general steps:

1. Duplicating the original image or scan. (Always work in a copy of the image file, so that you

can recover the original later if necessary.)

2. Checking the scan quality and making sure that the resolution is appropriate for the way you

will use the image.

3. Cropping the image to final size and orientation.

4. Repairing flaws in scans of damaged photographs (such as rips, dust, or stains)

5. Adjusting the overall contrast or tonal range of the image.

6. Removing any color casts.

7. Adjusting the color and tone in specific parts of the image to bring out highlights, midtowns,

shadows, and desiderated colors.

8. Sharpening the overall focus of the image.

Section2: Straightening and cropping an image

You’ll use the Crop tool to trim and scale the photograph for this lesson so that it fits the

space designed for it. You can use either the Crop tool or the Crop command to crop an

image. Both methods permanently delete all the pixels outside the crop selection area.

1. In the toolbox, select the Crop tool ( ). Then, on the tool options bar (at the top of the work

area), enter the dimensions (in inches) of the finished image: For Width type2 in, and for Height

type 3 in.

2. Open the image (C*-O). Choose the Marquee (crop) tool (C).

3. Drag the Marquee over the portion of the image that you want to keep.

4. Press Enter/Return or Double-click inside the marquee.

Section3: Adjusting the tonal range

The tonal range of an image represents the amount of contrast, or detail, in the image and is determined

by the image’s distribution of pixels, ranging from the darkest pixels (black) to the lightest pixels (white).

Student will now correct the photograph’s contrast using the Levels command.

1- Use the Adjust/Enhance > Brightness/Contrast > Levels menu to open the Levels dialog box. You can

simply click the Auto button to automatically adjust the tonal range, or perform the following steps

manually. To adjust it manually, you can adjust the Red, Green, and Blue channels in one

adjustment or individually. The remaining steps are examples of how to adjust the channels

individually.

Select the red channel and you will see in the histogram that most of the input comes from the

shadow (dark) end of the scale. In order to make the most of available color information, you can

move the black (left) and white (right) triangles in the Input box from the original 0-255 range to the

0-168 range as shown in Figure 10.02.2.

Apply the same method to the green and blue channels

Section4: Removing a color cast

Some images contain color casts (imbalanced colors), which may occur during scanning or which may have

existed in the original image. This photograph of the window has a blue cast. Student will use the Auto

Color feature to correct this.

1. Open up a color image in Photoshop that has a color cast or tint.

1. Click the Image menu and select the adjustments option then the levels option.

2. This will open the Levels dialog box. If this box is coving much of your image try to move it

off to one side if you have room. Now look at the bottom right hand corner of the levels

dialog box and you should see 3 buttons in a row with a picture of an eyedropper. One

black, one grey, and one white. Double click the white one.

A new box should open up. Again if it is covering much of your image try to move it to one

side. Now Look at your image and find a spot on it that should be white but isn’t due to the

color cast. Good places to look for white in images are peoples socks, white t-shirts, pieces

of paper, but really any spot that should be white will work. Now the ideal spot shouldn’t be

100% pure white, but just a tiny bit darker but still fairly white. Now click that spot with your

mouse.

Now don’t touch your mouse! You need to leave the mouse in the exact spot that you

clicked for this trick to work.

Now look for three little boxes in a group in the color picker dialog box that have the letters

R G and B to the left of them

Section5: Replacing colors in an image

With the Replace Color command, student can create temporary masks based on specific colors and then

replace these colors. (A mask isolates an area of an image, so that changes affect just the selected area and

not the rest of the image.) The Replace Color dialog box contains options for adjusting the hue, saturation,

and lightness components of the selection: Hue is color, saturation is the purity of the color, and lightness

is how much white or black is in the image.

1. Select the Rectangular Marquee tool (< ), and draw a selection border around the blue wall at the

top of the image. Don’t worry about making a perfect selection, but be sure to include all of the

blue wall.

2. Choose Image > Adjustments > Replace Color to open the Replace Color dialog box.

By default, the Selection area of the Replace Color dialog box displays a black rectangle,

representing the current selection.

A. Single-color Eyedropper tool

B. Eyedropper Plus tool

C. Eyedropper Minus tool

3. Using the first (single-color) Eyedropper tool ( ) in the Replace Color dialog box, click anywhere in

the blue-wall area of the image window to select all of the area with that color.

4. In the Replace Color dialog box, select the Eyedropper Plus tool ( ), and use it to select other

areas of the blue wall until the entire wall shape is highlighted in white in the dialog box.

5. Adjust the tolerance level by scrubbing, dragging the Fuzziness slider, or typing 80.

Fuzziness controls the degree to which related colors are included in the mask.

6. If there are any white areas of the mask display in the dialog box that are not part of the wall and

therefore should not be included, fix those now: Select the Eyedropper Minus tool ( ) and click

those areas in either the image window or the Replace Color dialog box to remove most of the

white. (It’s OK if a few pixels in the shadowed window inset remain in the selection.)

7. In the Replacement area of the Replace Color dialog box, drag the Hue slider to –40, the Saturation

slider to –45, and leave the Lightness slider at 0.

As you change the values, the color of the wall changes in hue, saturation, and lightness, so that the

wall is now a slaty green color.