Transforming and Retouching

Transforming and Retouching

Changing the size of the work canvas

The Canvas Size command lets you add or remove work space around an existing image. You can crop an image by decreasing the canvas area. Added canvas appears in the same color or transparency as the background.

To use the Canvas Size command:

1Choose Image > Canvas Size.

2(Photoshop) Choose the units of measurement you want.

3The Columns option measures width in terms of the columns specified in the Rulers & Units preferences. For more information, see “Using columns (Photoshop)” on page 44.

4Do one of the following:

•Enter the dimensions you want the canvas to be in the Width and Height boxes.

•Select Relative, and enter the amount by which you want to increase or decrease the size of the canvas. (Enter a negative number to decrease the size of the canvas.)

5For Anchor, click a square to indicate where to position the existing image on the new canvas.

6Click OK.

Original canvas, and canvas added to top of image

Rotating and flipping entire images

The Rotate Canvas commands let you rotate or flip an entire image.The commands do not work on individual layers or parts of layers, paths, or selection borders.

To rotate or flip an entire image:

Choose Image > Rotate Canvas, and choose one of the following commands from the submenu:

•180° to rotate the image by a half-turn.

•90° CW to rotate the image clockwise by a quarter-turn.

•90° CCW to rotate the image counterclockwise by a quarter-turn.

•Arbitrary to rotate the image by the angle you specify. If you choose this option, enter an angle between –359.99 and 359.99 in the angle text box, and then select CW or CCW to rotate clockwise or counterclockwise. Click OK.

•Flip Canvas Horizontal (Photoshop) or Flip Horizontal (ImageReady) to flip the image horizontally, along the vertical axis.

•Flip Canvas Vertical (Photoshop) or Flip Vertical (ImageReady) to flip the image vertically, along the horizontal axis.

Cropping images

Cropping is the process of removing portions of an image to create focus or strengthen the composition. You can crop an image using the crop tool and the Crop command. You can also trim pixels using the Trim command.

The crop tool provides the most options for cropping images.

To crop an image using the crop tool:

1Select the crop tool .

2Set the mode of the crop tool:

•(Photoshop) To crop the image without resampling (default), make sure that all the text boxes in the options bar are empty. You can click the Clear button to quickly clear all text boxes.

•(Photoshop) To resample the image during cropping, enter a height, width, and/or resolution in the options bar.

•(ImageReady) To crop the image without resampling, make sure that Fixed Size is deselected in the options bar.

•(ImageReady) To resample the image during cropping, select Fixed Size, and enter a height and width in the options bar.

•To resample an image based on the dimensions and resolution of another image, open the other image, select the crop tool, and click Front Image in the options bar. (In ImageReady, you must select the Fixed Size option to access the Front Image button.) Then make the image you want to crop active.

Resampling during cropping combines the function of the Image > Image Size command with that of the crop tool. (See “About resampling” on page 66.)

3 Define the cropping marquee by dragging over the part of the image you want to keep. The marquee doesn’t have to be precise—you can adjust it later.

4 Do the following in the options bar:

•Specify whether you want to hide or delete the cropped area. Select Hide to preserve the cropped area in the image file.You can make the hidden area visible by moving the image with the move tool. Select Delete to discard the cropped area.

Note: In Photoshop, the Hide option is not available for images that contain only a background layer. If you want to crop a background by hiding, convert the background to a regular layer first. (See “About the background layer” on page 285.) In ImageReady, cropping a background by hiding automatically converts the background to a regular layer.

•Specify whether you want to use a cropping shield to shade the area of the image that will be deleted or hidden. When Shield is selected, you can specify a color and opacity for the cropping shield. When Shield is deselected, the area outside the cropping marquee is revealed.

5 If necessary, adjust the cropping marquee:

•To move the marquee to another position, place the pointer inside the bounding box and drag.

•To scale the marquee, drag a handle. To constrain the proportions, hold down Shift as you drag a corner handle.

•To rotate the marquee, position the pointer outside the bounding box (the pointer turns into a curved arrow), and drag. To move the center point around which the marquee rotates, drag the circle at the center of the bounding box.

Note: In Photoshop, you can’t rotate the marquee for an image in Bitmap mode.

6 Do one of the following:

•Press Enter (Windows) or Return (Mac OS); click the Commit button in the options bar; or double-click inside the cropping marquee.

•To cancel the cropping operation, press Esc or click the Cancel button in the options bar.

To crop an image using the Crop command:

1Select the part of the image you want to keep. (See “Using the marquee tools” on page 158.)

2Choose Image > Crop.

To crop an image using the Trim command:

1Choose Image > Trim.

2In the Trim dialog box, select an option:

•Transparent Pixels to trim away transparency at the edges of the image, leaving the smallest image containing non-transparent pixels.

•Top Left Pixel Color to remove an area the color of the upper left pixel from the image.

•Bottom Right Pixel Color to remove an area the color of the lower right pixel from the image.

3 Select one or more areas of the image to trim away: Top, Bottom, Left, or Right.

Transforming perspective while cropping (Photoshop)

The crop tool in Photoshop has an additional option that allows you to transform the perspective in an image. This is very useful when working with images that contain keystone distortion. Keystone distortion occurs when an object is photographed from an angle rather than from a straight-on view. For example, if you take a picture of a a tall building from ground level, the edges of the building appear closer at the top than they do at the bottom.

Note: You cannot transform the perspective of 16-bit-per-channel images.

Steps to transform perspective:

A. Draw initial cropping marquee B. Adjust cropping marquee to match the object’s edges C. Extend the cropping bounds D. Final image

To transform the perspective in an image:

1Select the crop tool and set the crop mode. (See “Cropping images” on page 178.)

2Drag the cropping marquee around an object that was rectangular in the original scene (although it doesn’t appear rectangular in the image).You’ll use the edges of this object to define the perspective in the image. The marquee doesn’t have to be precise—you’ll adjust it later.

Important: You must select an object that was rectangular in the original scene or Photoshop will not be able to transform the perspective in the image.

3Select Perspective in the options bar, and set the other options as desired. (See “Cropping images” on page 178.)

4Move the corner handles of the cropping marquee to match the object’s edges. This defines the perspective in the image, so it is important to precisely match the object’s edges.