Transforming objects in two dimensions

Transforming objects in two dimensions

You can scale rotate skew distort and apply perspective to entire layers selected parts of layers masks paths shapes selection borders and channels.

Note: Pixels are added or deleted during transformations. To calculate the color values of these pixels Photoshop and ImageReady use the interpolation method selected in the General section of the Preferences dialog box. This option directly affects the speed and quality of the transformation Bicubic interpolation the default is slowest but yields the best results (See "Choosing an interpolation method" on section 66

Specifying what to transform

You can apply transformations to a selection an entire layer multiple layers or a layer mask In Photoshop you can also apply transformations to a path a vector shape a vector mask a selection border or an alpha channel.

Note: You cannot apply transformations to16 bit-per-channel images. You can however, apply full canvas transformations to 16-bit images using the options in the Image menu.

(See "Rotating and flipping entire images" on section 177

To specify what to transform:

Do one of the following:

To transform an entire layer make the layer active and make sure nothing is selected. Important: You cannot transform the background layer However you can convert a background layer to a regular layer (See Adding layers and layer sets" on section 286

To transform part of a layer select the layer and then select part of the image on that layer.

To transform multiple layers link the layers together in the Layers palette (See "Linking layers on section 289

To transform a layer mask or a vector mask unlink the mask and select the mask thumbnail in the Layers palette (See "Masking layers on section 314

(Photoshop) To transform a path or vector shape use the path selection tool to select the entire path or the direct selection tool to select part of the path If you select one

or more points on a path only those path segments connected to the points are trans- formed (See "Selecting paths (Photoshop) on section 211

(Photoshop) To transform a selection border make or load a selection. Then choose

Select > Transform Selection.

(Photoshop) To transform an alpha channel select the channel in the Channels palette.

(See "Storing masks in alpha channels on section 280

Setting the reference point

All transformations are performed around a fixed point called the reference point By default this point is at the center of the item you are transforming However you can change the reference point or move the center point to a different location.

To set the reference point for a transformation:

Select a transformation command as described in the following topics A bounding box appears in the image.

In the options bar click a square on the reference point locator . Each square repre- sents a point on the bounding box For example to set the reference point to the top left corner of the bounding box click the top left square on the reference point locator.

To move the center point for the transformation:

Select a transformation command as described in the following topics A bounding box appears in the image.

Drag the center point. The center point can be outside the item you want to transform.

Applying transformations

The commands under the Transform submenu let you apply the following transforma- tions to an item:

Scaling enlarges or reduces an item relative to its reference point. You can scale horizontally vertically or both horizontally and vertically.

Rotating turns an item around a reference point By default this point is at the center of the object however you can move it to another location.

Skewing lets you slant an item vertically and horizontally.

Distorting lets you stretch an item in all directions.

Applying perspective lets you apply one-point perspective to an item.

In Photoshop you can perform several commands in succession before applying the cumulative transformation For example you can choose Scale drag a handle to scale and then choose Distort drag a handle to distort and press Enter or Return to apply both transformations In ImageReady you can perform multiple types of transformations at the same time using the Transform > Numeric command.

To scale rotate skew distort or apply perspective:

Select what you want to transform (See "Specifying what to transform on section 181

Choose Edit > Transform > Scale Rotate Skew Distort or Perspective.

Note: (Photoshop) If you are transforming a shape or entire path the Transform menu becomes the Transform Path menu If you are transforming multiple path segments

(but not the entire path) the Transform menu becomes the Transform Points menu.

In the options bar click a square on the reference point locator . (See "Setting the reference point on section 182

Do one or more of the following:

If you chose Scale drag a handle on the bounding box Press Shift as you drag a corner handle to scale proportionately. When positioned over a handle the pointer becomes a double arrow.

If you chose Rotate move the pointer outside of the bounding border (it becomes a curved two-sided arrow) and then drag Press Shift to constrain the rotation to 15 increments.

If you chose Skew drag a side handle to slant the bounding box.

If you chose Distort drag a corner handle to stretch the bounding box.

If you chose Perspective drag a corner handle to apply perspective to the bounding box.

For all types of transformations enter a value in the options bar For example to rotate an item specify degrees in the rotation text box.

If desired switch to a different type of transformation by selecting a command from the

Edit > Transform submenu.

When transforming a bitmap image (versus a shape or path) it becomes slightly less sharp each time you commit a transformation therefore performing multiple

commands before applying the cumulative transformation is preferable to applying each transformation separately.

When you re satisfied with the results 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 transformation marquee.

To cancel the transformation press Esc or click the Cancel button in the options bar.

To flip or rotate precisely:

Select what you want to transform (See "Specifying what to transform on section 181

Choose Edit > Transform and choose one of the following commands from the submenu:

Rotate 180 to rotate by a half-turn.

Rotate 90 CW to rotate clockwise by a quarter-turn.

Rotate 90 CCW to rotate counterclockwise by a quarter-turn.

Flip Horizontal to flip horizontally along the vertical axis.

Flip Vertical to flip vertically along the horizontal axis.

Note: (Photoshop) If you are transforming a shape or entire path the Transform command becomes the Transform Path command If you are transforming multiple path segments (but not the entire path) the Transform command becomes the Transform Points command.

To repeat a transformation:

Choose Edit > Transform > Again Edit > Transform Path > Again or Edit > Transform

Points > Again.

To duplicate an item when transforming it:

Hold down Alt ( Windows) or Option (Mac OS) when selecting the Transform command.

To apply multiple types of transformations at the same time (ImageReady):

Select what you want to transform (See "Specifying what to transform on section 181

Choose Edit > Transform > Numeric.

Do one or more of the following and click OK:

Select Position and enter values for the new location in the X (horizontal position) and Y

(vertical position) text boxes Select Relative to specify the new position in relation to the current position.

Select Scale Enter the dimensions in the W and H text boxes or enter a scaling percentage in the Scale text box Select Constrain Proportions to maintain the aspect ratio.

Select Skew and enter degrees in the H (horizontal skew) and V (vertical skew) text boxes.

Select Rotate Enter degrees of rotation in the Angle text box or drag the in the circle to the right of the text box.

Using the Free Transform command

The Free Transform command lets you apply transformations (rotate scale skew distort, and perspective) in one continuous operation Instead of choosing different commands, you simply hold down a key on your keyboard to switch between transformation types. To freely transform:

Select what you want to transform (See "Specifying what to transform on section 181

Do one of the following:

Choose Edit > Free Transform.

Note: (Photoshop) If you are transforming a shape or entire path the Transform command becomes the Transform Path command If you are transforming multiple path segments (but not the entire path) the Transform command becomes the Transform Points command.

If you are transforming a selection pixel-based layer or selection border choose the move tool . Then select Show Bounding Box in the options bar.

If you are transforming a vector shape or path select the path selection tool . Then select Show Bounding Box in the options bar.

Do one or more of the following:

To scale by dragging drag a handle Press Shift as you drag a corner handle to scale proportionately.

To scale numerically enter percentages in the W and H text boxes in the options bar. In Photoshop click the link button to maintain the aspect ratio.

To rotate by dragging move the pointer outside of the bounding border (it becomes a curved two-sided arrow ) and then drag Press Shift to constrain the rotation to 15 increments.

To rotate numerically enter degrees in the rotation text box in the options bar.

To distort relative to the center point of the bounding border press Alt ( Windows) or

Option (Mac OS) and drag a handle .

To distort freely press Ctrl ( Windows) or Command (Mac OS) and drag a handle.

To skew press Ctrl+Shift ( Windows) or Command+Shift (Mac OS) and drag a side handle. When positioned over a side handle the pointer becomes a white arrowhead with a small double arrow .

To skew numerically enter degrees in the H (horizontal skew) and V (vertical skew) text boxes in the options bar.

To apply perspective press Ctrl+Alt+Shift ( Windows) or Command+Option+Shift

(Mac OS) and drag a corner handle. When positioned over a corner handle the pointer becomes a gray arrowhead .

To change the reference point click a square on the reference point locator in the options bar (See "Setting the reference point on section 182

To move an item enter values for the new location of the reference in the X (horizontal position) and Y (vertical position) text boxes in the options bar In Photoshop click the Relative Positioning button to specify the new position in relation to the current position.

To undo the last handle adjustment choose Edit > Undo.

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 transformation marquee.

To cancel the transformation press Esc or click the Cancel button in the options bar. When transforming a bitmap image (versus a shape or path) it becomes slightly less sharp each time you commit a transformation therefore performing multiple

commands before applying the cumulative transformation is preferable to applying each transformation separately.