Moving and resizing image files

Raster images that have been attached to a design may be moved, rotated and/or resized. You can do this with the Modify tool. Another option is to use the Warp tool, which is useful for matching a raster image to design file elements.

Georeferencing and positioning information is kept in the raster file header for georeferenced file formats. For non-georeferenced image formats, it is either written to a location info sister file or simply kept in the image's design file attachment. Warping, mirroring and resizing parameters are also kept in the design file's raster attachment. If the image is detached, these settings are deleted. In order to apply warping, mirroring and resizing settings, a new image must be saved using the Save As menu with the Option > Resample toggle set to on.

Using the Modify tool

With this tool you can modify a raster image's origin, size, rotation and/or affinity. Only one raster file at a time can be modified either via the tool settings window or interactively.

Using the fields in the tool settings window, you can define the Origin coordinate values, the angle of rotation or affinity, as well as change the scale. You can change the scale by defining the size of each pixel, in working units, in the X and/or Y direction. Alternatively, you can set the scaling to be by Scale Factor, which lets you define the scale and the DPI (dots per inch).

When working interactively, scaling and rotation modifications are performed relative to the image anchor point, which is set at the:

Image origin — when you select the image from the Raster Manager dialog box list.
Identification point — when you select the image with a data point.

You can make interactive modifications to scale, rotation or affinity via handles and arrow symbols, located at the midpoint of each edge, as well as at each vertex of the unclipped image. That is, if you have a raster image that has been cropped, a rectangle graphic defining the original attachment limits displays. Handles appear relative to this rectangular graphic. Additionally, you can place a data point on the image, away from the handles, to move the image interactively.


Raster image showing handles, arrows and origin point for interactive modification.

To scale a selected image interactively, about its origin

If there is more than one raster image attached, use the Raster Selection tool, or the Raster Manager dialog box to select the required raster image.

In the Raster Control tool box, select the Modify tool.
The selected raster image highlights, with handles and arrows showing the modification points, and circles showing the origin point.

Identify one of the handles and move the pointer to scale the raster image. Move the pointer away from the origin to increase the scale, or towards the origin to decrease the scale.

Enter a data point to complete the operation.


Moving a handle (left) and the scaled raster image (right)

Where you want to scale or rotate an image about a point other than the origin, you can move the image anchor point to the required location prior to scaling or rotating.

To set the image anchor point and rotate the image

Select the Modify tool.

With a data point, identify the image to modify.
This identification point becomes the image anchor point.

With a data point, identify the image anchor point.

Move the anchor point to its new position (you can snap to an existing element in the design).

Place a data point to complete the relocation.


Moving the image anchor point (left) and with it in its new position (right).

Place a data point on one of the curved arrows located at each vertex of the image.
As the pointer moves, the image now is rotated about the relocated image anchor.

Place a data point to complete the rotation.

Reset to deselect the image.

Using the same tool, Modify, you can move an image interactively.

To move an image interactively

Select the Modify tool.

With a data point, identify the image to move.
Anchors display on the selected image.

Place a data point on the image, away from the image anchor point.
The image now is attached to the screen pointer.

Move the image to its new location.

Place a data point to complete the move.

Reset to deselect the image.

Using the Warp tool

You can use the Warp tool to manipulate a raster image by moving, scaling, rotating, or skewing. Manipulation is accomplished by defining points on the image, and their corresponding points in the design file. Raster Manager uses this information to perform a best fit of the image to the design file points. Using this tool, for example, you can match a visible feature in an aerial mapping image to the corresponding feature in the design file.

To match an image feature to a design file element

Select the Warp tool.

If necessary, identify the raster image.

Set Method to the required setting, depending on the number of points available and the type of warping:
Align (Move, Scale) — requires two points.
Similitude (Move, Scale, Rotate) — minimum of two points.
Affine (Move, Scale, Rotate, Skew) — minimum of three points.

Identify a point in the raster image.

Identify the corresponding point in the design file.

Repeat steps 2 and 3 for additional points, as required.

Reset to warp the image.


Matching points in the image to points in the design (left) and the modified image (right).


With Similitude and Affine, the image can be rotated during warping.

If the image to warp has non-zero affinity, use the Similitude rather than the Affine method.