GC Image Users' Guide

Graphics

GC Image supports drawing and editing of graphical elements. Currently, points, polylines, rectangles, and polygons are supported. The Image Viewer palette contains a button to set the cursor mode to a graphics mode and there is a pull-down graphics mode selector. The selectable graphics cursor modes are:

Select Graphic: Select a graphic.
Draw Point: Draw a point.
Draw Polyline: Draw a polyline.
Draw Rectangle: Draw a rectangle.
Draw Polygon: Draw a polygon.

There is also a palette button to delete a selected graphic object and menu items for selecting all graphics objects and for importing and exporting files describing graphics objects. The Configure->Configure Settings interface allows setting of visibility options and default colors.

Draw Point

Create a point graphic by first setting the graphics mode to Draw Point. In this mode, depress the left mouse-button to set the location of the point. After the point graphic is drawn, the graphics cursor mode reverts to Select Graphic mode, with the point just created selected. Selected points are outlined graphically, as illustrated in Figure 1.

Figure 1: A selected point graphic.

Draw Polyline

Create a polyline graphic by first setting the graphics mode to Draw Polyline. In this mode, locate the cursor at the starting point of the polyline and click the left mouse-button. Then, similarly locate each successive point of the polyline and click the left mouse-button. At the ending point of the polyline, double-click the left mouse-button. After the polyline is drawn, the graphics cursor mode reverts to Select Graphic mode, with the polyline just drawn selected. The knots of selected polylines are highlighted graphically, as illustrated in Figure 2.

Figure 2: A selected point graphic.

Draw Rectangle

Create a rectangle graphic by first setting the graphics mode to Draw Rectangle. In this mode, depress the left mouse-button to set one corner of the rectangular sub-region, drag the cursor to the opposite corner of the rectangular sub-region, and release the mouse button. After the rectangle is drawn, the graphics cursor mode reverts to Select Graphic mode, with the rectangle just drawn selected. The corners of selected rectangles are highlighted graphically, as illustrated in Figure 3.

Figure 3: A selected rectangle graphic.

Draw Polygon

Create a polygon graphic by first setting the graphics mode to Draw Polygon. In this mode, click the left mouse-button to set one vertex of the polygon, repeatedly move the mouse to subsequent vertices and click the left mouse-button, and double-click the left mouse-button at the final vertex. After the polygon is drawn, the graphics cursor mode reverts to Select Graphic mode, with the polygon just drawn selected. The vertices of selected polygons are highlighted graphically, as illustrated in Figure 4.

Figure 4: A selected polygon graphic.

The visibility of graphics can be configured from Configure->Configure Settings on the Image Viewer menu bar. Visibility can be set to all states or only graphics mode. The color used for graphics also can be set.

Selecting Graphics

By default, the graphics cursor mode is Select Graphic. In this mode, when the cursor is positioned over an existing graphic (a point, polyline, rectangle, or polygon) and the left mouse-button is clicked, the indicated graphic is selected. When selected, a graphic is highlighted with handles at the knots (e.g., vertices of polygons).

Multiple graphics can be selected with successive control-clicks with the left mouse-button. All graphics can be selected by choosing "Edit->Select All" in graphics mode.

Editing Graphics

The handles of selected graphics can be used to relocate knots by using click-and-drag with the left mouse-button. A selected graphic can be translated in-full by click-and-drag with the left mouse-button, beginning in the interior of the graphic. Multiple selected graphics also can be relocated using click-and-drag with the left mouse-button.

When a graphic is selected, clicking the right mouse-button brings up a graphic metadata popup, in which metadata, such as the name color of the graphic and color, can be assigned. The include flag for a graphic is used in generating reports, e.g., indicating that blobs with peaks contained in a polygon or blobs intersected by a polyline are reported as a peak set. This use of graphics is described more fully in chapters Pattern Recognition and Reports. Figure 5 illustrates the Graphic Metadata dialog.

Figure 5: The Graphic Metadata dialog.

When multiple graphics are selected, clicking the right mouse-button brings up a popup for shared metadata. Figure 6 illustrates the Graphics Metadata dialog for multiple graphics.

Figure 6: The Graphics Metadata dialog for multiple graphics.

Delete Graphic Object

To delete a graphic(s), first enter graphic mode, then select the desired graphic(s), and then click the Delete Object button on the palette. If multiple graphics are selected, all are deleted.

Exporting and Importing Graphics

To export the set of graphic objects in the current image, select Export Graphics Table from the File menu and indicate the filename in the popup dialog.

To import a set of graphic objects previously exported to a file, select Import Graphics Table from the File menu. The user chooses whether the imported graphics are to be appended to any existing graphics or are to replace any existing graphics and indicates the filename in the popup dialog.

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