Image Tool

Activate the Image tool to open a dialog window that allows to browse the content of your device and select the image file that will be inserted in the Graphics View. On mobile and Web versions it is also possible to import live images from the camera.

Transparent GIF and PNG files are supported, but for PNGs it is necessary to make sure that they have an alpha channel (for example if editing is made using IrfanView, save using the PNGOUT plugin and choose RGB+Alpha)
Inserted images will be auxiliary objects by default.

Position and Properties of Images

The position of an image can be absolute on screen or relative to the coordinate system: this setting can be specified in the Position tab of the Properties Dialog of the image.

GeoGebra creates automatically 2 points at the bottom corners of the image, that can be used to place and resize the image. These points are defined in the settings as:

Corner 1: position of the bottom left corner of the image
Corner 2: position of the bottom right corner of the image

You can specify up to three corner points of the image in the Position tab of the Properties Dialog of the image. This gives you the flexibility to scale, rotate, and distort images (see also the Corner command). Besides the previous ones, it is possible to define the

Corner 4: position of the upper left corner of the image

Corner 2 controls the width of the image, and Corner 4 controls the height of the image. Both of them can be set only if Corner 1 has been set before.

Create three points A, B, and C and insert an image into the Graphics View to explore the effects of the corner points.

Set point A as the first and point B as the second corner of your image. Activate the Move tool and drag points A and B to change the width of the image.
Now, remove point B as the second corner of the image. Set point A as the first and point C as the fourth corner and explore how dragging the points now influences the height of the image.
Finally, set all three corner points and see how dragging the points distorts your image.

In order to attach your image to a point A, and set its size (e.g. width = 3 and height = 4 units):

Set Corner 1 to A
Set Corner 2 to A + (3, 0)
Set Corner 4 to A + (0, 4)

If you activate the Move tool and drag point A, the size of your image does not change.

You may specify an image as a Background image in the Basic tab of the Properties Dialog of the image. A background image lies behind the coordinate axes and becomes non selectable.

In order to change the background setting of an image, open the Properties Dialog of the image by selecting Object Properties from the Edit Menu. In the Web version and the apps, it is necessary to check the Show Auxiliary Objects option in the Algebra View properties first, so the image is displayed in the list of objects in the Algebra View, then select the image in the Algebra View, and open its Properties dialog.

The Opacity of an image can be changed in order to see objects or axes that lie behind the image: use the slider to specify an Opacity value between 0 and 100 in the Color tab of the Properties Dialog of the image.