Image Stimulus

Description

An image stimulus loaded from any standard-format image file.

Note: To preserve the image’s aspect ratio on screen, x_size and y_size must be equal. When drawn, the larger dimension spans the full specified size, while the smaller dimension is scaled to maintain the aspect ratio.

Signature

stimulus/image_file

Required Parameters

path

Examples:
images/image1.png
/path/to/image.png

Filesystem path to the image file

Optional Parameters

alpha_multiplier

Default:1.0

Controls the transparency of the stimulus. 1.0 is fully opaque, while 0.0 is fully tranparent.

x_size

Example:5.0

Horizontal size (degrees).

If omitted, the value of y_size is used. It is an error to omit both x_size and y_size (unless fullscreen is YES).

y_size

Example:5.0

Vertical size (degrees).

If omitted, the value of x_size is used. It is an error to omit both x_size and y_size (unless fullscreen is YES).

x_position

Default:0.0

Horizontal center position (degrees)

y_position

Default:0.0

Vertical center position (degrees)

rotation

Default:0.0

Rotation (degrees)

fullscreen

Default:NO

If YES, the stimulus is sized to fill the display. In this mode, x_size, y_size, x_position, y_position, and rotation are ignored.

deferred

Options:
no
yes
explicit
Default:no

Controls when the stimulus is loaded. If no, the stimulus is loaded at experiment load time. If yes, the stimulus is loaded the first time it is queued. If explicit, the stimulus must be loaded explictly with Load Stimulus.