Image Properties (GNU Octave (version 11.0.90))

#### 15.3.3.7 Image Properties ¶

Properties of `image` objects (see image):

#### Categories: ¶

Callback Execution | Creation/Deletion | Display | Image Data | Mouse Interaction | Object Identification | Parent/Children

#### Callback Execution ¶

`busyaction`: `"cancel"` | {`"queue"`} ¶

  Define how Octave handles the execution of this object’s callback properties when it is unable to interrupt another object’s executing callback. This is only relevant when the currently executing callback object has its `interruptible` property set to `"off"`. The `busyaction` property of the interrupting callback object indicates whether the interrupting callback is queued (`"queue"` (default)) or discarded (`"cancel"`). See Callbacks section.

`interruptible`: `"off"` | {`"on"`} ¶

  Specify whether this object’s callback functions may be interrupted by other callbacks. By default `interruptible` is `"on"` and callbacks that make use of `drawnow`, `figure`, `waitfor`, `getframe` or `pause` functions are eventually interrupted. See Callbacks section.

#### Creation/Deletion ¶

`beingdeleted`: {`"off"`} | `"on"` ¶

  Property indicating that a function has initiated deletion of the object. `beingdeleted` is set to true until the object no longer exists.

`createfcn`: string | function handle, def. `[](0x0)` ¶

  Callback function executed immediately after image has been created. Function is set by using default property on root object, e.g., `set (groot, "defaultimagecreatefcn", 'disp ("image created!")')`.

  For information on how to write graphics listener functions see Callbacks section.

`deletefcn`: string | function handle, def. `[](0x0)` ¶

  Callback function executed immediately before image is deleted.

  For information on how to write graphics listener functions see Callbacks section.

#### Display ¶

`clipping`: `"off"` | {`"on"`} ¶

  If `clipping` is `"on"`, the image is clipped in its parent axes limits.

`visible`: `"off"` | {`"on"`} ¶

  If `visible` is `"off"`, the image is not rendered on screen.

#### Image Data ¶

`alphadata`: scalar | matrix, def. `1` ¶

  Transparency is not yet implemented for image objects. `alphadata` is unused.

`alphadatamapping`: `"direct"` | {`"none"`} | `"scaled"` ¶

  Transparency is not yet implemented for image objects. `alphadatamapping` is unused.

`cdata`: array, def. 64-by-64 double ¶

  Color data for the image object. Data is either stored as a 2-D matrix where each element’s value determines that pixel’s color according to the current colormap, or as a 3-D array where the third dimension contains separate red, blue, and green components for each pixel. For RGB arrays, the values that map to minimum and maximum color value depend on the class of `"cdata"`. Floating point and logical values range from 0 to 1 while integer value range from `intmin` to `intmax` for that integer class.

`cdatamapping`: {`"direct"`} | `"scaled"` ¶

  Sets the method for mapping data from the `"cdata"` property to the current colormap. `"Direct"` mapping selects the color using the `"cdata"` value as an index to the current colormap. `"Scaled"` mapping scales the `"cdata"` values to the range specified in the `"clim"` axes property.

`xdata`: two-element vector, def. `[1 64]` ¶

  Two-element vector `[xfirst xlast]` specifying the x coordinates of the centers of the first and last columns of the image.

  Setting `xdata` to the empty matrix ([]) will restore the default value of `[1 columns(image)]`.

`ydata`: two-element vector, def. `[1 64]` ¶

  Two-element vector `[yfirst ylast]` specifying the y coordinates of the centers of the first and last rows of the image.

  Setting `ydata` to the empty matrix ([]) will restore the default value of `[1 rows(image)]`.

#### Mouse Interaction ¶

`buttondownfcn`: string | function handle, def. `[](0x0)` ¶

  For information on how to write graphics listener functions see Callbacks section.

`contextmenu`: graphics handle, def. `[](0x0)` ¶

  Graphics handle of the uicontextmenu object that is currently associated to this image object.

`hittest`: `"off"` | {`"on"`} ¶

  Specify whether image processes mouse events or passes them to ancestors of the object. When enabled, the object may respond to mouse clicks by evaluating the `"buttondownfcn"`, showing the uicontextmenu, and eventually becoming the root `"currentobject"`. This property is only relevant when the object can accept mouse clicks which is determined by the `"pickableparts"` property. See pickableparts property.

`pickableparts`: `"all"` | `"none"` | {`"visible"`} ¶

  Specify whether image will accept mouse clicks. By default, `pickableparts` is `"visible"` and only visible parts of the image or its children may react to mouse clicks. When `pickableparts` is `"all"` both visible and invisible parts (or children) may react to mouse clicks. When `pickableparts` is `"none"` mouse clicks on the object are ignored and transmitted to any objects underneath this one. When an object is configured to accept mouse clicks the `"hittest"` property will determine how they are processed. See hittest property.

`selected`: {`"off"`} | `"on"` ¶

  Property indicates whether this image is selected.

`selectionhighlight`: `"off"` | {`"on"`} ¶

  If `selectionhighlight` is `"on"`, then the image’s selection state is visually highlighted.

#### Object Identification ¶

`tag`: string, def. `""` ¶

  A user-defined string to label the graphics object.

`type` (read-only): string ¶

  Class name of the graphics object. `type` is always `"image"`.

`userdata`: Any Octave data, def. `[](0x0)` ¶

  User-defined data to associate with the graphics object.

#### Parent/Children ¶

`children` (read-only): vector of graphics handles, def. `[](0x0)` ¶

  Child objects of Images is not yet implemented for image objects. `children` is unused.

`handlevisibility`: `"callback"` | `"off"` | {`"on"`} ¶

  If `handlevisibility` is `"off"`, the image’s handle is not visible in its parent’s `"children"` property.

`parent`: graphics handle ¶

  Handle of the parent graphics object.