PDS Imaging Node
Display Dictionary

• Hierarchical Listing of Classes
• Alphabetical Listing of Classes
• Alphabetical Listing of Attributes
• Class Definitions
• Attribute Dictionary

This dictionary contains classes that provide display parameters for rendering Array data on various display devices. The attributes described herein provide default values suggested by the data provider for display applications and are not to be interpreted as definitive for scientific purposes. Parameters relevant to scientific interpretation are found in classes described elsewhere.

• Default_Display_Settings

• local_identifier_reference
• comment
• horizontal_display_axis
• horizontal_display_direction
• vertical_display_axis
• vertical_display_direction

• Default_Display_Settings_Color

• color_display_axis
• red_channel_band
• green_channel_band
• blue_channel_band

• Default_Display_Settings_Color_Movie

• time_display_axis
• frame_rate
• loop_flag
• loop_count
• loop_delay
• loop_back_and_forth_flag

• Default_Display_Settings_Movie

• time_display_axis
• frame_rate
• loop_flag
• loop_count
• loop_delay
• loop_back_and_forth_flag

• Default_Display_Settings
• Default_Display_Settings_Color
• Default_Display_Settings_Color_Movie
• Default_Display_Settings_Movie

• blue_channel_band
• color_display_axis
• comment
• frame_rate
• green_channel_band
• horizontal_display_axis
• horizontal_display_direction
• local_identifier_reference
• loop_back_and_forth_flag
• loop_count
• loop_delay
• loop_flag
• red_channel_band
• time_display_axis
• vertical_display_axis
• vertical_display_direction

Default_Display_Settings

Class Description: The Default_Display_Settings class provides parameters with default values for the display of a generic Array object on a given display device.

	Entity	Card	Value/Class
Hierarchy	pds:Tagged_NonDigital_Object
	. Default_Display_Settings
Subclasses	Default_Display_Settings_Color
	Default_Display_Settings_Movie
Attributes	local_identifier_reference	1
	comment	0..1
	horizontal_display_axis	1
	horizontal_display_direction	1	Right Left
	vertical_display_axis	1
	vertical_display_direction	1	Down Up
Associations	none

Default_Display_Settings_Color

Class Description: The Default_Display_Settings_Color class provides parameters with default values for the display of a multi-banded Array object in the red, green, and blue channels of a display device.

	Entity	Card	Value/Class
Hierarchy	pds:Tagged_NonDigital_Object
	. Default_Display_Settings
	. . Default_Display_Settings_Color
Subclasses	Default_Display_Settings_Color_Movie
Attributes	color_display_axis	1
	red_channel_band	1
	green_channel_band	1
	blue_channel_band	1
Associations	none

Default_Display_Settings_Color_Movie

Class Description: The Default_Display_Settings_Color_Movie class provides parameters settings default values for the display of an Array object containing both color bands and frames designed to be displayed consecutively on a display device capable of display video content.

	Entity	Card	Value/Class
Hierarchy	pds:Tagged_NonDigital_Object
	. Default_Display_Settings
	. . Default_Display_Settings_Color
	. . . Default_Display_Settings_Color_Movie
Subclasses	none
Attributes	time_display_axis	1
	frame_rate	0..1
	loop_flag	0..1	true false
	loop_count	0..1
	loop_delay	0..1
	loop_back_and_forth_flag	0..1	true false
Associations	none

Default_Display_Settings_Movie

Class Description: The Default_Display_Settings_Movie class provides parameters setting default values for the display of an Array_3D_Movie object using a software application capable of displaying video content.

	Entity	Card	Value/Class
Hierarchy	pds:Tagged_NonDigital_Object
	. Default_Display_Settings
	. . Default_Display_Settings_Movie
Subclasses	none
Attributes	time_display_axis	1
	frame_rate	0..1
	loop_flag	0..1	true false
	loop_count	0..1
	loop_delay	0..1
	loop_back_and_forth_flag	0..1	true false
Associations	none

blue_channel_band

The blue_channel_band attribute identifies the number of the band, along the band axis, that should be loaded, by default, into the blue channel of a display device. The first band along the band axis has band number 1.

Type: ASCII_Integer
Minimum Value: 1
Nillable: false
Steward: img
Name Space Id: disp


color_display_axis

The color_display_axis attribute identifies, by name, the axis of an Array (or Array subclass) that is intended to be displayed in the color dimension of a display device. I.e., bands from this dimension will be loaded into the red, green, and blue bands of the display device. The value of this attribute must match the value of one, and only one, axis_name attribute in an Axis_Array class of the associated Array.

Type: ASCII_Short_String_Collapsed
Nillable: false
Steward: img
Name Space Id: disp


comment

The comment attribute is a free form text string providing additional details related to default display parameters.

Type: ASCII_Text_Preserved
Nillable: false
Steward: img
Name Space Id: disp


frame_rate

The frame_rate attribute indicates the number of still pictures (or frames) that should be displayed per unit of time in a video. Note this is NOT necessarily the same as the rate at which the images were acquired.

Type: ASCII_Real
Unit of Measure Type: Units_of_Frame_Rate
Minimum Value: 1.0
Nillable: false
Steward: img
Name Space Id: disp


green_channel_band

The green_channel_band attribute identifies the number of the band, along the band axis, that should be loaded, by default, into the green channel of a display device. The first band along the band axis has band number 1.

Type: ASCII_Integer
Minimum Value: 1
Nillable: false
Steward: img
Name Space Id: disp


horizontal_display_axis

The horizontal_display_axis attribute identifies, by name, the axis of an Array (or Array subclass) that is intended to be displayed in the horizontal or "sample" dimension on a display device. The value of this attribute must match the value of one, and only one, axis_name attribute in an Axis_Array class of the associated Array.

Type: ASCII_Short_String_Collapsed
Nillable: false
Steward: img
Name Space Id: disp


horizontal_display_direction

The horizontal_display_direction attribute specifies the direction across the screen of a display device that data along the horizontal axis of an Array is supposed to be displayed.

Type: ASCII_Short_String_Collapsed
Minimum Characters: 4
Maximum Characters: 5
Nillable: false
Steward: img
Name Space Id: disp


Values:
- Right - The lowest indexed element along an array axis should be displayed at the left edge of a display device and elements with higher indices should be displayed further to the right. Note that this is the standard display direction for most major image formats.
- Left - The lowest indexed element along an array axis should be displayed at the right edge of a display device and elements with higher indices should be displayed further to the left. Note that virtually no image display formats use this display direction. Use this only when deliberately mirroring the image around the vertical axis.


local_identifier_reference

The local_identifier_reference attribute provides the local_identifier of the digital object described by the referencing class (in this case, the Default_Display_Settings class). Note that a local_identifier attribute, with the same value as this local_identifier_reference, must be present within the label.

Type: ASCII_Short_String_Collapsed
Nillable: false
Steward: img
Name Space Id: disp


loop_back_and_forth_flag

The loop_back_and_forth_flag attribute specifies whether or not a movie should only be "looped" or played repeatedly in the forward direction, or whether it should be played forward followed by played in reverse, iteratively.

Type: ASCII_Boolean
Nillable: false
Steward: img
Name Space Id: disp


Values:
- true - When looping, the movie should be played in the forward direction, followed by the reverse direction, iteratively.
- false - When looping, the movie should only be played in the forward direction. This is the default behavior.


loop_count

The loop_count attribute specifies the number of times a movie should be "looped" or replayed before stopping.

Type: ASCII_Integer
Minimum Value: 1
Nillable: false
Steward: img
Name Space Id: disp


loop_delay

The loop_delay attribute specifies the amount of time to pause between "loops" or repeated playbacks of a movie.

Type: ASCII_Real
Unit of Measure Type: Units_of_Time
Minimum Value: 0.0
Nillable: false
Steward: img
Name Space Id: disp


loop_flag

The loop_flag attribute specifies whether or not a movie object should be played repeatedly without prompting from the user.

Type: ASCII_Boolean
Nillable: false
Steward: img
Name Space Id: disp


Values:
- true - The movie should be "looped" or played repeatedly.
- false - The movie should be not be "looped" or played repeatedly.


red_channel_band

The red_channel_band attribute identifies the number of the band, along the band axis, that should be loaded, by default, into the red channel of a display device. The first band along the band axis has band number 1.

Type: ASCII_Integer
Minimum Value: 1
Nillable: false
Steward: img
Name Space Id: disp


time_display_axis

The time_display_axis attribute identifies, by name, the axis of an Array (or Array subclass), the bands of which are intended to be displayed sequentially in time on a display device. The frame_rate attribute, if present, provides the rate at which these bands are to be displayed.

Type: ASCII_Short_String_Collapsed
Nillable: false
Steward: img
Name Space Id: disp


vertical_display_axis

The vertical_display_axis attribute identifies, by name, the axis of an Array (or Array subclass) that is intended to be displayed in the vertical or "line" dimension on a display device. The value of this attribute must match the value of one, and only one, axis_name attribute in an Axis_Array class of the associated Array.

Type: ASCII_Short_String_Collapsed
Nillable: false
Steward: img
Name Space Id: disp


vertical_display_direction

The vertical_display_direction attribute specifies the direction along the screen of a display device that data along the vertical axis of an Array is supposed to be displayed.

Type: ASCII_Short_String_Collapsed
Minimum Characters: 2
Maximum Characters: 4
Nillable: false
Steward: img
Name Space Id: disp


Values:
- Down - The lowest indexed element along an array axis should be displayed at the top edge of a display device and elements with higher indices should be displayed lower down. This is the display direction typically used for VICAR formatted data.
- Up - The lowest indexed element along an array axis should be displayed at the bottom edge of a display device and elements with higher indices should be displayed higher up. This is the display direction typically used for FITS formatted data.