DisplayImg

DESCRIPTION

This module displays 2D lattices as images. Multiple inputs may be fanned in to this module, and the input objects will be separately managed and updated.

Lattices of any datatype and any number of channels are allowed. Single-channel input is displayed as monochrome. Three-channel input is displayed as RGB. Four-channel input is interpreted as RGBA, but the alpha channel is not used.

Other numbers of channels (two, or greater than four) will not be displayed correctly. The ImageVision error color, yellow, will be displayed in these cases.

If the lattice coordinates are not uniform, the lattice will be displayed at the sampling resolution. If the lattice coordinates are uniform, the bounding box coordinates will be used to correct the pixel aspect.

To pan an image, drag it with the left mouse button held down. To zoom an image, select it by clicking with the left mouse button and use the dial to get the desired zoom factor.

The stacking order of the images may be changed by using the Page Up and Page Down keys on the numeric keypad (not the editing keys) while the cursor is over the desired image. An image may be moved to the window origin by selecting it with the left mouse button and then pressing the Home key on the numeric keypad while the cursor is over the image. Pressing the Home key when the cursor is not over any image returns all images to the window origin.

To accommodate keyboards which do not have recognizable Page Up, Page Down and Home keys, the following keyboard keys will also work with DisplayImg:

H or h as synonyms for Home
U, u, R, r, P or p as synonyms for Page Up
D, d, L, l, N or n as synonyms for Page Down

The snap button outputs the current display as an RGB lattice. The lattice size will be the size of the display window.

INPUTS

Port: Img In
Type: Lattice
Optional: This port is optional.
Constraints: 2..3-D

This is a multiplexed port that takes in lattices to be displayed.

Port: Background
Type: Parameter
Optional: This port is optional.

Color string used to override the default (black) background color.

WIDGETS

Port: Window
Type: Drawing Area

Port: Zoom
Type: Slider

This parameter sets the zoom factor on the selected image.

Port: Snap?
Type: Button

This parameter outputs the current display as a lattice on the output port.

Port: Remap
Type: Check Box

This parameter remaps the pixel values on the selected image for display purposes. Remap can be used when data value is outside the range of 0 to 255.

OUTPUTS

Port: Img Out
Type: Lattice
Constraints: 2-D
Constraints: 3..4-vector
Constraints: byte
Constraints: uniform

An RGB screen dump of the image.

Port: Pick
Type: Pick

Picked point.

KNOWN PROBLEMS

1.  The current image is not highlighted.

2.  There is a VGX rectwrite bug that causes garbage to be left on the
    screen when panning.

3.  The zoom min and max are not restored from one image to another.
    If the zoom factor of a newly selected image is outside the dial range,
    the dial display will be incorrect.

4.  If the display window is partially or completely obscured by other
    windows, the image output data may be corrupted.

SEE ALSO

ReadImg, WriteImg


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