Class IIOParam

protected IIOParamController controller

The controller called by this IIOParam to retrieve parameters.

protected IIOParamController defaultController

The default controller called by this IIOParam to retrieve parameters.

protected Point destinationOffset

The offset in the destination where the upper-left decoded/encoded pixel should be located.

protected ImageTypeSpecifier destinationType

Sets the output colour type when writing or the destination image type when reading.

protected int[] sourceBands

An array indicating which source bands will be used or null.

protected Rectangle sourceRegion

The source pixel region or null.

protected int sourceXSubsampling

Sample every sourceXSubsampling'th pixel in the source image when pixelating the destination image in the horizontal direction.

protected int sourceYSubsampling

Sample every sourceYSubsampling'th pixel in the source image when pixelating the destination image in the vertical direction.

protected int subsamplingXOffset

Start sampling at this horizontal offset within the source region when pixelating the destination image in the horizontal direction.

protected int subsamplingYOffset

Start sampling at this vertical offset within the source region when pixelating the destination image in the vertical direction.

protected IIOParam()

Constructs an IIOParam object.

public boolean activateController()

Activates the parameter controller by calling its activate method and passing it this IIOParam. A true return value indicates that this IIOParam's values are ready for the next read or write operation. A return value of false means that this IIOParam's values have not been affected because the controller operations were cancelled.

Returns:

true if parameters were successfully set, false if parameters were not changed

public IIOParamController getController()

Retrieve the currently set controller if one has been set, or the default controller, or null if the controller has been explicitly set to null.

Returns:

the currently used controller or null

public IIOParamController getDefaultController()

Retrieve the default controller regardless of whether or not a non-default controller has been set. The default controller may be null.

Returns:

the default controller or null

public Point getDestinationOffset()

Retrieve the offset in the destination where the upper-left decoded/encoded pixel should be located. (0, 0) by default.

Returns:

the destination offset

public ImageTypeSpecifier getDestinationType()

Retrieve the currently set image-type specifier or null if none has been set.

Returns:

the current image-type specifier or null

public int[] getSourceBands()

Retrieve the current source band values or null if source band values have not been set. The returned array is a copy of this IIOParam's source band array.

Returns:

the current set of source band values or null

public Rectangle getSourceRegion()

Retrieve the source rectangle from which pixels should be read or null if no source region has been set.

Returns:

the current source region or null

public int getSourceXSubsampling()

Retrieve the number of pixel columns to advance before taking a pixel sample.

Returns:

the horizontal sub-sampling interval

public int getSourceYSubsampling()

Retrieve the number of pixel rows to advance before taking a pixel sample.

Returns:

the vertical sub-sampling interval

public int getSubsamplingXOffset()

Retrieve the number of pixel columns to advance before taking any pixel samples.

Returns:

the horizontal sub-sampling offset

public int getSubsamplingYOffset()

Retrieve the number of pixel rows to advance before taking any pixel samples.

Returns:

the vertical sub-sampling offset

public boolean hasController()

Check if a non-null controller is currently available.

Returns:

true if getController returns a non-null value, false if getController returns null

public void setController(IIOParamController controller)

Sets the controller for this IIOParam. This is the controller that will be activated when activateController is called. The argument controller overrides this IIOParam's default controller. If the argument is null then no controller will be set, not even the default one. To reset the default controller call setController(getDefaultController()).

Parameters:

controller - the controller to set or null

public void setDestinationOffset(Point destinationOffset)

Specify the destination pixel offset. Image writers are only affected by this setting when ImageWriter.replacePixels is called in which case the offset is into the region of pixels being changed.

Parameters:

destinationOffset - the offset where pixel writing should begin

public void setDestinationType(ImageTypeSpecifier destinationType)

Set the destination image type. If this value is set on an image reader then its read method will return a new BufferedImage of the specified destination type. In this case any destination image set using setDestination() is ignored. If this is set on an image writer then the destination type affects only the colour model of the destination image. The destination type's SampleModel is ignored. The destination type's ColorModel will override the source image's colour model.

Parameters:

destinationType - the sample and colour models of the destination image

public void setSourceBands(int[] sourceBands)

Set the indices of the source bands to be used. Duplicate indices are not allowed. A value of null means use all source bands. The argument array is copied and stored, so subsequent updates to it will not be reflected in this IIOParam.

Parameters:

sourceBands - the array of source bands to use

public void setSourceRegion(Rectangle sourceRegion)

Set the source region from which to read. The number of pixels sampled from the source region depends on the source sub-sampling settings. If the combination of this sourceRegion and the current sub-sampling settings would result in no pixels being sampled then an IllegalStateException will be thrown. The source region is specified in the source image coordinate system which has point (0, 0) at the top-left and increases down and to the right. The argument source region is clipped to the image boundaries at read-time. A null argument sets the source region to null meaning that the whole image should be read.

Parameters:

sourceRegion - the rectangular source region

Throws:

IllegalArgumentException - if sourceRegion has width or height <= 0 or x or y <320

IllegalStateException - if the given sourceRegion and the current sampling settings would produce zero samples

public void setSourceSubsampling(int sourceXSubsampling,
                                 int sourceYSubsampling,
                                 int subsamplingXOffset,
                                 int subsamplingYOffset)

Set the source sampling intervals and offsets. Every sourceXSubsampling'th pixel horizontally and sourceYSubsampling'th pixel vertically will be sampled. Sampling will being a the subsamplingXOffset'th column and the subsamplingYOffset'th row. Horizontally, the number of sampled pixels will be: floor((width - subsamplingXOffset + sourceXSubsampling - 1) / sourceXSubsampling) Vertically: floor((height - subsamplingYOffset + sourceYSubsampling - 1) / sourceYSubsampling) If the current source region setting is such that the given sub-sampling arguments would produce zero pixel samples, an IllegalStateException is thrown. The offset parameters can be used to make source regions overlap when tiling across an image. This can eliminate seams and better-tile images whose width or height is not a multiple of the sampling interval.

Parameters:

sourceXSubsampling - the horizontal sampling interval

sourceYSubsampling - the vertical sampling interval

subsamplingXOffset - the horizontal offset of the initial sample

subsamplingYOffset - the vertical offset of the initial sample

Throws:

IllegalArgumentException - if either subsamplingXOffset or subsamplingYOffset is <320

IllegalStateException - if the current source region combined with the given sub-sampling parameters would produce zero pixel samples