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677 lines
25 KiB
Java
677 lines
25 KiB
Java
/*
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* Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package javax.imageio;
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import java.awt.Point;
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import java.awt.Rectangle;
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/**
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* A superclass of all classes describing how streams should be
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* decoded or encoded. This class contains all the variables and
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* methods that are shared by {@code ImageReadParam} and
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* {@code ImageWriteParam}.
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*
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* <p> This class provides mechanisms to specify a source region and a
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* destination region. When reading, the source is the stream and
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* the in-memory image is the destination. When writing, these are
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* reversed. In the case of writing, destination regions may be used
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* only with a writer that supports pixel replacement.
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* <p>
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* Decimation subsampling may be specified for both readers
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* and writers, using a movable subsampling grid.
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* <p>
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* Subsets of the source and destination bands may be selected.
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*
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*/
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public abstract class IIOParam {
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/**
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* The source region, on {@code null} if none is set.
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*/
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protected Rectangle sourceRegion = null;
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/**
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* The decimation subsampling to be applied in the horizontal
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* direction. By default, the value is {@code 1}.
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* The value must not be negative or 0.
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*/
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protected int sourceXSubsampling = 1;
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/**
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* The decimation subsampling to be applied in the vertical
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* direction. By default, the value is {@code 1}.
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* The value must not be negative or 0.
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*/
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protected int sourceYSubsampling = 1;
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/**
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* A horizontal offset to be applied to the subsampling grid before
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* subsampling. The first pixel to be used will be offset this
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* amount from the origin of the region, or of the image if no
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* region is specified.
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*/
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protected int subsamplingXOffset = 0;
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/**
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* A vertical offset to be applied to the subsampling grid before
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* subsampling. The first pixel to be used will be offset this
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* amount from the origin of the region, or of the image if no
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* region is specified.
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*/
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protected int subsamplingYOffset = 0;
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/**
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* An array of {@code int}s indicating which source bands
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* will be used, or {@code null}. If {@code null}, the
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* set of source bands to be used is as described in the comment
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* for the {@code setSourceBands} method. No value should
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* be allowed to be negative.
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*/
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protected int[] sourceBands = null;
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/**
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* An {@code ImageTypeSpecifier} to be used to generate a
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* destination image when reading, or to set the output color type
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* when writing. If non has been set the value will be
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* {@code null}. By default, the value is {@code null}.
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*/
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protected ImageTypeSpecifier destinationType = null;
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/**
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* The offset in the destination where the upper-left decoded
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* pixel should be placed. By default, the value is (0, 0).
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*/
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protected Point destinationOffset = new Point(0, 0);
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/**
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* The default {@code IIOParamController} that will be
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* used to provide settings for this {@code IIOParam}
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* object when the {@code activateController} method
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* is called. This default should be set by subclasses
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* that choose to provide their own default controller,
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* usually a GUI, for setting parameters.
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*
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* @see IIOParamController
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* @see #getDefaultController
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* @see #activateController
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*/
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protected IIOParamController defaultController = null;
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/**
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* The {@code IIOParamController} that will be
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* used to provide settings for this {@code IIOParam}
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* object when the {@code activateController} method
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* is called. This value overrides any default controller,
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* even when null.
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*
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* @see IIOParamController
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* @see #setController(IIOParamController)
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* @see #hasController()
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* @see #activateController()
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*/
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protected IIOParamController controller = null;
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/**
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* Protected constructor may be called only by subclasses.
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*/
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protected IIOParam() {
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controller = defaultController;
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}
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/**
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* Sets the source region of interest. The region of interest is
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* described as a rectangle, with the upper-left corner of the
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* source image as pixel (0, 0) and increasing values down and to
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* the right. The actual number of pixels used will depend on
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* the subsampling factors set by {@code setSourceSubsampling}.
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* If subsampling has been set such that this number is zero,
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* an {@code IllegalStateException} will be thrown.
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*
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* <p> The source region of interest specified by this method will
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* be clipped as needed to fit within the source bounds, as well
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* as the destination offsets, width, and height at the time of
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* actual I/O.
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*
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* <p> A value of {@code null} for {@code sourceRegion}
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* will remove any region specification, causing the entire image
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* to be used.
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*
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* @param sourceRegion a {@code Rectangle} specifying the
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* source region of interest, or {@code null}.
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*
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* @exception IllegalArgumentException if
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* {@code sourceRegion} is non-{@code null} and either
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* {@code sourceRegion.x} or {@code sourceRegion.y} is
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* negative.
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* @exception IllegalArgumentException if
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* {@code sourceRegion} is non-{@code null} and either
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* {@code sourceRegion.width} or
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* {@code sourceRegion.height} is negative or 0.
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* @exception IllegalStateException if subsampling is such that
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* this region will have a subsampled width or height of zero.
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*
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* @see #getSourceRegion
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* @see #setSourceSubsampling
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* @see ImageReadParam#setDestinationOffset
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* @see ImageReadParam#getDestinationOffset
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*/
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public void setSourceRegion(Rectangle sourceRegion) {
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if (sourceRegion == null) {
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this.sourceRegion = null;
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return;
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}
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if (sourceRegion.x < 0) {
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throw new IllegalArgumentException("sourceRegion.x < 0!");
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}
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if (sourceRegion.y < 0){
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throw new IllegalArgumentException("sourceRegion.y < 0!");
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}
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if (sourceRegion.width <= 0) {
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throw new IllegalArgumentException("sourceRegion.width <= 0!");
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}
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if (sourceRegion.height <= 0) {
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throw new IllegalArgumentException("sourceRegion.height <= 0!");
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}
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// Throw an IllegalStateException if region falls between subsamples
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if (sourceRegion.width <= subsamplingXOffset) {
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throw new IllegalStateException
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("sourceRegion.width <= subsamplingXOffset!");
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}
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if (sourceRegion.height <= subsamplingYOffset) {
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throw new IllegalStateException
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("sourceRegion.height <= subsamplingYOffset!");
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}
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this.sourceRegion = (Rectangle)sourceRegion.clone();
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}
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/**
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* Returns the source region to be used. The returned value is
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* that set by the most recent call to
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* {@code setSourceRegion}, and will be {@code null} if
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* there is no region set.
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*
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* @return the source region of interest as a
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* {@code Rectangle}, or {@code null}.
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*
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* @see #setSourceRegion
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*/
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public Rectangle getSourceRegion() {
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if (sourceRegion == null) {
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return null;
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}
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return (Rectangle)sourceRegion.clone();
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}
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/**
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* Specifies a decimation subsampling to apply on I/O. The
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* {@code sourceXSubsampling} and
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* {@code sourceYSubsampling} parameters specify the
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* subsampling period (<i>i.e.</i>, the number of rows and columns
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* to advance after every source pixel). Specifically, a period of
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* 1 will use every row or column; a period of 2 will use every
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* other row or column. The {@code subsamplingXOffset} and
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* {@code subsamplingYOffset} parameters specify an offset
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* from the region (or image) origin for the first subsampled pixel.
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* Adjusting the origin of the subsample grid is useful for avoiding
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* seams when subsampling a very large source image into destination
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* regions that will be assembled into a complete subsampled image.
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* Most users will want to simply leave these parameters at 0.
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*
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* <p> The number of pixels and scanlines to be used are calculated
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* as follows.
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* <p>
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* The number of subsampled pixels in a scanline is given by
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* <p>
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* {@code truncate[(width - subsamplingXOffset + sourceXSubsampling - 1)
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* / sourceXSubsampling]}.
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* <p>
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* If the region is such that this width is zero, an
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* {@code IllegalStateException} is thrown.
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* <p>
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* The number of scanlines to be used can be computed similarly.
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*
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* <p>The ability to set the subsampling grid to start somewhere
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* other than the source region origin is useful if the
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* region is being used to create subsampled tiles of a large image,
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* where the tile width and height are not multiples of the
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* subsampling periods. If the subsampling grid does not remain
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* consistent from tile to tile, there will be artifacts at the tile
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* boundaries. By adjusting the subsampling grid offset for each
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* tile to compensate, these artifacts can be avoided. The tradeoff
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* is that in order to avoid these artifacts, the tiles are not all
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* the same size. The grid offset to use in this case is given by:
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* <br>
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* grid offset = [period - (region offset modulo period)] modulo period)
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*
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* <p> If either {@code sourceXSubsampling} or
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* {@code sourceYSubsampling} is 0 or negative, an
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* {@code IllegalArgumentException} will be thrown.
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*
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* <p> If either {@code subsamplingXOffset} or
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* {@code subsamplingYOffset} is negative or greater than or
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* equal to the corresponding period, an
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* {@code IllegalArgumentException} will be thrown.
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*
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* <p> There is no {@code unsetSourceSubsampling} method;
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* simply call {@code setSourceSubsampling(1, 1, 0, 0)} to
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* restore default values.
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*
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* @param sourceXSubsampling the number of columns to advance
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* between pixels.
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* @param sourceYSubsampling the number of rows to advance between
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* pixels.
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* @param subsamplingXOffset the horizontal offset of the first subsample
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* within the region, or within the image if no region is set.
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* @param subsamplingYOffset the horizontal offset of the first subsample
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* within the region, or within the image if no region is set.
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* @exception IllegalArgumentException if either period is
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* negative or 0, or if either grid offset is negative or greater than
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* the corresponding period.
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* @exception IllegalStateException if the source region is such that
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* the subsampled output would contain no pixels.
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*/
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public void setSourceSubsampling(int sourceXSubsampling,
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int sourceYSubsampling,
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int subsamplingXOffset,
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int subsamplingYOffset) {
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if (sourceXSubsampling <= 0) {
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throw new IllegalArgumentException("sourceXSubsampling <= 0!");
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}
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if (sourceYSubsampling <= 0) {
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throw new IllegalArgumentException("sourceYSubsampling <= 0!");
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}
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if (subsamplingXOffset < 0 ||
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subsamplingXOffset >= sourceXSubsampling) {
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throw new IllegalArgumentException
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("subsamplingXOffset out of range!");
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}
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if (subsamplingYOffset < 0 ||
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subsamplingYOffset >= sourceYSubsampling) {
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throw new IllegalArgumentException
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("subsamplingYOffset out of range!");
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}
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// Throw an IllegalStateException if region falls between subsamples
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if (sourceRegion != null) {
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if (subsamplingXOffset >= sourceRegion.width ||
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subsamplingYOffset >= sourceRegion.height) {
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throw new IllegalStateException("region contains no pixels!");
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}
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}
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this.sourceXSubsampling = sourceXSubsampling;
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this.sourceYSubsampling = sourceYSubsampling;
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this.subsamplingXOffset = subsamplingXOffset;
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this.subsamplingYOffset = subsamplingYOffset;
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}
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/**
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* Returns the number of source columns to advance for each pixel.
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*
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* <p>If {@code setSourceSubsampling} has not been called, 1
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* is returned (which is the correct value).
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*
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* @return the source subsampling X period.
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*
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* @see #setSourceSubsampling
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* @see #getSourceYSubsampling
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*/
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public int getSourceXSubsampling() {
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return sourceXSubsampling;
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}
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/**
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* Returns the number of rows to advance for each pixel.
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*
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* <p>If {@code setSourceSubsampling} has not been called, 1
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* is returned (which is the correct value).
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*
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* @return the source subsampling Y period.
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*
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* @see #setSourceSubsampling
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* @see #getSourceXSubsampling
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*/
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public int getSourceYSubsampling() {
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return sourceYSubsampling;
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}
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/**
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* Returns the horizontal offset of the subsampling grid.
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*
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* <p>If {@code setSourceSubsampling} has not been called, 0
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* is returned (which is the correct value).
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*
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* @return the source subsampling grid X offset.
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*
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* @see #setSourceSubsampling
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* @see #getSubsamplingYOffset
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*/
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public int getSubsamplingXOffset() {
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return subsamplingXOffset;
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}
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/**
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* Returns the vertical offset of the subsampling grid.
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*
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* <p>If {@code setSourceSubsampling} has not been called, 0
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* is returned (which is the correct value).
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*
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* @return the source subsampling grid Y offset.
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*
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* @see #setSourceSubsampling
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* @see #getSubsamplingXOffset
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*/
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public int getSubsamplingYOffset() {
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return subsamplingYOffset;
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}
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/**
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* Sets the indices of the source bands to be used. Duplicate
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* indices are not allowed.
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*
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* <p> A {@code null} value indicates that all source bands
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* will be used.
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*
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* <p> At the time of reading, an
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* {@code IllegalArgumentException} will be thrown by the
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* reader or writer if a value larger than the largest available
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* source band index has been specified or if the number of source
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* bands and destination bands to be used differ. The
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* {@code ImageReader.checkReadParamBandSettings} method may
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* be used to automate this test.
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*
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* <p> Semantically, a copy is made of the array; changes to the
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* array contents subsequent to this call have no effect on
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* this {@code IIOParam}.
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*
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* @param sourceBands an array of integer band indices to be
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* used.
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*
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* @exception IllegalArgumentException if {@code sourceBands}
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* contains a negative or duplicate value.
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*
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* @see #getSourceBands
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* @see ImageReadParam#setDestinationBands
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* @see ImageReader#checkReadParamBandSettings
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*/
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public void setSourceBands(int[] sourceBands) {
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if (sourceBands == null) {
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this.sourceBands = null;
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} else {
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int numBands = sourceBands.length;
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for (int i = 0; i < numBands; i++) {
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int band = sourceBands[i];
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if (band < 0) {
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throw new IllegalArgumentException("Band value < 0!");
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}
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for (int j = i + 1; j < numBands; j++) {
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if (band == sourceBands[j]) {
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throw new IllegalArgumentException("Duplicate band value!");
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}
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}
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}
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this.sourceBands = (sourceBands.clone());
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}
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}
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/**
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* Returns the set of source bands to be used. The returned
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* value is that set by the most recent call to
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* {@code setSourceBands}, or {@code null} if there have
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* been no calls to {@code setSourceBands}.
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*
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* <p> Semantically, the array returned is a copy; changes to
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* array contents subsequent to this call have no effect on this
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* {@code IIOParam}.
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*
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* @return the set of source bands to be used, or
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* {@code null}.
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*
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* @see #setSourceBands
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*/
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public int[] getSourceBands() {
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if (sourceBands == null) {
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return null;
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}
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return (sourceBands.clone());
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}
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/**
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* Sets the desired image type for the destination image, using an
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* {@code ImageTypeSpecifier}.
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*
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* <p> When reading, if the layout of the destination has been set
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* using this method, each call to an {@code ImageReader}
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* {@code read} method will return a new
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* {@code BufferedImage} using the format specified by the
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* supplied type specifier. As a side effect, any destination
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* {@code BufferedImage} set by
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* {@code ImageReadParam.setDestination(BufferedImage)} will
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* no longer be set as the destination. In other words, this
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* method may be thought of as calling
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* {@code setDestination((BufferedImage)null)}.
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*
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* <p> When writing, the destination type maybe used to determine
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* the color type of the image. The {@code SampleModel}
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* information will be ignored, and may be {@code null}. For
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* example, a 4-banded image could represent either CMYK or RGBA
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* data. If a destination type is set, its
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* {@code ColorModel} will override any
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* {@code ColorModel} on the image itself. This is crucial
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* when {@code setSourceBands} is used since the image's
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* {@code ColorModel} will refer to the entire image rather
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* than to the subset of bands being written.
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*
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* @param destinationType the {@code ImageTypeSpecifier} to
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* be used to determine the destination layout and color type.
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*
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* @see #getDestinationType
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*/
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public void setDestinationType(ImageTypeSpecifier destinationType) {
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this.destinationType = destinationType;
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}
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/**
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* Returns the type of image to be returned by the read, if one
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* was set by a call to
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* {@code setDestination(ImageTypeSpecifier)}, as an
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* {@code ImageTypeSpecifier}. If none was set,
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* {@code null} is returned.
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*
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* @return an {@code ImageTypeSpecifier} describing the
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* destination type, or {@code null}.
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*
|
|
* @see #setDestinationType
|
|
*/
|
|
public ImageTypeSpecifier getDestinationType() {
|
|
return destinationType;
|
|
}
|
|
|
|
/**
|
|
* Specifies the offset in the destination image at which future
|
|
* decoded pixels are to be placed, when reading, or where a
|
|
* region will be written, when writing.
|
|
*
|
|
* <p> When reading, the region to be written within the
|
|
* destination {@code BufferedImage} will start at this
|
|
* offset and have a width and height determined by the source
|
|
* region of interest, the subsampling parameters, and the
|
|
* destination bounds.
|
|
*
|
|
* <p> Normal writes are not affected by this method, only writes
|
|
* performed using {@code ImageWriter.replacePixels}. For
|
|
* such writes, the offset specified is within the output stream
|
|
* image whose pixels are being modified.
|
|
*
|
|
* <p> There is no {@code unsetDestinationOffset} method;
|
|
* simply call {@code setDestinationOffset(new Point(0, 0))} to
|
|
* restore default values.
|
|
*
|
|
* @param destinationOffset the offset in the destination, as a
|
|
* {@code Point}.
|
|
*
|
|
* @exception IllegalArgumentException if
|
|
* {@code destinationOffset} is {@code null}.
|
|
*
|
|
* @see #getDestinationOffset
|
|
* @see ImageWriter#replacePixels
|
|
*/
|
|
public void setDestinationOffset(Point destinationOffset) {
|
|
if (destinationOffset == null) {
|
|
throw new IllegalArgumentException("destinationOffset == null!");
|
|
}
|
|
this.destinationOffset = (Point)destinationOffset.clone();
|
|
}
|
|
|
|
/**
|
|
* Returns the offset in the destination image at which pixels are
|
|
* to be placed.
|
|
*
|
|
* <p> If {@code setDestinationOffsets} has not been called,
|
|
* a {@code Point} with zero X and Y values is returned
|
|
* (which is the correct value).
|
|
*
|
|
* @return the destination offset as a {@code Point}.
|
|
*
|
|
* @see #setDestinationOffset
|
|
*/
|
|
public Point getDestinationOffset() {
|
|
return (Point)destinationOffset.clone();
|
|
}
|
|
|
|
/**
|
|
* Sets the {@code IIOParamController} to be used
|
|
* to provide settings for this {@code IIOParam}
|
|
* object when the {@code activateController} method
|
|
* is called, overriding any default controller. If the
|
|
* argument is {@code null}, no controller will be
|
|
* used, including any default. To restore the default, use
|
|
* {@code setController(getDefaultController())}.
|
|
*
|
|
* @param controller An appropriate
|
|
* {@code IIOParamController}, or {@code null}.
|
|
*
|
|
* @see IIOParamController
|
|
* @see #getController
|
|
* @see #getDefaultController
|
|
* @see #hasController
|
|
* @see #activateController()
|
|
*/
|
|
public void setController(IIOParamController controller) {
|
|
this.controller = controller;
|
|
}
|
|
|
|
/**
|
|
* Returns whatever {@code IIOParamController} is currently
|
|
* installed. This could be the default if there is one,
|
|
* {@code null}, or the argument of the most recent call
|
|
* to {@code setController}.
|
|
*
|
|
* @return the currently installed
|
|
* {@code IIOParamController}, or {@code null}.
|
|
*
|
|
* @see IIOParamController
|
|
* @see #setController
|
|
* @see #getDefaultController
|
|
* @see #hasController
|
|
* @see #activateController()
|
|
*/
|
|
public IIOParamController getController() {
|
|
return controller;
|
|
}
|
|
|
|
/**
|
|
* Returns the default {@code IIOParamController}, if there
|
|
* is one, regardless of the currently installed controller. If
|
|
* there is no default controller, returns {@code null}.
|
|
*
|
|
* @return the default {@code IIOParamController}, or
|
|
* {@code null}.
|
|
*
|
|
* @see IIOParamController
|
|
* @see #setController(IIOParamController)
|
|
* @see #getController
|
|
* @see #hasController
|
|
* @see #activateController()
|
|
*/
|
|
public IIOParamController getDefaultController() {
|
|
return defaultController;
|
|
}
|
|
|
|
/**
|
|
* Returns {@code true} if there is a controller installed
|
|
* for this {@code IIOParam} object. This will return
|
|
* {@code true} if {@code getController} would not
|
|
* return {@code null}.
|
|
*
|
|
* @return {@code true} if a controller is installed.
|
|
*
|
|
* @see IIOParamController
|
|
* @see #setController(IIOParamController)
|
|
* @see #getController
|
|
* @see #getDefaultController
|
|
* @see #activateController()
|
|
*/
|
|
public boolean hasController() {
|
|
return (controller != null);
|
|
}
|
|
|
|
/**
|
|
* Activates the installed {@code IIOParamController} for
|
|
* this {@code IIOParam} object and returns the resulting
|
|
* value. When this method returns {@code true}, all values
|
|
* for this {@code IIOParam} object will be ready for the
|
|
* next read or write operation. If {@code false} is
|
|
* returned, no settings in this object will have been disturbed
|
|
* (<i>i.e.</i>, the user canceled the operation).
|
|
*
|
|
* <p> Ordinarily, the controller will be a GUI providing a user
|
|
* interface for a subclass of {@code IIOParam} for a
|
|
* particular plug-in. Controllers need not be GUIs, however.
|
|
*
|
|
* @return {@code true} if the controller completed normally.
|
|
*
|
|
* @exception IllegalStateException if there is no controller
|
|
* currently installed.
|
|
*
|
|
* @see IIOParamController
|
|
* @see #setController(IIOParamController)
|
|
* @see #getController
|
|
* @see #getDefaultController
|
|
* @see #hasController
|
|
*/
|
|
public boolean activateController() {
|
|
if (!hasController()) {
|
|
throw new IllegalStateException("hasController() == false!");
|
|
}
|
|
return getController().activate(this);
|
|
}
|
|
}
|