01: /*
02: * Licensed to the Apache Software Foundation (ASF) under one or more
03: * contributor license agreements. See the NOTICE file distributed with
04: * this work for additional information regarding copyright ownership.
05: * The ASF licenses this file to You under the Apache License, Version 2.0
06: * (the "License"); you may not use this file except in compliance with
07: * the License. You may obtain a copy of the License at
08: *
09: * http://www.apache.org/licenses/LICENSE-2.0
10: *
11: * Unless required by applicable law or agreed to in writing, software
12: * distributed under the License is distributed on an "AS IS" BASIS,
13: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14: * See the License for the specific language governing permissions and
15: * limitations under the License.
16: */
17:
18: /* $Id: ImageDecoder.java 447277 2006-09-18 06:19:34Z jeremias $ */
19:
20: package org.apache.xmlgraphics.image.codec.util;
21:
22: import java.awt.image.Raster;
23: import java.awt.image.RenderedImage;
24: import java.io.IOException;
25:
26: /**
27: * An interface describing objects that transform an InputStream into a
28: * BufferedImage or Raster.
29: *
30: */
31: public interface ImageDecoder {
32:
33: /**
34: * Returns the current parameters as an instance of the
35: * ImageDecodeParam interface. Concrete implementations of this
36: * interface will return corresponding concrete implementations of
37: * the ImageDecodeParam interface. For example, a JPEGImageDecoder
38: * will return an instance of JPEGDecodeParam.
39: */
40: ImageDecodeParam getParam();
41:
42: /**
43: * Sets the current parameters to an instance of the
44: * ImageDecodeParam interface. Concrete implementations
45: * of ImageDecoder may throw a RuntimeException if the
46: * param argument is not an instance of the appropriate
47: * subclass or subinterface. For example, a JPEGImageDecoder
48: * will expect param to be an instance of JPEGDecodeParam.
49: */
50: void setParam(ImageDecodeParam param);
51:
52: /** Returns the SeekableStream associated with this ImageDecoder. */
53: SeekableStream getInputStream();
54:
55: /** Returns the number of pages present in the current stream. */
56: int getNumPages() throws IOException;
57:
58: /**
59: * Returns a Raster that contains the decoded contents of the
60: * SeekableStream associated with this ImageDecoder. Only
61: * the first page of a multi-page image is decoded.
62: */
63: Raster decodeAsRaster() throws IOException;
64:
65: /**
66: * Returns a Raster that contains the decoded contents of the
67: * SeekableStream associated with this ImageDecoder.
68: * The given page of a multi-page image is decoded. If
69: * the page does not exist, an IOException will be thrown.
70: * Page numbering begins at zero.
71: *
72: * @param page The page to be decoded.
73: */
74: Raster decodeAsRaster(int page) throws IOException;
75:
76: /**
77: * Returns a RenderedImage that contains the decoded contents of the
78: * SeekableStream associated with this ImageDecoder. Only
79: * the first page of a multi-page image is decoded.
80: */
81: RenderedImage decodeAsRenderedImage() throws IOException;
82:
83: /**
84: * Returns a RenderedImage that contains the decoded contents of the
85: * SeekableStream associated with this ImageDecoder.
86: * The given page of a multi-page image is decoded. If
87: * the page does not exist, an IOException will be thrown.
88: * Page numbering begins at zero.
89: *
90: * @param page The page to be decoded.
91: */
92: RenderedImage decodeAsRenderedImage(int page) throws IOException;
93: }
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