textrecordimagereader.html

Geotools是一个开源的Java GIS工具包,可利用它来开发符合标准的地理信息系统。Geotools提供了OGC(Open Geospatial Consortium)规范的一个实现来作为他们的

 <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/Reader.html" title="class or interface in java.io"><CODE>Reader</CODE></A>, <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/InputStream.html" title="class or interface in java.io"><CODE>InputStream</CODE></A> or
 <A HREF="http://java.sun.com/j2se/1.4/docs/api/javax/imageio/stream/ImageInputStream.html" title="class or interface in javax.imageio.stream"><CODE>ImageInputStream</CODE></A>.
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../org/geotools/image/io/TextImageReader.html#setInput(java.lang.Object, boolean, boolean)">setInput</A></CODE> in class <CODE><A HREF="../../../../org/geotools/image/io/TextImageReader.html" title="class in org.geotools.image.io">TextImageReader</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>input</CODE> - The input object to use for future decoding.<DD><CODE>seekForwardOnly</CODE> - If , images and metadata may only be read
                        in ascending order from this input source.<DD><CODE>ignoreMetadata</CODE> - If , metadata may be ignored during reads.</DL>
</DD>
</DL>
<HR>

<A NAME="getNumBands(int)"><!-- --></A><H3>
getNumBands</H3>
<PRE>
public int <B>getNumBands</B>(int&nbsp;imageIndex)
                throws <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></PRE>
<DL>
<DD>Returns the number of bands available for the specified image.
<P>
<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../../org/geotools/image/io/SimpleImageReader.html#getNumBands(int)">getNumBands</A></CODE> in class <CODE><A HREF="../../../../org/geotools/image/io/SimpleImageReader.html" title="class in org.geotools.image.io">SimpleImageReader</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>imageIndex</CODE> - The image index.
<DT><B>Throws:</B>
<DD><CODE><A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></CODE> - if an error occurs reading the information from the input source.</DL>
</DD>
</DL>
<HR>

<A NAME="getWidth(int)"><!-- --></A><H3>
getWidth</H3>
<PRE>
public int <B>getWidth</B>(int&nbsp;imageIndex)
             throws <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></PRE>
<DL>
<DD>Returns the width in pixels of the given image within the input source.
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>imageIndex</CODE> - the index of the image to be queried.
<DT><B>Returns:</B><DD>Image width.
<DT><B>Throws:</B>
<DD><CODE><A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></CODE> - If an error occurs reading the width information from the input source.</DL>
</DD>
</DL>
<HR>

<A NAME="getHeight(int)"><!-- --></A><H3>
getHeight</H3>
<PRE>
public int <B>getHeight</B>(int&nbsp;imageIndex)
              throws <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></PRE>
<DL>
<DD>Returns the height in pixels of the given image within the input source.
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>imageIndex</CODE> - the index of the image to be queried.
<DT><B>Returns:</B><DD>Image height.
<DT><B>Throws:</B>
<DD><CODE><A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></CODE> - If an error occurs reading the height information from the input source.</DL>
</DD>
</DL>
<HR>

<A NAME="getLogicalBounds(int)"><!-- --></A><H3>
getLogicalBounds</H3>
<PRE>
public <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/awt/geom/Rectangle2D.html" title="class or interface in java.awt.geom">Rectangle2D</A> <B>getLogicalBounds</B>(int&nbsp;imageIndex)
                             throws <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></PRE>
<DL>
<DD>Returns the smallest bounding box containing the full image in user coordinates.
 The default implementation search for minimum and maximum values in <var>x</var>
 and <var>y</var> columns (as returned by <A HREF="../../../../org/geotools/image/io/TextRecordImageReader.html#getColumnX(int)"><CODE>getColumnX(int)</CODE></A> and <A HREF="../../../../org/geotools/image/io/TextRecordImageReader.html#getColumnY(int)"><CODE>getColumnY(int)</CODE></A>)
 and returns a rectangle containing <code>(xmin-dx/2,&nbsp;ymin-dy/2)</code>) and
 <code>(xmax+dx/2,&nbsp;ymax+dy/2)</code>) points, where <var>dx</var> and
 <var>dy</var> are grid cell width and height (i.e. the smallest interval between
 <var>x</var> and <var>y</var> values).
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>imageIndex</CODE> - the index of the image to be queried.
<DT><B>Returns:</B><DD>Image bounds in user coordinates.
<DT><B>Throws:</B>
<DD><CODE><A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></CODE> - If an error occurs reading the width information from the input source.</DL>
</DD>
</DL>
<HR>

<A NAME="getTransform(int)"><!-- --></A><H3>
getTransform</H3>
<PRE>
public <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/awt/geom/AffineTransform.html" title="class or interface in java.awt.geom">AffineTransform</A> <B>getTransform</B>(int&nbsp;imageIndex)
                             throws <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></PRE>
<DL>
<DD>Returns an <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/awt/geom/AffineTransform.html" title="class or interface in java.awt.geom"><CODE>AffineTransform</CODE></A> for transforming pixel coordinates to logical coordinates.
 Pixel coordinates are usually integer values with (0,0) at the image's upper-left corner,
 while logical coordinates are floating point values at the pixel's upper-left corner. The
 later is consistent with <a href="http://java.sun.com/products/java-media/jai/">Java
 Advanced Imaging</a> convention. In order to get logical values at the pixel center,
 a translation must be apply once as below:

 <blockquote><pre>
 AffineTransform tr = getTransform(imageIndex);
 tr.translate(0.5, 0.5);
 </pre></blockquote>

 The default implementation computes the affine transform from <A HREF="../../../../org/geotools/image/io/TextRecordImageReader.html#getLogicalBounds(int)"><CODE>getLogicalBounds(int)</CODE></A>,
 <A HREF="../../../../org/geotools/image/io/TextRecordImageReader.html#getWidth(int)"><CODE>getWidth(int)</CODE></A> and <A HREF="../../../../org/geotools/image/io/TextRecordImageReader.html#getHeight(int)"><CODE>getHeight(int)</CODE></A>.
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>imageIndex</CODE> - the index of the image to be queried.
<DT><B>Returns:</B><DD>A transform mapping pixel coordinates to logical coordinates.
<DT><B>Throws:</B>
<DD><CODE><A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></CODE> - if an I/O operation failed.</DL>
</DD>
</DL>
<HR>

<A NAME="getExpectedRange(int, int)"><!-- --></A><H3>
getExpectedRange</H3>
<PRE>
public <A HREF="http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/util/Range.html" title="class or interface in javax.media.jai.util">Range</A> <B>getExpectedRange</B>(int&nbsp;imageIndex,
                              int&nbsp;band)
                       throws <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></PRE>
<DL>
<DD>Returns the range of values for the specified band.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="../../../../org/geotools/image/io/SimpleImageReader.html#getExpectedRange(int, int)">getExpectedRange</A></CODE> in class <CODE><A HREF="../../../../org/geotools/image/io/SimpleImageReader.html" title="class in org.geotools.image.io">SimpleImageReader</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>imageIndex</CODE> - The image index.<DD><CODE>band</CODE> - The band index. Valid index goes from  inclusive
         to  exclusive. Index are independent
         of any <A HREF="http://java.sun.com/j2se/1.4/docs/api/javax/imageio/IIOParam.html#setSourceBands(int[])" title="class or interface in javax.imageio"><CODE>IIOParam.setSourceBands(int[])</CODE></A> setting.
<DT><B>Returns:</B><DD>The expected range of values, or  if unknow.
<DT><B>Throws:</B>
<DD><CODE><A HREF="http://java.sun.com/j2se/1.4/docs/api/java/io/IOException.html" title="class or interface in java.io">IOException</A></CODE> - If an error occurs reading the data information from the input source.</DL>
</DD>
</DL>
<HR>

<A NAME="parseLine(java.lang.String, double[])"><!-- --></A><H3>
parseLine</H3>
<PRE>
protected double[] <B>parseLine</B>(<A HREF="http://java.sun.com/j2se/1.4/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A>&nbsp;line,
                             double[]&nbsp;values)
                      throws <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/text/ParseException.html" title="class or interface in java.text">ParseException</A></PRE>
<DL>
<DD>Converts a line from the <A HREF="http://java.sun.com/j2se/1.4/docs/api/javax/imageio/ImageReader.html#input" title="class or interface in javax.imageio">input</A> stream to numerical values. This method
 is invoked automatically for each line to be read. The default implementation parse the line
 using the object created by <A HREF="../../../../org/geotools/image/io/TextImageReader.html#getLineFormat(int)"><CODE>TextImageReader.getLineFormat(int)</CODE></A>, and replace all occurences of the
 <A HREF="../../../../org/geotools/image/io/TextImageReader.html#getPadValue(int)">pad value</A> by <A HREF="http://java.sun.com/j2se/1.4/docs/api/java/lang/Double.html#NaN" title="class or interface in java.lang"><CODE>Double.NaN</CODE></A> in every columns except the ones
 for <A HREF="../../../../org/geotools/image/io/TextRecordImageReader.html#getColumnX(int)">x</A> and <A HREF="../../../../org/geotools/image/io/TextRecordImageReader.html#getColumnY(int)">y</A> values.
 <p>
 <strong>TIP:</strong> This method is a convenient place where to fix rounding error in
 latitude and longitude coordinates. For example if longitude have a step 1/6