image enhancement.htm

是一部关于java高级图像处理的的一本入门书

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    <P></P></DD></DL>This example provides a non-linear amplitude transformation 
  between input and output pixel values, in which the smaller input amplitude 
  values are amplified and the larger input values are attenuated. Other types 
  of lookup values can be used to solve nearly any non-linear amplitude scaling 
  problem. 
  <P><A name=51408>
  <H3>7.6.1 <IMG src="Image Enhancement.files/space.gif">Creating the Lookup 
  Table</H3></A>The <CODE>LookupTableJAI</CODE> object represents a single- or 
  multi-banded table or a color cube of any supported data types. A single- or 
  multi-banded source image of integer data types is passed through the table 
  and transformed into a single- or multi-banded destination image of both 
  integral and float or double data types. 
  <P>The <CODE>LookupTableJAI</CODE> object is used for the 
  <CODE>ErrorDiffusion</CODE> operation, where it describes a color map, and the 
  <CODE>Lookup</CODE> operation, where it describes the lookup table. For the 
  <CODE>Lookup</CODE> operation, the table data may cover only a subrange of the 
  legal range of the input data type. The subrange is selected by means of an 
  offset parameter that is to be subtracted from the input value before indexing 
  into the table array. 
  <P>The procedures for constructing a lookup table vary slightly, depending on 
  whether the input image is single-banded or multi-banded. For a single-band 
  input image, you construct a single lookup table. For a multi-band image, you 
  construct a single lookup table with entries for each band. 
  <P><A name=56774>
  <H4>7.6.1.1 <IMG src="Image Enhancement.files/space.gif">Creating a 
  Single-band Lookup Table</H4></A>The single-banded lookup table contains data 
  for a single channel or image component. To create a lookup table for a 
  single-band input image, use one of the single-band constructors. The 
  constructors take up to three parameters: 
  <P>
  <UL>
    <LI>A pointer to the data to be stored in the table. The data may be of type 
    <CODE>Byte</CODE>, <CODE>Short</CODE>, <CODE>UShort</CODE>, 
    <CODE>Int</CODE>, <CODE>Float</CODE>, or <CODE>Double</CODE>.
    <P></P></LI></UL>
  <UL>
    <LI>The offset. The offset selects the lookup table subrange. The offset 
    value is subtracted from the input value before indexing into the table 
    array.
    <P></P></LI></UL>
  <UL>
    <LI>A boolean flag that indicates whether Short data is of type Short or 
    UShort.
    <P></P></LI></UL><A 
  href="http://java.sun.com/products/java-media/jai/forDevelopers/jai1_0_1guide-unc/Image-enhance.doc.html#69572">Listing 
  7-3</A> shows an example of the construction of a single-band byte lookup 
  table.
  <P><CAPTION><FONT size=-1><B><A name=69572>
  <CENTER><FONT size=-1><B><I>Listing 7-3 </I><IMG 
  src="Image Enhancement.files/sm-blank.gif" border=0> Example Single-band 
  Lookup Table</B></FONT></CENTER></A>
  <P></B></FONT></CAPTION>
  <HR>
  <TR valign="top"><TD><PRE>     byte[] tableData = new byte[0x10000];
     for (int i = 0; i &lt; 0x10000; i++) {
     tableData[i] = (byte)(i &gt;&gt; 8);
     }
     
     // Create a LookupTableJAI object to be used with the
     // "lookup" operator.
     LookupTableJAI table = new LookupTableJAI(tableData);
</PRE>
  <HR>

  <P>
  <TABLE border=0>
    <TBODY>
    <TR>
      <TD><IMG src="Image Enhancement.files/cistine.gif"></TD>
      <TD>
        <HR>
        <B>API:</B> <CODE>javax.media.jai.LookupTableJAI </CODE>
        <HR>
      </TD></TR></TBODY></TABLE><PRE><UL>
<LI>LookupTableJAI(byte[] data)
<P></P></LI></UL></PRE>
  <DL><A name=52020>
    <DT>
    <DD>constructs a single-banded byte lookup table with an index offset of 0.
    <P>
    <TABLE cellPadding=3 border=3>
      <CAPTION><FONT size=-1><B></B></FONT></CAPTION>
      <TBODY>
      <TR vAlign=top>
        <TD><EM>Parameters</EM>: 
          <P></P>
        <TD><CODE>data</CODE> 
          <P></P>
        <TD>The single-banded byte data 
          <P></P></TR></TBODY></TABLE></A>
    <P></P></DD></DL><PRE><UL>
<LI>LookupTableJAI(byte[] data, int offset)
<P></P></LI></UL></PRE>
  <DL><A name=55653>
    <DT>
    <DD>constructs a single-banded byte lookup table with an index offset.
    <P>
    <TABLE cellPadding=3 border=3>
      <CAPTION><FONT size=-1><B></B></FONT></CAPTION>
      <TBODY>
      <TR vAlign=top>
        <TD rowSpan=2><EM>Parameters</EM>: 
          <P></P>
        <TD><CODE>data</CODE> 
          <P></P>
        <TD>The single-banded byte data 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>offset</CODE> 
          <P></P>
        <TD>The offset 
          <P></P></TR></TBODY></TABLE></A>
    <P></P></DD></DL><PRE><UL>
<LI>LookupTableJAI(short[] data, boolean isUShort)
<P></P></LI></UL></PRE>
  <DL><A name=55831>
    <DT>
    <DD>constructs a single-banded short or unsigned short lookup table with an 
    index offset of 0.
    <P>
    <TABLE cellPadding=3 border=3>
      <CAPTION><FONT size=-1><B></B></FONT></CAPTION>
      <TBODY>
      <TR vAlign=top>
        <TD rowSpan=2><EM>Parameters</EM>: 
          <P></P>
        <TD><CODE>data</CODE> 
          <P></P>
        <TD>The single-banded short data 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>isUShort</CODE> 
          <P></P>
        <TD>True if the data type is <CODE>DataBuffer.TYPE_USHORT</CODE>; 
          false if the data type is <CODE>DataBuffer.TYPE_SHORT</CODE>. 
          <P></P></TR></TBODY></TABLE></A>
    <P></P></DD></DL><PRE><UL>
<LI>LookupTableJAI(short[] data, int offset, boolean isUShort)
<P></P></LI></UL></PRE>
  <DL><A name=55893>
    <DT>
    <DD>constructs a single-banded short or unsigned short lookup table with an 
    index offset.
    <P>
    <TABLE cellPadding=3 border=3>
      <CAPTION><FONT size=-1><B></B></FONT></CAPTION>
      <TBODY>
      <TR vAlign=top>
        <TD rowSpan=3><EM>Parameters</EM>: 
          <P></P>
        <TD><CODE>data</CODE> 
          <P></P>
        <TD>The single-banded short data 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>offset</CODE> 
          <P></P>
        <TD>The offset 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>isUShort</CODE> 
          <P></P>
        <TD>True if the data type is <CODE>DataBuffer.TYPE_USHORT</CODE>; 
          false if the data type is <CODE>DataBuffer.TYPE_SHORT</CODE>. 
          <P></P></TR></TBODY></TABLE></A>
    <P></P></DD></DL><PRE><UL>
<LI>LookupTableJAI(int[] data)
<P></P></LI></UL></PRE>
  <DL><A name=56100>
    <DT>
    <DD>constructs a single-banded int lookup table with an index offset
    <P>
    <TABLE cellPadding=3 border=3>
      <CAPTION><FONT size=-1><B></B></FONT></CAPTION>
      <TBODY>
      <TR vAlign=top>
        <TD><EM>Parameters</EM>: 
          <P></P>
        <TD><CODE>data</CODE> 
          <P></P>
        <TD>The single-banded int data 
          <P></P></TR></TBODY></TABLE></A>
    <P></P></DD></DL><PRE><UL>
<LI>LookupTableJAI(int[] data, int offset)
<P></P></LI></UL></PRE>
  <DL><A name=56136>
    <DT>
    <DD>constructs a single-banded int lookup table with an index offset
    <P>
    <TABLE cellPadding=3 border=3>
      <CAPTION><FONT size=-1><B></B></FONT></CAPTION>
      <TBODY>
      <TR vAlign=top>
        <TD rowSpan=2><EM>Parameters</EM>: 
          <P></P>
        <TD><CODE>data</CODE> 
          <P></P>
        <TD>The single-banded int data 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>offset</CODE> 
          <P></P>
        <TD>The offset 
          <P></P></TR></TBODY></TABLE></A>
    <P></P></DD></DL><PRE><UL>
<LI>LookupTableJAI(float[] data)
<P></P></LI></UL></PRE>
  <DL><A name=56333>
    <DT>
    <DD>constructs a single-banded float lookup table with an index offset of 0
    <P>
    <TABLE cellPadding=3 border=3>
      <CAPTION><FONT size=-1><B></B></FONT></CAPTION>
      <TBODY>
      <TR vAlign=top>
        <TD><EM>Parameters</EM>: 
          <P></P>
        <TD><CODE>data</CODE> 
          <P></P>
        <TD>The single-banded float data 
          <P></P></TR></TBODY></TABLE></A>
    <P></P></DD></DL><PRE><UL>
<LI>LookupTableJAI(float[] data, int offset)
<P></P></LI></UL></PRE>
  <DL><A name=56373>
    <DT>
    <DD>constructs a single-banded float lookup table with an index offset
    <P>
    <TABLE cellPadding=3 border=3>
      <CAPTION><FONT size=-1><B></B></FONT></CAPTION>
      <TBODY>
      <TR vAlign=top>
        <TD rowSpan=2><EM>Parameters</EM>: 
          <P></P>
        <TD><CODE>data</CODE> 
          <P></P>
        <TD>The single-banded float data 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>offset</CODE> 
          <P></P>
        <TD>The offset 
          <P></P></TR></TBODY></TABLE></A>
    <P></P></DD></DL><PRE><UL>
<LI>LookupTableJAI(double[] data)
<P></P></LI></UL></PRE>
  <DL><A name=56522>
    <DT>
    <DD>constructs a single-banded double lookup table with an index offset of 0
    <P>
    <TABLE cellPadding=3 border=3>
      <CAPTION><FONT size=-1><B></B></FONT></CAPTION>
      <TBODY>
      <TR vAlign=top>
        <TD><EM>Parameters</EM>: 
          <P></P>
        <TD><CODE>data</CODE> 
          <P></P>
        <TD>The single-banded double data 
          <P></P></TR></TBODY></TABLE></A>
    <P></P></DD></DL><PRE><UL>
<LI>LookupTableJAI(double[] data, int offset)
<P></P></LI></UL></PRE>
  <DL><A name=56558>
    <DT>
    <DD>constructs a single-banded double lookup table with an index offset
    <P>
    <TABLE cellPadding=3 border=3>
      <CAPTION><FONT size=-1><B></B></FONT></CAPTION>
      <TBODY>
      <TR vAlign=top>
        <TD rowSpan=2><EM>Parameters</EM>: 
          <P></P>
        <TD><CODE>data</CODE> 
          <P></P>
        <TD>The single-banded double data 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>offset</CODE> 
          <P></P>
        <TD>The offset 
          <P></P></TR></TBODY></TABLE></A>
    <P></P></DD></DL><A name=56722>
  <H4>7.6.1.2 <IMG src="Image Enhancement.files/space.gif">Creating a Multi-band 
  Lookup Table</H4></A>The multi-band lookup table contains data for more than 
  one channels or image components, such as separate arrays for R, G, and B. To 
  create a lookup table for a multi-band input image, use one of the multi-band 
  constructors. Like the single-band constructors, the multi-band constructors 
  take up to three parameters: 
  <P>
  <UL>
    <LI>A pointer to the data to be stored in the table. The data may be of type 
    Byte, Short, UShort, Int, Float, or Double.
    <P></P></LI></UL>
  <UL>
    <LI>The offset. The offset selects the lookup table subrange. The offset 
    value is subtracted from the input value before indexing into the table 
    array. The constructors allow you to specify one offset for all of the bands 
    or separate offsets for each band.
    <P></P></LI></UL>
  <UL>
    <LI>A boolean flag that indicates whether Short data is of type Short or 
    UShort.
    <P></P></LI></UL><A