image acquisition and display.htm

是一部关于java高级图像处理的的一本入门书

  method. A shortcut is to call the <CODE>setData()</CODE> method, which copies 
  a rectangular region from a supplied <CODE>Raster</CODE> directly into the 
  <CODE>TiledImage</CODE>. 
  <P>A final way to modify the contents of a <CODE>TiledImage</CODE> is through 
  calls to the <CODE>createGraphics()</CODE> method. This method returns a 
  <CODE>GraphicsJAI</CODE> object that can be used to draw line art, text, and 
  images in the usual AWT manner. 
  <P>A <CODE>TiledImage</CODE> does not attempt to maintain synchronous state on 
  its own. That task is left to <CODE>SnapshotImage</CODE>. If a synchronous 
  (unchangeable) view of a <CODE>TiledImage</CODE> is desired, its 
  <CODE>createSnapshot()</CODE> method must be used. Otherwise, changes due to 
  calls to <CODE>set()</CODE> or direct writing of tiles by objects that call 
  <CODE>getWritableTile()</CODE> will be visible. 
  <P><CODE>TiledImage</CODE> does not actually cause its tiles to be computed 
  until their contents are demanded. Once a tile has been computed, its contents 
  may be discarded if it can be determined that it can be recomputed identically 
  from the source. The <CODE>lockTile()</CODE> method forces a tile to be 
  computed and maintained for the lifetime of the <CODE>TiledImage</CODE>. 
  <P>
  <TABLE border=0>
    <TBODY>
    <TR>
      <TD><IMG src="Image Acquisition and Display.files/cistine.gif"></TD>
      <TD>
        <HR>
        <B>API:</B> <CODE>javax.media.jai.TiledImage </CODE>
        <HR>
      </TD></TR></TBODY></TABLE><PRE><UL>
<LI>TiledImage(Point origin, SampleModel sampleModel, 
int  tileWidth, int tileHeight)
<P></P></LI></UL></PRE>
  <DL><A name=52409>
    <DT>
    <DD>constructs a <CODE>TiledImage</CODE> with a <CODE>SampleModel</CODE> 
    that is compatible with a given <CODE>SampleModel</CODE>, and given tile 
    dimensions. The width and height are taken from the 
    <CODE>SampleModel</CODE>, and the image begins at a specified point.
    <P>
    <TABLE cellPadding=3 border=3>
      <CAPTION><FONT size=-1><B></B></FONT></CAPTION>
      <TBODY>
      <TR vAlign=top>
        <TD rowSpan=4><EM>Parameters</EM>: 
          <P></P>
        <TD><CODE>origin</CODE> 
          <P></P>
        <TD>A Point indicating the image's upper left corner. 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>sampleModel</CODE> 
          <P></P>
        <TD>A SampleModel with which to be compatible. 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>tileWidth</CODE> 
          <P></P>
        <TD>The desired tile width. 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>tileHeight</CODE> 
          <P></P>
        <TD>The desired tile height. 
          <P></P></TR></TBODY></TABLE>
    <P></A>
    <P></P></DD></DL><PRE><UL>
<LI>TiledImage(SampleModel sampleModel, int tileWidth, 
int  tileHeight)
<P></P></LI></UL></PRE>
  <DL><A name=52524>
    <DT>
    <DD>constructs a <CODE>TiledImage</CODE> starting at the global coordinate 
    origin.
    <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>sampleModel</CODE> 
          <P></P>
        <TD>A <CODE>SampleModel</CODE> with which to be compatible. 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>tileWidth</CODE> 
          <P></P>
        <TD>The desired tile width. 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>tileHeight</CODE> 
          <P></P>
        <TD>The desired tile height. 
          <P></P></TR></TBODY></TABLE>
    <P></A>
    <P></P></DD></DL><PRE><UL>
<LI>TiledImage(int minX, int minY, int width, int height, 
int  tileGridXOffset, int tileGridYOffset, 
SampleModel  sampleModel, ColorModel colorModel)
<P></P></LI></UL></PRE>
  <DL><A name=54010>
    <DT>
    <DD>constructs a <CODE>TiledImage</CODE> of a specified width and height.
    <P>
    <TABLE cellPadding=3 border=3>
      <CAPTION><FONT size=-1><B></B></FONT></CAPTION>
      <TBODY>
      <TR vAlign=top>
        <TD rowSpan=8><EM>Parameters</EM>: 
          <P></P>
        <TD><CODE>minX</CODE> 
          <P></P>
        <TD>The index of the leftmost column of tiles. 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>minY</CODE> 
          <P></P>
        <TD>The index of the uppermost row of tiles. 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>width</CODE> 
          <P></P>
        <TD>The width of the <CODE>TiledImage</CODE>. 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>height</CODE> 
          <P></P>
        <TD>The height of the <CODE>TiledImage</CODE>. 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>tileGridX-Offset</CODE> 
          <P></P>
        <TD>The <EM>x</EM> coordinate of the upper-left pixel of tile (0, 0). 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>tileGridY-Offset</CODE> 
          <P></P>
        <TD>The <EM>y</EM> coordinate of the upper-left pixel of tile (0, 0). 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>sampleModel</CODE> 
          <P></P>
        <TD>a <CODE>SampleModel</CODE> with which to be compatible. 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>colorModel</CODE> 
          <P></P>
        <TD>A <CODE>ColorModel</CODE> to associate with the image. 
          <P></P></TR></TBODY></TABLE>
    <P></A>
    <P></P></DD></DL><PRE><UL>
<LI>void setData(Raster r)
<P></P></LI></UL></PRE>
  <DL><A name=77626>
    <DT>
    <DD>sets a region of a <CODE>TiledImage</CODE> to be a copy of a supplied 
    <CODE>Raster</CODE>. The <CODE>Raster</CODE>'s coordinate system is used to 
    position it within the image. The computation of all overlapping tiles will 
    be forced prior to modification of the data of the affected area.
    <P>
    <TABLE cellPadding=3 border=3>
      <CAPTION><FONT size=-1><B></B></FONT></CAPTION>
      <TBODY>
      <TR vAlign=top>
        <TD><EM>Parameter</EM>:<EM></EM> 
          <P></P>
        <TD><CODE>r</CODE> 
          <P></P>
        <TD>A <CODE>Raster</CODE> containing pixels to be copied into the 
          <CODE>TiledImage</CODE>. 
          <P></P></TR></TBODY></TABLE>
    <P></A>
    <P></P></DD></DL><PRE><UL>
<LI>void setData(Raster r, ROI roi)
<P></P></LI></UL></PRE>
  <DL><A name=77688>
    <DT>
    <DD>sets a region of a <CODE>TiledImage</CODE> to be a copy of a supplied 
    <CODE>Raster</CODE>. The <CODE>Raster</CODE>'s coordinate system is used to 
    position it within the image. The computation of all overlapping tiles will 
    be forced prior to modification of the data of the affected area. </A>
    <P></P></DD></DL><PRE><UL>
<LI>WritableRaster getWritableTile(int tileX, int tileY)
<P></P></LI></UL></PRE>
  <DL><A name=52639>
    <DT>
    <DD>retrieves a particular tile from the image for reading and writing. The 
    tile will be computed if it hasn't been previously. Writes to the tile will 
    become visible to readers of this image in the normal Java manner.
    <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>tileX</CODE> 
          <P></P>
        <TD>The <EM>x</EM> index of the tile. 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>tileY</CODE> 
          <P></P>
        <TD>The <EM>y</EM> index of the tile. 
          <P></P></TR></TBODY></TABLE>
    <P></A>
    <P></P></DD></DL><PRE><UL>
<LI>Raster getTile(int tileX, int tileY)
<P></P></LI></UL></PRE>
  <DL><A name=52691>
    <DT>
    <DD>retrieves a particular tile from the image for reading only. The tile 
    will be computed if it hasn't been previously. Any attempt to write to the 
    tile will produce undefined results. 
    <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>tileX</CODE> 
          <P></P>
        <TD>The <EM>x</EM> index of the tile. 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>tileY</CODE> 
          <P></P>
        <TD>The <EM>y</EM> index of the tile. 
          <P></P></TR></TBODY></TABLE>
    <P></A>
    <P></P></DD></DL><PRE><UL>
<LI>boolean isTileWritable(int tileX, int tileY)
<P></P></LI></UL></PRE>
  <DL><A name=52792>
    <DT>
    <DD>returns true if a tile has writers. 
    <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>tileX</CODE> 
          <P></P>
        <TD>The <EM>x</EM> index of the tile. 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>tileY</CODE> 
          <P></P>
        <TD>The <EM>y</EM> index of the tile. 
          <P></P></TR></TBODY></TABLE>
    <P></A>
    <P></P></DD></DL><PRE><UL>
<LI>boolean hasTileWriters()
<P></P></LI></UL></PRE>
  <DL><A name=52825>
    <DT>
    <DD>returns true if any tile is being held by a writer, false otherwise. 
    This provides a quick way to check whether it is necessary to make copies of 
    tiles - if there are no writers, it is safe to use the tiles directly, while 
    registering to learn of future writers. </A>
    <P></P></DD></DL><PRE><UL>
<LI>void releaseWritableTile(int tileX, int tileY)
<P></P></LI></UL></PRE>
  <DL><A name=52849>
    <DT>
    <DD>indicates that a writer is done updating a tile. The effects of 
    attempting to release a tile that has not been grabbed, or releasing a tile 
    more than once are undefined.
    <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>tileX</CODE> 
          <P></P>
        <TD>The <EM>x</EM> index of the tile. 
          <P></P>
      <TR vAlign=top>
        <TD><CODE>tileY</CODE> 
          <P></P>
        <TD>The <EM>y</EM> index of the tile. 
          <P></P></TR></TBODY></TABLE>
    <P></A>
    <P></P></DD></DL><PRE><UL>
<LI>void set(RenderedImage im)
<P></P></LI></UL></PRE>
  <DL><A name=59584>
    <DT>
    <DD>overlays a given <CODE>RenderedImage</CODE> on top of the current 
    contents of the <CODE>TiledImage</CODE>. The source image must have a 
    <CODE>SampleModel</CODE> compatible with that of this image.
    <P>
    <TABLE cellPadding=3 border=3>