Java Interpolation.INTERP_BILINEAR属性代码示例

protected static byte interpolationToByte(
		final Interpolation interpolation ) {
	// this is silly because it seems like a translation JAI should provide,
	// but it seems its not provided and its the most efficient approach
	// (rather than serializing class names)
	if (interpolation instanceof InterpolationNearest) {
		return Interpolation.INTERP_NEAREST;
	}
	if (interpolation instanceof InterpolationBilinear) {
		return Interpolation.INTERP_BILINEAR;
	}
	if (interpolation instanceof InterpolationBicubic2) {
		return Interpolation.INTERP_BICUBIC_2;
	}

	return Interpolation.INTERP_BICUBIC;
}
 

private int getResampleType() {
    final int resamplingType;
    if ("Nearest".equalsIgnoreCase(resamplingName)) {
        resamplingType = Interpolation.INTERP_NEAREST;
    } else if ("Bilinear".equalsIgnoreCase(resamplingName)) {
        resamplingType = Interpolation.INTERP_BILINEAR;
    } else if ("Bicubic".equalsIgnoreCase(resamplingName)) {
        resamplingType = Interpolation.INTERP_BICUBIC;
    } else {
        resamplingType = -1;
    }
    return resamplingType;
}
 

private static int getInterpolationType(String interpolationString) {
    final int interpolationType;
    if ("Nearest".equalsIgnoreCase(interpolationString)) {
        interpolationType = Interpolation.INTERP_NEAREST;
    } else if ("Bilinear".equalsIgnoreCase(interpolationString)) {
        interpolationType = Interpolation.INTERP_BILINEAR;
    } else if ("Bicubic".equalsIgnoreCase(interpolationString)) {
        interpolationType = Interpolation.INTERP_BICUBIC;
    } else {
        interpolationType = -1;
    }
    return interpolationType;
}
 

/** <p> <code>combineFilters</code> based on <code>resampleType</code> and
    * input partial <code>qsFilter</code> (see above for details on qsFilter format).
    * Input <code>qsFilter</code> is restricted to have odd parity
    * (<code>qsFilter[0]</code> is at the center of the kernel).
    *
    * @param scaleFactor positive int representing the downsample factor.
    * @param resampleType int representing the interpolation type.
    * @param qsFilter floating partial kernel array (antialias filter).
    * @return floating partial kernel representing combined resample and qsFilter.
    */
   private static float [] combineFilters(int scaleFactor,
                                          int resampleType,
				   float [] qsFilter) {

       // Odd scale factors imply no resample filter is required
       // return pointer to the qsFilter
       if ((scaleFactor%2) == 1) return (float [])qsFilter.clone();

       int qsParity = 1;
int resampParity = 0; // Unless nearest neighbor case is selected (ignored)

       switch (resampleType) {
   case Interpolation.INTERP_NEAREST: // Return a copy of the qsFilter
              return (float [])qsFilter.clone();
   case Interpolation.INTERP_BILINEAR: // 2 by 2 resample filter
              float [] bilinearKernel = { 1.0F/2.0F };
       return convolveSymmetricKernels(
           qsParity, resampParity, qsFilter, bilinearKernel);
   case Interpolation.INTERP_BICUBIC: // 4 by 4 resample filter
              float [] bicubicKernel = { 9.0F/16.0F, -1.0F/16.0F };
              return convolveSymmetricKernels(
           qsParity, resampParity, qsFilter, bicubicKernel);
   case Interpolation.INTERP_BICUBIC_2: // alternate 4 by 4 resample filter
              float [] bicubic2Kernel = { 5.0F/8.0F, -1.0F/8.0F };
              return convolveSymmetricKernels(
           qsParity, resampParity, qsFilter, bicubic2Kernel);
          default:
     throw new IllegalArgumentException(
         JaiI18N.getString("FilteredSubsample0"));
}


   }
 

/** <p> <code>FilteredSubsampleOpImage</code> constructs an OpImage representing
    * filtered integral subsampling.  The scale factors represent the ratio of
    * source to destination dimensions.
    *
    * @param source a RenderedImage.
    * @param extender a BorderExtender, or null.
    * @param config a Map object possibly holding tile cache information
    * @param layout an ImageLayout optionally containing the tile grid layout,
    *	  SampleModel, and ColorModel, or null.
    * @param interp a Interpolation object to use for resampling.
    * @param scaleX downsample factor along x axis.
    * @param scaleY downsample factor along y axis.
    * @param qsFilter symmetric filter coefficients (partial kernel).
    * @throws IllegalArgumentException if the interp type is not one of:
    *    INTERP_NEAREST, INTERP_BILINEAR, INTERP_BICUBIC, or INTERP_BICUBIC_2
    */
   public FilteredSubsampleOpImage(RenderedImage source,
   				    BorderExtender extender,
			    Map config,
			    ImageLayout layout,
                                   int scaleX,
			    int scaleY,
			    float [] qsFilter,
			    Interpolation interp) {

       // Propagate to GeometricOpImage constructor
       super(vectorize(source),
             layoutHelper(source, interp, scaleX, scaleY, qsFilter.length, layout),
             config,   // Map object
             true,     // cobbleSources,
      extender, // extender
             interp,    // Interpolation object
      null);

       int resampleType;

       // Determine the interpolation type, if not supported throw exception
if (interp instanceof InterpolationNearest) {
    resampleType = Interpolation.INTERP_NEAREST;
} else if (interp instanceof InterpolationBilinear) {
           resampleType = Interpolation.INTERP_BILINEAR;
} else if (interp instanceof InterpolationBicubic) {
           resampleType = Interpolation.INTERP_BICUBIC;
} else if (interp instanceof InterpolationBicubic2) {
           resampleType = Interpolation.INTERP_BICUBIC_2;
       } else {
           throw new IllegalArgumentException(
        JaiI18N.getString("FilteredSubsample3"));
}

       // Construct combined anti-alias and resample kernels.
       this.hParity = filterParity(scaleX,resampleType);
this.vParity = filterParity(scaleY,resampleType);
this.hKernel = combineFilters(scaleX,resampleType,qsFilter);
       this.vKernel = combineFilters(scaleY,resampleType,qsFilter);

this.scaleX = scaleX;
this.scaleY = scaleY;


   }