Class RectROIMaskGenerator

java.lang.Object
jj2000.j2k.roi.encoder.ROIMaskGenerator
jj2000.j2k.roi.encoder.RectROIMaskGenerator

public class RectROIMaskGenerator extends ROIMaskGenerator
This class generates the ROI masks when there are only rectangular ROIs in the image. The ROI mask generation can then be simplified by only calculating the boundaries of the ROI mask in the particular subbands

The values are calculated from the scaling factors of the ROIs. The values with which to scale are equal to u-umin where umin is the lowest scaling factor within the block. The umin value is sent to the entropy coder to be used for scaling the distortion values.

To generate and to store the boundaries of the ROIs, the class SubbandRectROIMask is used. There is one tree of SubbandMasks for each component.

See Also:
  • Constructor Details

    • RectROIMaskGenerator

      public RectROIMaskGenerator(ROI[] ROIs, int nrc)
      The constructor of the mask generator. The constructor is called with the ROI data. This data is stored in arrays that are used to generate the SubbandRectROIMask trees for each component.
      Parameters:
      ROIs - The ROI info.
      nrc - number of components.
  • Method Details

    • getROIMask

      public boolean getROIMask(DataBlkInt db, Subband sb, int magbits, int c)
      This functions gets a DataBlk the size of the current code-block and fills this block with the ROI mask.

      In order to get the mask for a particular Subband, the subband tree is traversed and at each decomposition, the ROI masks are computed. The roi bondaries for each subband are stored in the SubbandRectROIMask tree.

      Specified by:
      getROIMask in class ROIMaskGenerator
      Parameters:
      db - The data block that is to be filled with the mask
      sb - The root of the subband tree to which db belongs
      magbits - The max number of magnitude bits in any code-block
      c - The component for which to get the mask
      Returns:
      Whether or not a mask was needed for this tile
    • toString

      public String toString()
      This function returns the relevant data of the mask generator
      Overrides:
      toString in class Object
    • makeMask

      public void makeMask(Subband sb, int magbits, int n)
      This function generates the ROI mask for the entire tile. The mask is generated for one component. This method is called once for each tile and component.
      Specified by:
      makeMask in class ROIMaskGenerator
      Parameters:
      sb - The root of the subband tree used in the decomposition
      n - component number
      magbits - The max number of magnitude bits in any code-block