org.libjpegturbo.turbojpeg
Interface TJCustomFilter

public interface TJCustomFilter

Custom filter callback interface

Method Summary

void

customFilter(java.nio.ShortBuffer coeffBuffer, java.awt.Rectangle bufferRegion, java.awt.Rectangle planeRegion, int componentID, int transformID, TJTransform transform) A callback function that can be used to modify the DCT coefficients after they are losslessly transformed but before they are transcoded to a new JPEG file.

Method Detail

customFilter

void customFilter(java.nio.ShortBuffer coeffBuffer,
                  java.awt.Rectangle bufferRegion,
                  java.awt.Rectangle planeRegion,
                  int componentID,
                  int transformID,
                  TJTransform transform)
                  throws java.lang.Exception

A callback function that can be used to modify the DCT coefficients after they are losslessly transformed but before they are transcoded to a new JPEG file. This allows for custom filters or other transformations to be applied in the frequency domain.

Parameters:

coeffBuffer - a buffer containing transformed DCT coefficients. (NOTE: this buffer is not guaranteed to be valid once the callback returns, so applications wishing to hand off the DCT coefficients to another function or library should make a copy of them within the body of the callback.)

bufferRegion - rectangle containing the width and height of coeffBuffer as well as its offset relative to the component plane. TurboJPEG implementations may choose to split each component plane into multiple DCT coefficient buffers and call the callback function once for each buffer.

planeRegion - rectangle containing the width and height of the component plane to which coeffBuffer belongs

componentID - ID number of the component plane to which coeffBufferbelongs (Y, Cb, and Cr have, respectively, ID's of 0, 1, and 2 in typical JPEG images.)

transformID - ID number of the transformed image to which coeffBuffer belongs. This is the same as the index of the transform in the transforms array that was passed to TJTransformer.transform().

transform - a TJTransform instance that specifies the parameters and/or cropping region for this transform

Throws:

java.lang.Exception