Package org.libjpegturbo.turbojpeg

Class TJTransformer

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable
    public class TJTransformer
extends TJDecompressor
    TurboJPEG lossless transformer

    • Constructor Detail

      • TJTransformer

        public TJTransformer()
              throws TJException
        Create a TurboJPEG lossless transformer instance.
        Throws:
        TJException

      • TJTransformer

        public TJTransformer​(byte[] jpegImage)
              throws TJException
        Create a TurboJPEG lossless transformer instance and associate the JPEG source image stored in jpegImage with the newly created instance.
        Parameters:
        jpegImage - buffer containing the JPEG source image to transform. (The size of the JPEG image is assumed to be the length of the array.) This buffer is not modified.
        Throws:
        TJException

      • TJTransformer

        public TJTransformer​(byte[] jpegImage,
                     int imageSize)
              throws TJException
        Create a TurboJPEG lossless transformer instance and associate the JPEG source image of length imageSize bytes stored in jpegImage with the newly created instance.
        Parameters:
        jpegImage - buffer containing the JPEG source image to transform. This buffer is not modified.
        imageSize - size of the JPEG source image (in bytes)
        Throws:
        TJException

    • Method Detail

      • setICCProfile

        public void setICCProfile​(byte[] iccBuf)
                   throws TJException
        Embed an ICC (International Color Consortium) color management profile in JPEG images generated by subsequent transform operations.
        Parameters:
        iccBuf - buffer containing an ICC profile. (The size of the ICC profile is assumed to be the length of the array.) A copy is made of the ICC profile, so this buffer can be reused as soon as this method returns. Setting this parameter to null removes any ICC profile that was previously associated with this transformer instance.
        Throws:
        TJException

      • bufSize

        public int bufSize​(TJTransform transform)
            throws TJException
        Returns the maximum size of the buffer (in bytes) required to hold a JPEG image transformed, with the given transform parameters and/or cropping region, from the JPEG source image associated with this transformer instance. This function is a wrapper for TJ.bufSize() that takes into account cropping, transposition of the width and height (which affects the destination image dimensions and level of chrominance subsampling), grayscale conversion, and the ICC profile (if any) that was previously associated with this transformer instance (see setICCProfile()) or extracted from the source image (see TJDecompressor.getICCProfile() and TJ.PARAM_SAVEMARKERS.)
        Parameters:
        transform - a TJTransform instance that specifies the transform parameters and/or cropping region for the transformed JPEG image.
        Returns:
        the maximum size of the buffer (in bytes) required to hold a JPEG image transformed, with the given transform parameters and/or cropping region, from the JPEG source image associated with this transformer instance
        Throws:
        TJException

      • transform

        public void transform​(byte[][] dstBufs,
                      TJTransform[] transforms)
               throws TJException
        Losslessly transform the JPEG source image associated with this transformer instance into one or more JPEG images stored in the given destination buffers. Lossless transforms work by moving the raw coefficients from one JPEG image structure to another without altering the values of the coefficients. While this is typically faster than decompressing the image, transforming it, and re-compressing it, lossless transforms are not free. Each lossless transform requires reading and performing Huffman decoding on all of the coefficients in the source image, regardless of the size of the destination image. Thus, this method provides a means of generating multiple transformed images from the same source or of applying multiple transformations simultaneously, in order to eliminate the need to read the source coefficients multiple times.
        Parameters:
        dstBufs - an array of JPEG destination buffers. dstbufs[i] will receive a JPEG image that has been transformed using the parameters in transforms[i]. Use bufSize() to determine the maximum size for each buffer.
        transforms - an array of TJTransform instances, each of which specifies the transform parameters and/or cropping region for the corresponding transformed JPEG image
        Throws:
        TJException

      • transform

        public TJDecompressor[] transform​(TJTransform[] transforms)
                           throws TJException
        Losslessly transform the JPEG source image associated with this transformer instance and return an array of TJDecompressor instances, each of which has a transformed JPEG image associated with it.
        Parameters:
        transforms - an array of TJTransform instances, each of which specifies the transform parameters and/or cropping region for the corresponding transformed JPEG image
        Returns:
        an array of TJDecompressor instances, each of which has a transformed JPEG image associated with it.
        Throws:
        TJException

      • getTransformedSizes

        public int[] getTransformedSizes()
        Returns an array containing the sizes of the transformed JPEG images (in bytes) generated by the most recent transform operation.
        Returns:
        an array containing the sizes of the transformed JPEG images (in bytes) generated by the most recent transform operation.