Implementing JPEG 2000 Plug in Features

JPEG 2000 is a wavelet based compression stored in a hierarchical format which contains several stored resolutions of the image in the same file without duplication. For that reason, a JPEG 2000 compressed image can then be sent to a device in the resolution that best fits, without additional storage overhead.

The LEADTOOLS JPEG 2000 Plug in provides support for loading and saving the JPEG 2000 file formats. The JPEG 2000 file formats provide greater flexibility and better image quality, especially at higher compression, than standard JPEG. The greater flexibility includes the ability to control:

$image\sqrblit.gif$ whether or not to transform RGB images to YUV prior to compression

$image\sqrblit.gif$ the type of quantization to use when determining the quantization step size

$image\sqrblit.gif$ the amount of compression

$image\sqrblit.gif$ the size and location of tiles

$image\sqrblit.gif$ the number of resolution levels in the file

$image\sqrblit.gif$ the progression order

$image\sqrblit.gif$ the code block height and width

$image\sqrblit.gif$ whether to use markers to help detect corruption during transmission

$image\sqrblit.gif$ etc.

LEADTOOLS provides a FILEJ2KOPTIONS structure for controlling the JPEG 2000 features listed above. To determine the current settings for the JPEG 2000 features, use the L_GetJ2KOptions function. To change the JPEG 2000 features, use the L_SetJ2KOptions function.

To load JPEG 2000 images progressively, set the nPasses member of the LOADFILEOPTIONS structure, just as you would for regular JPEG files.

To get the default settings for the JPEG 2000 features, use the L_GetDefaultJ2KOptions function.

This support is available only in the LEADTOOLS JPEG 2000 Plug in, and must be unlocked. For more information on unlocking this support, refer to JPEG 2000 Plug In Support Instructions.