LuraWave Plug-InControl Settings Reference

For all Windows 32-Bit Platforms

Table of Contents

LuraWave Plug-In Control Settings Reference . . . . . . . 1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Supported Save Compressions . . . . . . . . . . . . . . . . . . . . . . . . . . 2Progressive compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2Baseline Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2Save Compressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Image Control Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Control Settings Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3IG_CONTROL_LURAWAVE_QUALITY . . . . . . . . . . . . . . . . . . . . . .3IG_CONTROL_LURAWAVE_SCAN_MODE . . . . . . . . . . . . . . . . . . .3

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

i • ImageGear PDF Table of Contents

Table of Contents ImageGear PDF • ii

LuraWave Plug-InControl Settings Reference

OverviewLuraTech’s flagship product, LuraWave, provides a revolutionary, platform-independent, wavelet-based compression format (.lwf). LuraWave’s analyzing wavelet filter allows a lossless compression at low compression ratios and lossy compression at higher ratios. LuraWave’s lossless image compression significantly outperforms that of comparable techniques, like LZW and TIFF.

Compared to conventional compression methods like JPEG, LuraWave maintains maximum, user-defined image quality using a lossless-to-lossy compression scheme. LuraWave has 5:1 lossless (guaranteed pixel identity) compression and 1:100 lossy compression without any apparent artifacts. But users can select compression ratios up to 1:200.

Images in standard digital formats (for example, TIFF, BMP, PPM, JPEG) can be easily converted to the LuraWave format through:

• LuraWave plug-ins, available online for applications like Adobe Photoshop, Jasc Paintshop Pro, Netscape and Microsoft browsers, Cumulus, and Macromedia Director.

• Standalone solutions, like LuraWave SmartCompress, which can compress images to less than 0.5 percent of their original size, facilitating the sharing of high-quality images quickly and easily through e-mail or personal Web sites. The desired image size is specified by the user, making SmartCompress extremely valuable to users with limited bandwidths or storage.

• Software development kits (C-SDK, OCX-SDK).

LuraWave allows you to use a wide variety of new, wavelet-based, compression techniques. Advantages include:

• Fast compression and decompression. LuraWave compression is an extremely fast wavelet-based image compression technique. Compression and decompression consume about the same computation time.

• Excellent image quality at high compression rates.

• A choice of lossless or lossy image compression.

• A user-specified compression rate. Size-dependent compression control is embedded in LuraWave, while other compression techniques dictate file size by the content of the image and can vary from that of the user’s desired file size. Of course, LuraWave also grants you the option to compress an image by setting the desired quality, rather than file size.

• Elimination of JPEG-like blocking artifacts. JPEG uses the inherently lossy Discrete Cosine Transform compression algorithm, which compresses an image in partitioned “tiles.” LuraWave uses a special Discrete Wavelet Transform image analyzing method that results in improved image quality by performing Discrete Wavelet analysis over the whole image without tile partitioning, so there are no residual “blocking” artifacts.

• Quicklook generation and scale image reconstruction based on embedded coding techniques.

Overview ImageGear PDF • 1

• Scaled image reconstruction means the whole image can be reconstructed by only small fractions of the compressed data source. That is, by 1 percent, 10 percent, 50 percent and so on (the quality of the reconstructed image being proportionate to the amount of available data).

The name of the ImageGear LuraWave plug-in is IGLura.dll. For information on using the newly available ImageGear plug-ins in your application, see the “ImageGear Plug-Ins” section in Chapter One of the main ImageGear manual.

Supported Save CompressionsThe LuraWave codec has two compression modes, progressive and baseline.

Progressive compressionIn the progressive or embedded mode of the codec, the whole image is compressed at once. Then, image data is ordered hierarchically, with information describing the most important image features (sharp edges, large areas) is near the head of the file; less important information is near the end. This makes it possible to preserve the most important file information, even if the file is arbitrarily cut off. During transmission over a slow network connection, a rough version of the image can be reconstructed before the transmission is even completed. As a result, this mode is especially suitable for pictures in networks (like the Internet). However, only relatively small pictures should be compressed in this mode (up to 1000 by 1000 pixels, depending on the computer’s memory configuration) because the full image is held in memory during encoding.

Baseline CompressionVery large images should be compressed in the baseline mode. In this mode, stripes consisting of several pixel rows are compressed sequentially. Only one stripe is held in the memory at a time, so less memory is used. The hierarchical structure of the compressed image file is partially lost. A section in the compressed file contains the hierarchically ordered information of only one stripe.

Save CompressionsTo save an image with LuraWave compression, assign a defined Save constant to the lFormatType parameter of IG_save_file (DLL), or to the SaveFormat property (ActiveX). These constants are defined in your gear.h (DLL) and gear.bas (ActiveX) files.

To Save As: Use:

8g, 16g, 24 bpp images using the LuraWave compression method

IG_SAVE_LURAWAVE

2 • ImageGear PDF Supported Save Compressions

Image Control Options

Control Settings Reference

Data Type: DOUBLE

Purpose:

This control option sets compression coefficient. If zero, lossless compression method will be used. For example, if you set 2 for this control option then size of the output file will be less by half then size of the original uncompressed image

Valid Values: Any non-negative value.

Default Value: 10.0

DLL Example:

DOUBLE dWltQuality=40.0;IG_image_control_set (IG_CONTROL_LURAWAVE_QUALITY, (LPVOID)&dWltQuality);

ActiveX Example:

Gear1.ImageControlSet IG_CONTROL_LURAWAVE_QUALITY, 40.0

Data Type: INT

Control Option Value Description

IG_CONTROL_LURAWAVE_ QUALITY

Any non-negative value Compression coefficient. If zero, lossless compression method will be used

IG_CONTROL_LURAWAVE_ SCAN_MODE

IG_LW_SMODE_ BASELINEIG_LW_SMODE_ EMBEDDED

Compression mode

IG_CONTROL_LURAWAVE_QUALITY

IG_CONTROL_LURAWAVE_SCAN_MODE

Image Control Options ImageGear PDF • 3

Purpose:

This control option sets compression mode.

Valid Values:

IG_LW_SMODE_BASELINEIG_LW_SMODE_EMBEDDED

Default Value: IG_LW_SMODE_EMBEDDED

DLL Example:

IG_image_control_set (IG_CONTROL_LURAWAVE_SCAN_MODE, (LPVOID) IG_LW_SMODE_BASELINE);

ActiveX Example:

Gear1.ImageControlSet IG_CONTROL_LURAWAVE_SCAN_MODE, IG_LW_SMODE_BASELINE

4 • ImageGear PDF Control Settings Reference

Index ImageGear PDF • 5

Index

BBaseline compression 2

CControl Options 3Control Settings 3

IIG_CONTROL_LURAWAVE_QUALITY 3IG_CONTROL_LURAWAVE_SCAN_MODE 3Image Control Options 3

OOverview 1

PProgressive compression 2

Qquality (setting) 3

SSave Compressions 2Save compressions 2scan mode 3Settings Reference 3