Image (bitmap) data values may be expressed as absolute value-only, or as positive/negative integer values ("signed" images). These image values are stored in a look-up table (LUT), where the image data range is represented as a single series of (positive) integer values.
Most LEADTOOLS image functions now support both signed (+/– integer) and unsigned images. Where signed images are supported, LEADTOOLS can manipulate either the LUT values, or the image data directly. When displaying images, mapping the negative and positive values of the signed images to LUT values speeds up processing.
Who uses signed images?
Signed images are most commonly used by medical imaging applications supporting the DICOM standard. Astronomical and geophysical image data may also be signed.
When and why do signed image values matter?
Signed image data is often used when image classification is based on variation from a reference value. For example, image values for DICOM images acquired from a Modality depend on a reference plate, with some (positive) values recorded above the plate threshold, and some (negative) below. Some astronomical images are also signed as variations from a nominal background reference value.
When would I want to manipulate the LUT, and when would I want to manipulate the image data directly?
For many effects, the final result will be the same whether you apply the effect on the LUT or the source data—but processing the LUT will be much faster. For example, inverting the start and end colors of the LUT is faster than inverting the intensity value of each pixel.
Other LEADTOOLS SDK Technologies Related to Document Image Processing
LEADTOOLS SDK Products that Include Document Image Processing
Hover over each product for a description. Click for more details.
LEADTOOLS Vector Imaging Pro is a full featured raster and vector imaging SDK that supports load, save, decompression and compression of over 150 image formats via C DLL, C++ classes, .NET classes, and WIC codecs. Extended grayscale and color support such as 12 and 16 bit grayscale data and 48 and 64 bit color data is included only in LEADTOOLS Document Imaging, Recognition Imaging, Document Imaging Suite, Medical Imaging, PACS Imaging, and Medical Imaging Suite SDKs.
The LEADTOOLS Document Imaging SDK is a comprehensive document imaging SDK. Some of the features included are image annotation, memory optimizations for bitonal image data and enhanced display of black and white images. Additionally, LEADTOOLS Document Imaging supports the load, save, decompression and compression of over 150 image formats via C DLL, C++ classes, .NET classes, WIC codecs, WF activities and WCF services. Also includes extended grayscale and color support such as 12 and 16 bit grayscale data and 48 and 64 bit color data.
The LEADTOOLS Recognition Imaging SDK includes everything a developer needs to create solutions to OCR document images and process form images. Some of the features included are OCR with text searchable PDF output, MICR, forms recognition and processing, image processing to improve recognition performance, and full barcode support.
The LEADTOOLS Document Imaging Suite SDK is the most comprehensive document imaging SDK available. Some of the features included are OCR with text searchable PDF output, MICR, forms recognition and processing, image processing to improve recognition performance, full barcode support, EMF to document format conversion, printer output capture and comprehensive PDF support.
The LEADTOOLS Medical Imaging SDK includes complete DICOM dataset support as well as medical image viewing functionality. LEADTOOLS Medical Imaging is a full featured raster, document and medical imaging SDK that supports load, save, decompression and compression of over 150 image formats via C DLL, C++ classes, .NET classes, WIC codecs, WF activities and WCF services. Also includes extended grayscale and color support such as 12 and 16 bit grayscale data and 48 and 64 bit color data.
LEADTOOLS PACS Imaging is a full featured PACS, raster, document, medical imaging SDK that includes functions to implement a complete PACS client and server solution as well as medical imaging functionality. LEADTOOLS PACS Imaging SDK supports the load, save, decompression and compression of over 150 image formats via C DLL, C++ classes, .NET classes, WIC codecs, WF activities and WCF services. Also includes extended grayscale and color support such as 12 and 16 bit grayscale data and 48 and 64 bit color data.
LEADTOOLS Medical Imaging Suite is a full featured PACS, raster, document, and medical imaging SDK that includes functions to implement a complete PACS client and server solution as well as medical imaging, medical 3D, and multimedia functionality. LEADTOOLS Medical Imaging Suite SDK supports the load, save, decompression and compression of over 150 image formats via C DLL, C++ classes, .NET classes, WIC codecs, WF activities and WCF services. Also includes extended grayscale and color support such as 12 and 16 bit grayscale data and 48 and 64 bit color data.
|
