FeatureType

Intensity features represent the average brightness of each cell, normalized from 0 (black) to 1 (white). This is the most commonly used feature type for document classification, as it captures the overall layout and presence of content in each region.

• Use for most structured documents, such as forms, invoices, and letters.
• Provides a simple, robust basis for distinguishing between document types with different layouts.
• Fast to compute and hardware-accelerated.

GradientAngle features capture the dominant edge direction within each cell, indicating the orientation of lines, text, or graphical elements.

• Useful for distinguishing documents with different line or text orientations.
• Most effective on grayscale or color images, especially photographs or documents with significant graphical content.
• May not add value for simple black-and-white forms.

COG_Angle features measure the direction from the center of each cell to the center of gravity (COG) of dark pixels within the cell. This captures the spatial distribution of content, such as the alignment of text or graphics.

• Combine with 'Intensity' for improved accuracy on forms with graphical elements, stamps, or logos.
• Helps distinguish between document types with similar layouts but different content positioning.

COG_Magnitude features measure the normalized distance from the center of each cell to the center of gravity of dark pixels. This quantifies how far content is offset from the cell center.

• Useful for detecting the presence and spread of content within each cell.
• Can help differentiate between filled and empty regions, or between different types of marks.

Entropy features represent the local complexity or "busyness" of each cell, based on edge and gradient information. High entropy indicates more variation, such as handwriting, stamps, or background noise.

• Use to distinguish between blank, simple, and complex regions.
• Helpful for detecting signatures, stamps, or noisy backgrounds.
• May increase feature vector size and processing time.

ColorSpaceChannel features compute the average value of a selected color channel (e.g., Red, Green, Blue, Hue, Saturation, Value) for each cell.

• Use when color information is important for classification, such as distinguishing between highlighted, stamped, or color-coded documents.
• Requires configuration of the 'Color Space' and 'Channel' properties.
• May not be relevant for black-and-white or grayscale documents.