Use of colour for hand-filled form analysis and recognition

Abstract

Colour information in form analysis is currently under utilised. As technology has advanced and computing costs have reduced, the processing of forms in colour has now become practicable. This paper describes a novel colour-based approach to the extraction of filled data from colour form images.Images are first quantised to reduce the colour complexity and data is extracted by examining the colour characteristics of the images. The improved performance of the proposed method has been verified by comparing the processing time, recognition rate, extraction precision and recall rate to that of an equivalent black and white system.

Separation of overlapped color planes for document images

“…A lot of methods have been proposed to help reduce the color number of a document, and they can be divided into two categories: adaptive color reduction [4,5,8] and non-adaptive color reduction [1,2,6]. Unlike pictures, documents contain relatively few colors.…”

“…Wong et al [1] use eight predefined colors for form images and quantise each pixel into one of the eight categories. Sherkat et al [2] classify a pixel into one of the eight classes by comparing its RGB values. Li et al [3] first convert pixels from RGB to HSV, then remove black pixels by thresholding V-values and remove background pixels with a PCA model, and finally obtain the remaining color strings.…”

A Model-Based Field Frame Detection for Handwritten Filled-in Forms

“…Among them, [14] and [12] use corners and junctions in the image to define the fields, [5] uses vertical and horizontal projections, and [1] employs special structures of connected strips to extract the field boundaries. Some recent works deal with special situation such as color images [10] or patterned backgrounds and noisy images [13], [9], [17].…”

Unsupervised Decomposition of Color Document Images by Projecting Colors to a Spherical Surface

“…Sherkat et al [1] proposed a quite simple and fast method to decompose a color document into several layers. A default set of color classes is defined before decomposition.…”