Converting color or grayscale images to black and white is often necessary in document management applications. Although many document management application and most recognition engines operate on black and white images, it does make sense to scan them in color or grayscale. The idea behind this is that color and grayscale images carry a lot more information than their "scanner converted" bi-tonal counterpart.

While most documents are easy to convert, a number of them can be quite challenging. Especially when documents of different characteristics are scanned in the same batch. Everybody involved in document management had to face scanning invoices or bill of leading from different vendors with varying degree of clarity.

The following images where scanned using the same scanner sensitivity settings and converted with Coladapt using automatic settings. Note that Coladapt gained in both legibility and file size.

Click on the thumbnail images to view in full size (640 x 523 ). Each type of image will be shown in its own browser window. Bitonal images are shown in GIF format for browser compatibility. Coladapt output uses TIFF format and the TIFF image size is show for each image.

	Original	Scanner	Coladapt
bad carbon copy		15 Kb	5 Kb
many shaded areas		34 Kb	6 Kb
colored background		9 Kb	8 Kb
exhausted printer ribbons		15 Kb	5 Kb
old typewriter ribbons (grayscale image)		22 Kb	4 Kb
Applying heavy filtering on last image can yield

Scanners are not designed to handle these situations in an optimal fashion. Coladapt is a software product that performs this conversion. As the name implies, it does it by adapting its threshold method to both global and local characteristics of the document.

You may download a demo version of this program.

Click here for Demoadapt.zip.

It is 5 440 KB and it contains a full installation script, with demo files.