9-11 Remembered in DjVu Broadsheet Newspaper Comparison

9-11 Remembered in DjVu Broadsheet Newspaper Comparison

A comparative test by James Rile, PlanetDjVu, October 8, 2002

DjVu Examples


Color	Enhanced Color	Grayscale	Bitonal

We took a sample broadsheet newspaper page, containing a memorable color image from the tragedy, and rendered it in 4 different ways to DjVu and PDF for comparision.

We first scanned and produced this sample page in the following raster image formats:

Full color at 300 dpi

Histogram-Enhanced full color at 300 dpi

Grayscale at 300 dpi

Bitonal at 300 dpi

Then we produced a searchable DjVu file and a searchable PDF file from each of these images.

Here are the results (click the size to open the corresponding file):

Source Image Type	DJVu Size	PDF Size
Full color at 300 dpi	164 Kb	4.96 Mb
Histogram-Enhanced full color at 300 dpi	208 Kb	5.07 Mb
Grayscale at 300 dpi	188 Kb	4.74 Mb
Bitonal at 300 dpi	642 Kb	1.15 Mb

You might ask why the bitonal file in DjVu is much larger than the color and grayscale files. The answer is that the photo takes up less storage space when it is saved into the background layer of the DjVu file, than when it is stored entirely in the foreground, bitonal layer of the DjVu file.

Judge for yourself which type of scan and which type of DjVu or PDF is best for your own newspaper imaging and conversion project! All DjVu and PDF files were produced and OCRed with JRAPublish.