GB Soft/document imaging/DjVu/damaged documentation       main page: www.djvu.com.pl 

Archivization example for damaged technical documentation*

There are 4 examples of archivization for paper technical drawings to binary DjVu files below. Each drawing is stored in 3 separate files which are displayed as thumbnails.
Thumbnail in first column presents file acquired directly from large format scanner without any integration into image. There is required fast computer to open images like this or expensive commercial graphics software (e.g. Adobe PhotoShop). Moreover processing time for such images is so long that it practically precludes natural reading. Source JPEG files are not included on www because of their large sizes. Thumbnails in second and third columns present documents in DjVu format. Conversion to DjVu was made using special conversion profiles for damaged documentation optimized in GB Soft.
The first profile emphasizes on trusty appearance and maximum readability, the second profile emphasizes contrast and details readability which affects image without yellow shades and dark background. They were omited by optimized profile during conversion.
Comparation of files sizes is very interesting. In case of ram drawing, DjVu file is 2200 times smaller than corresponding JPEG file. Quality of DjVu file can be appreciated after reading below links for profile 1 and profile 2. Opening time is satisfactory as well as navigation smoothness delivered by DjVu browser. Usefulness of image segmentation which is the base of DjVu standard can be appreciated with example of main servomotor where we can see only foreground layer of drawing or see its background layer and finally back to complete image .

DjVu technology as a base for archives, especially for scanned paper documents, allowes instant access to drawings with full quality and unbelievably small file sizes. It is impossible for other technologies like JPEG, TIFF, PDF. The next advantage is that document image in DjVu is uneditable which makes it more reliable.

(*) Below documents are published under acceptance of Zakłady Gumowe Górnictwa S.A.

Cap of ram (41.5 * 59.5 cm, 400dpi)



jpeg
15 416 KB


djvu 1
144 KB
0,93 %
1:1252
djvu 2
116 KB
0,75 %
1:1551
file size reduced more than 99%.
Scanned to jpg
DjVu, profile 1
DjVu, profile 2
summary

Ram (41.5 * 59.5 cm, 400dpi)




jpeg
15 324 KB

djvu 1
104 KB
0,67 %
1:1761
djvu 2
80 KB
0,52 %
1:2258
file size reduced more than 99%.
Scanned to jpg
DjVu, profile 1
DjVu, profile 2
summary

Pressure tank (46.6 * 59.6 cm, 400dpi)



jpeg
15 688 KB

djvu 1
122 KB
0,77 %
1:1660
djvu 2
110 KB
0,70 %
1:1837
file size reduced more than 99%.
Scanned to jpg
DjVu, profile 1
DjVu, profile 2
summary

Main servomotor (84.4 * 59.5 cm, 400dpi)




jpeg
32 589 KB

djvu 1
388 KB
1,19 %
1:939
djvu 2
245 KB
0,75 %
1:1482
file size reduced more than 98 i 99%.
Scanned to jpg
DjVu, profile 1
DjVu, profile 2
summary

To browse examples images from article it is required to install DjVu browser DjVu plugin