In 2004, Prof. Huib Simonsz acquired the unpublished Ph.D. thesis manuscript (205 typed-up pages) of A.B. de Haan, one of the original three creators of the orbita sections on this website.
The pages of the manuscript, titled “DE PRENATALE ONTWIKKELING VAN DE HUMANE ORBITA”, were digitised by Charl P. Botha and Sander Schutte in the same year, and much later, in 2021, re-OCRed to try to improve the text recognition in the PDF.
The recognised text is embedded along with the scanned versions of the typed pages so that full-text searches through the content work as usual.
Download: proefschrift ab dehaan g75 searchable ocr2021.pdf (33M)
Details of digitisation
The 205 pages were photographed in 2004 by Charl P. Botha using a borrowed Olympus C8080WZ digital camera on a tripod with fixed focus, automatic exposure and resolution 3264 x 2448.
“rotcrop95” contains the rotated and cropped images. Command used:
convert -quality 95 -rotate 270 -crop 1853x2636+308+292
“proefschrift_abdehaan_g75.pdf” is a contrast-corrected greyscaled PDF of the manuscript pages. They have been specially embedded as JPEGs to ensure a more managaeble filesize.
first rotcrop95 was converted to PGMs for greyscaling
The contrast correction was done with:
convert -quality 75 -level 0,1.0,50% (MAKE SURE TO USE IMAGEMAGICK 6.1.5). For images 604 to 619 this was:
The resultant jpegs were embedded in EPSs with
The PDF was created with:
gs -dBATCH -dNOPAUSE -dCompatibilityLevel=1.4 -q -sDEVICE=pdfwrite -sOutputFile=proefschrift_abdehaan_g75.pdf epss/PB*.eps
Sander Schutte then performed the first OCR of this version, and embedded the recognised text.
The final PDF that you can download from this page, is the same as above, but with a more modern OCR implementation applied in 2021 with PDF-XChange Editor 9.