%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Duprey, Nicolas
%A Boucher, Hugues
%A Jimenez, C.
%T Digital correction of computed X-radiographs for coral densitometry
%D 2012
%L fdi:010058216
%G ENG
%J Journal of Experimental Marine Biology and Ecology
%@ 0022-0981
%K Calcification rate ; Coral densitometry ; Coral skeleton ; Density ; Porites sp. ; Siderastrea siderea
%K COSTA RICA ; NOUVELLE CALEDONIE ??
%M ISI:000312239200011
%P 84-92
%R 10.1016/j.jembe.2012.09.007
%U https://www.documentation.ird.fr/hor/fdi:010058216
%> https://www.documentation.ird.fr/intranet/publi/2013/01/010058216.pdf
%V 438
%W Horizon (IRD)
%X The recent increase in sea surface temperature and ocean acidification raises major concerns about the evolution of the coral calcification rate. Digitized X-radiographs have been used for coral skeleton density measurements since the 1980s. The main limitation of coral densitometry from digitized X-radiographs is the X-ray intensity heterogeneity due to spherical spreading (inverse square law) and heel effect. Until now, extra X-ray images or aluminum standards have been used to correct X-radiographs. However, such corrective methods may be constraining when working with a high number of coral samples. Here, we present an inexpensive, straightforward, and accurate digital detrending (DD) method to correct the heterogeneities of the X-ray irradiation that affect X-radiographs. The X-radiograph is corrected against the irradiation imprint recorded by its own background using a kriging interpolation method, thus allowing reliable optical density measurements directly on the corrected X-ray image. This digital detrending (DD) method was validated using skeletal bulk density measurements and computerized tomography (CT). Coral densitometry using DD corrected X-radiographs does not require the destruction of the coral sample and provides high-resolution measurements. Since DD does not require extra aluminum standards to correct X-radiographs, this method optimizes the working space available on the X-ray image. Moreover, it corrects the entire X-radiograph, thus larger samples or numerous samples can be X-rayed at the same time.
%$ 036 ; 020