Evaluating noise in digitized radiographic images by means of histogram
DOI:
https://doi.org/10.1590/S1678-77572006000600005Keywords:
Digital image, Radiographic image, Scanners, Digital camera, Charge-coupled device, NoiseAbstract
To evaluate the performance of three digital devices regarding the noise added to digital radiographic images containing different optical densities. METHODS: A radiographic image was digitized repeatedly ten times using two scanners (HP 4c/T and HP 5370C) and a digital camera (Nikon 990). A histogram tool measured a mean pixel value and the standard deviation of the region of interest in each image. Both values were used to calculate the image noise at the different optical densities. RESULTS: The noise values found were different for all devices and optical densities. There was a statistically significant difference (p<0.05) between the scanner HP 4c/T and the digital camera regarding the noise values. There was a significant correlation (p<0.05) between the noise values found for the HP 4c/T scanner and the digital camera and between both scanners (p<0.01). CONCLUSION: The noise added to the image was higher for scanner HP 4c/T and less for the digital camera. The noise was higher at the lower optical densities for the scanners. It seems that depending on the equipment and the optical density, a variable amount of noise can be incorporated to the images.Downloads
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Published
2006-12-01
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Original Articles
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Todo o conteúdo do periódico, exceto onde está identificado, está licenciado sob uma Licença Creative Commons do tipo atribuição CC-BY.
How to Cite
Evaluating noise in digitized radiographic images by means of histogram . (2006). Journal of Applied Oral Science, 14(6), 410-414. https://doi.org/10.1590/S1678-77572006000600005