[Measurement of gradation curve by the digital test pattern method in a computed radiography system].
Computed radiography (CR) has many variations in gradation, and it is difficult to grasp all of them. We produced the Digital Test Pattern, a step chart made based on digital values that was created by personal computer using Binary Editor. Image data input in the CR system is replaced with the Digital Test Pattern data. A gradation curve is measuring for using the processed output image data in the CR system, such that we can determine the relation between input and output. We termed this the Digital Test Pattern method. Output characteristics after gradation processing are obtained by output signal value and input signal value. Input is known beforehand, and change in the gradation processing parameter is understood from the output pixel value. It is also possible to measure a gradation curve directly from photographic density. Measuring the relation of input and output enabled computer simulation of a gradation curve. These studies indicated the effectiveness of our proposed method in terms of accuracy and ease of use.
Funamizu
Kenichi
K
Department of Radiology, Goshogawara City Hospital.
Yagihashi
Ruriko
R
Satou
Mitsuei
M
Kogawa
Katsufumi
K
D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D011856:Radiographic Image Enhancement / Q000295:instrumentation / Q000379:methods*