The coded aperture imaging technique is a useful method of x-ray imaging in observational astrophysics. However, the presence of imaging noise or so-called artifacts in a decoded image is a drawback of this method. We propose a coded aperture imaging method using multiple different random patterns for significantly reducing the image artifacts. This aperture mask contains multiple different patterns each of which generates a different artifact distribution in its decoded image. By summing all decoded images of the different patterns, the artifact distributions are cancelled out, and we obtain a remarkably accurate image. We demonstrate this concept with imaging experiments of a monochromatic 16-keV hard x-ray beam at the synchrotron photon facility SPring-8, using the combination of a complementary metal-oxide-semiconductor image sensor and an aperture mask that has four different random patterns composed of holes with a diameter of 27 μm and a separation of 39 μm. The entire imaging system is installed in a 25-cm-long compact size and achieves an angular resolution of <30 arc sec (full-width at half-maximum). In addition, we show by Monte Carlo simulation that the artifacts can be reduced more effectively if the number of different patterns increases to 8 or 16.

中文翻译：

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具有多个不同随机模式的X射线带中的无伪像的编码孔径成像

编码孔径成像技术是观测天体物理学中X射线成像的一种有用方法。然而，在解码图像中存在成像噪声或所谓的伪像是该方法的缺点。我们提出一种编码孔径成像方法，该方法使用多个不同的随机图案来显着减少图像伪像。该孔径掩模包含多个不同的图案，每个图案在其解码图像中生成不同的伪像分布。通过对不同模式的所有解码图像求和，可以消除伪影分布，从而获得非常准确的图像。我们通过在同步加速器光子设施SPring-8上对单色16-keV硬X射线束进行成像实验来证明这一概念，结合使用互补金属氧化物半导体图像传感器和孔径掩模，该孔径掩模具有四个不同的随机图案，这些图案由直径为27μm，间距为39μm的孔组成。整个成像系统以25厘米长的紧凑尺寸安装，并实现了小于30弧秒的角分辨率（半高全宽）。另外，我们通过蒙特卡洛模拟表明，如果不同图案的数量增加到8或16，则可以更有效地减少伪影。