Demosaicking for Color Filter Array Image Sensors by Restoring Blur Caused by an Optical Low-pass Filters( Image Sensing Technology and Their Applications)
Demosaicking for Color Filter Array Image Sensors by Restoring Blur Caused by an Optical Low-pass Filters( Image Sensing Technology and Their Applications)
复制标题
通过恢复光学低通滤波器引起的模糊来对彩色滤光片阵列图像传感器进行去马赛克（图像传感技术及其应用）
DOI：
10.3169/itej.59.407
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
T. Saito
中科院分区：
文献类型：
--
作者：
T. Komatsu;T. Saito
我们使用带有固态成像设备的光学低通滤光片来产生图像。实际的光学低通滤光片是由两种双折射晶体器件组合而成的。这种滤波器不能大幅切断高频分量，而是将奈奎斯特频率附近的频率分量降低。因此，在表面上投影的图像是模糊的。提出了一种恢复光学低通滤光片引起的模糊的去马赛克方法。我们的去马赛克锐化方法采用了Landweber类型的迭代算法。对于我们的锐化-去马赛克方法，RGB原色滤色器阵列的拜耳模式不适用。因此，我们研究了另一种滤色器模式，即WRB滤色器阵列，它比RGB滤色器阵列更可取，其中W滤光器意味着所有可见光都通过它。我们的锐化-去马赛克的数学公式类似于最小二乘问题，但有许多不同的最小二乘解。为了避免空间频域的二义性，我们在迭代算法中引入了与彩色滤光片镶嵌的子采样模式相对应的通带限制。
We used optical low-pass filters with solid-state imaging devices to produce images. The actual optical low-pass filter was formed by combining two types of doubly refractive crystal devices. The filters cannot sharply cut-off the high frequency components and they reduce the frequency components near the Nyquist frequency. Thus, the projected images on the surface are blurred. This paper presents a demosaicking method that restores the blur caused by optical low-pass filters. Our sharpening approach to demosaicking employs a Landweber-type iterative algorithm. For our sharpening-demosaicking approach, the Bayer's pattern of the RGB primary color filter array is not applicable. Therefore, we studied another color-filter pattern, namely the WRB filter array, which is preferable to the RGB filter array, where W-filtering means that all the visible light passes through it. Our mathematical formulations for sharpening-demosaicking are similar to the least square problem, but there are many different least square solutions. To avoid ambiguity in the spatial frequency domain, we introduced a pass-band limitation that corresponds with the sub-sampling pattern of the mosaicking of color filters into the iterative algorithm.