~Xenos peckii復(fù)眼和節(jié)肢動物復(fù)眼的比較，以及受Xenos peckii眼啟發(fā)的相機(jī)設(shè)計~

A comparison of the eye of Xenos peckii and the arthropod eye, and a camera designs inspired by the eye of Xenos peckii

大自然中的復(fù)眼因其在廣闊視野中捕捉視覺信息的卓越能力廣受研究人員關(guān)注。在這些復(fù)雜的光學(xué)系統(tǒng)中，Xenos peckii，一種扭紋蟲昆蟲，的復(fù)眼和節(jié)肢動物的復(fù)眼的高效的視覺感知便是一個引人注目的例子。本報告旨在探索和比較Xenos peckii的復(fù)眼和節(jié)肢動物復(fù)眼的獨特特征，并深入探討受這些自然奇觀啟發(fā)的相機(jī)系統(tǒng)的設(shè)計和開發(fā)。通過理解這些復(fù)眼的結(jié)構(gòu)和功能方面，我們可以揭示相機(jī)技術(shù)領(lǐng)域的新見解和潛在應(yīng)用。通過這次探索，我們將發(fā)現(xiàn)復(fù)眼如何激發(fā)創(chuàng)新的成像系統(tǒng)解決方案。

Compound eyes found in nature have fascinated researchers for their remarkable ability to capture visual information across a wide field of view. Among these intricate optical systems, the eye of Xenos peckii, a strepsipteran insect, and the compound eyes of arthropods stand out as captivating examples of efficient visual perception. This report aims to explore and compare the unique characteristics of Xenos peckii's compound eye and the arthropod eye, as well as delve into the design and development of a camera systems inspired by these natural wonders. By understanding the structural and functional aspects of these compound eyes, we can uncover novel insights and potential applications in the field of camera technology. Through this exploration, we will discover how compound eyes can inspire innovative solutions for imaging systems.

X. peckii的獨特復(fù)眼?

X. peckii的復(fù)眼與典型的節(jié)肢動物復(fù)眼相比具有獨特的特點。與果蠅等其他小昆蟲的眼睛有700多個小結(jié)構(gòu)不同，X. peckii的眼睛大約有50個較大的透鏡（1）。X. peckii中的每個透鏡直徑約為65 μm，覆蓋了相當(dāng)于果蠅中15個透鏡的面積（圖1，Buschbeck et al., 1999）。

The compound eye of X. peckii, a strepsipteran insect, exhibits unique characteristics compared to typical arthropod eyes. Unlike other small insects like Drosophila melanogaster, which have over 700 facets in their eyes, X. peckii has around 50 larger lenses? (1). Each lens in X. peckii is approximately 65 μm in diameter and covers an area equivalent to 15 lenses in D. melanogaster (Figure 1, Buschbeck tet al., 1999).

X. peckii的眼由稱為眼小區(qū)的個體單位組成，每個眼小區(qū)都包含一個自己的視網(wǎng)膜，被色素囊圍繞（圖1，Maksimovic等人，2007）。光學(xué)測量結(jié)果表明，這些眼小區(qū)獨立地處理投射到它們各自視網(wǎng)膜上的視覺信息。與節(jié)肢動物眼不同，其中每個小結(jié)構(gòu)都有8至10個光感受器，X. peckii的擴(kuò)展視網(wǎng)膜含有100多個感受器細(xì)胞（2, 4）。因此，X. peckii眼中的視野被劃分為“塊”，而不是被分解為單個點。這種獨特的結(jié)構(gòu)使得每個眼小區(qū)能夠?qū)⒁曇爸械奈矬w清晰地聚焦（圖3.A和B，Buschbeck等人，1999）。

The eye of X. peckii consists of individual units called eyelets, each containing its own retina surrounded by a pigmented cup (Figure 1, Maksimovic et al., 2007). Optical measurements suggest that these eyelets function independently to process the visual information projected onto their respective retinas. Unlike arthropod eyes, where each facet contributes to a single sample point with 8 to 10 photoreceptors, X. peckii's extended retina contains over 100 receptor cells (2, 4). Consequently, the visual field in X. peckii's eye is divided into "chunks" rather than being decomposed into individual points. This unique structure enables each eyelet to bring an object in the visual field into clear focus (Figure 3. A and B, Buschbeck tet al., 1999)

X. peckii眼中眼小區(qū)的組織方式導(dǎo)致了復(fù)眼下方視覺系統(tǒng)的神經(jīng)解剖排列的差異。來自每個眼小區(qū)感受器細(xì)胞的投射形成一個在板狀區(qū)域（圖2A）終止并繞其軸線扭曲（圖2B，Buschbeck等人，1999），從而使每個視網(wǎng)膜在板狀區(qū)域上的空間表示大約旋轉(zhuǎn)了180度。

The organization of eyelets in X. peckii leads to differences in the neuroanatomical arrangement of the visual system beneath the compound eyes. The projections of the receptor cells from each eyelet form a nerve that terminates in the lamina (Figure 2A) and twists around its axis (Figure 2B, Buschbeck tet al., 1999), resulting in a rotation of the spatial representation of each retina on the lamina by approximately 180 degrees.

基于這些解剖數(shù)據(jù)，研究人員提出了X. peckii眼中視覺處理的模型（圖4B），說明它與傳統(tǒng)復(fù)合眼（圖4A）的顯著差異。使用顏色來表示圖像的表示。在左側(cè)的并置眼中，每個光學(xué)單位只表示一個采樣點。圖像的相鄰點在視網(wǎng)膜和板狀區(qū)域的水平上以及旁邊表示。在右側(cè)顯示的X. peckii眼中，圖像通過多個眼小區(qū)查看，每個透鏡捕捉部分圖像。由于每個透鏡都具有圖像反轉(zhuǎn)作用，整個圖像在視網(wǎng)膜層次上失去了連貫性，但在視網(wǎng)膜和板狀區(qū)域之間的神經(jīng)扭曲中得以恢復(fù)（2）。這種復(fù)合透鏡眼睛的優(yōu)勢在于具有高光聚集能力和圖像分辨率的結(jié)合，否則在小昆蟲中很難實現(xiàn)（1）。

On the basis of these anatomical data, researchers have proposed a model for visual processing in X. peckii's eye, (Figure 4B) illustrating its substantial deviation from conventional compound eyes (Figure 4A). Color is used to depict the representation of an image. In the apposition eye on the left, each optic unit only represents one sample point. Neighboring points of an image are represented next to each other at the level of the retina as well as the lamina. In the eye of X. peckii shown on the right, the image is viewed through multiple eyelets, with each lens capturing a partial image. Because each lens is image-reversing, the coherence of the entire image is lost a the level of the retina, but is restored by the physical twisting of the nerves between the retina and the lamina (2). The advantage of such a composite-lens eye lies in a combined high light-gathering ability and image resolution that otherwise would be difficult to achieve in small insects (1).

基于X. peckii眼的高對比度和高分辨率成像的超薄陣列相機(jī)

Ultra-thin arrayed camera for high-contrast and high-resolution imaging inspired by the eye of X. peckii

在最近的研究中，人們采用各種微納制造方法結(jié)合受生物啟發(fā)的相機(jī)，創(chuàng)建了微透鏡陣列。這些方法，如熱流變、噴墨打印和三維直接激光寫入，仍在開發(fā)中，以解決微透鏡之間的光學(xué)串?dāng)_問題，以實現(xiàn)高對比度成像。傳統(tǒng)的光吸收器，如疊層玻璃光闌陣列或加工的光折射器陣列，在減少光學(xué)串?dāng)_方面也有其局限性（5,6）。

In recent studies, various micro-fabrication methods have been employed in combination with biologically inspired cameras to create micro-lens arrays. These methods, such as thermal reflow, inkjet printing, and 3D direct laser writing, are still being developed to address the issue of optical crosstalk between micro-lenses in order to achieve high-contrast imaging. Traditional light absorbers, like glass stacked diaphragm arrays or machined baffle arrays, also have their own limitations in reducing optical crosstalk (5,6).

受X. peckii獨特視覺系統(tǒng)的啟發(fā)，韓國科學(xué)技術(shù)高等研究院的研究人員開發(fā)了一種超薄陣列相機(jī)。該相機(jī)由多層孔徑陣列（MAAs）、倒置微透鏡陣列（iMLAs）和平面CMOS圖像傳感器上的間隙間隔器組成。

Taking inspiration from the unique visual system of X. peckii and aiming to overcome these technical limitations, researchers from the Korea Advanced Institute of Science and Technology have developed an ultra-thin arrayed camera. This camera consists of multilayered aperture arrays (MAAs), inverted micro-lens arrays (iMLAs), and gap spacers on a planar CMOS image sensor.

MAAs由堆疊的黑色聚合物圓形圖案組成，用作圓柱形針孔陣列。這些陣列在可見光譜范圍內(nèi)高效吸收光線，顯著減少了微透鏡之間的光學(xué)串?dāng)_。iMLAs位于MAAs中的針孔下方，與傳統(tǒng)向上微透鏡陣列相比，提供了相對較大的視場（FOV），因為它們允許來自前玻璃窗口的折射光以額外的角度進(jìn)入單個微透鏡。MAAs的厚度為60微米，孔徑直徑為35微米，F(xiàn)OV約為70°（3）。

The MAAs are composed of stacked black polymer circular patterns that serve as cylindrical pinhole arrays. These arrays efficiently absorb light across the visible spectrum, significantly reducing optical crosstalk between micro-lenses. The iMLAs, placed beneath the pinholes in the MAAs, offer a relatively larger field of view (FOV) compared to traditional upward micro-lens arrays because they allow refracted light from a front glass window to enter individual micro-lenses at an additional angle. With a thickness of 60 μm and an aperture diameter of 35 μm, the FOV of the MAAs is approximately 70° (3).?

通過iMLAs和MAAs，遠(yuǎn)場平面上的物體被成像到每個通道上。由于每個通道的視差很小，這些陣列圖像是均勻的，但稍有不同。最后，可以使用右側(cè)顯示的超分辨率算法從陣列圖像中重建出單個高分辨率圖像，該算法通過最小化圖像與數(shù)據(jù)之間的LP范數(shù)（p=2），并結(jié)合基于先驗知識的正則化項和λ權(quán)重。

Through the iMLAs and MAAs, objects located in the far-field plane are imaged on each channel. Due to the small visual disparity of each channel, these array images are uniform but are slightly different. Lastly, a single high-resolution image can be reconstructed from the array images by using a super-resolution algorithm shown on the right that? minimizes the LP norm (p=2) between the images and the data, incorporating a regularization term based on the prior and a lambda weight.

實驗結(jié)果表明，相機(jī)的多層針孔結(jié)構(gòu)通過消除光學(xué)串?dāng)_實現(xiàn)了高對比度成像。通過僅通過MAAs、僅通過iMLAs和組合的MAAs和iMLAs（稱為MOE）捕捉532納米激光束的分割圖像，顯示MOE產(chǎn)生了不帶有任何微透鏡之間的光學(xué)串?dāng)_的銳利聚焦光束（圖3a）。MOE的強(qiáng)度分布曲線（圖3b）還表明銳利的峰值信號，沒有噪聲或串?dāng)_，明確顯示了光束聚焦和光線阻斷。此外，通過僅使用iMLAs和MOE捕捉的棋盤格圖像（圖3d）清楚地表明MOE提供了比僅使用iMLAs更高的對比度。

Experimental results demonstrate that the multilayered pinhole structure of the camera enables high-contrast imaging by eliminating optical crosstalk. Sectioned images of a 532-nm laser beam passing through the MAAs only, iMLAs only, and the combined MAAs and iMLAs (referred to as MOE) show that the MOE produces sharp focused beams without any optical crosstalk between micro-lenses (Figure 3a). Intensity profiles of the MOE? (Figure 3b) also indicate a sharp peak signal without noise or crosstalk, clearly demonstrating beam focusing and light blocking. In addition, the images of a checkerboard captured through the iMLAs only and with the MOE (Figure 3d) clearly indicate that the MOE provides higher contrast than only the iMLAs.

通過捕捉和重建骰子的圖像，演示了超薄陣列相機(jī)的重建能力（圖4a）。重建的圖像顯示邊緣清晰度和對比度增加，調(diào)制傳遞函數(shù)（MTF）隨合并通道圖像數(shù)量呈對數(shù)增加。研究人員還通過使用歐幾里德距離測量目標(biāo)對象（圖4d）和獲取的圖像（圖4e和f）之間的顏色差異，對超薄陣列相機(jī)的重建圖像進(jìn)行了比較，顯示出單通道圖像的歸一化顏色差異為0.31，重建圖像為0.08。

The camera's reconstruction capabilities are demonstrated through capturing and reconstructing images of a dice (Figure 4a). The reconstructed images exhibit increased edge sharpness and contrast, and the modulation transfer function (MTF) logarithmically increases with the number of merged channel images. The researchers also captured images of a red parrot to measure the color differences between the target object (Figure 4d) and acquired images (Figure 4e and f) using the Euclidean distance, which exhibits a normalized color difference of 0.31 for the single channel image and 0.08 for the reconstructed image.

將超薄陣列相機(jī)應(yīng)用于光學(xué)顯微鏡和工業(yè)檢測等領(lǐng)域可以為高分辨率和高對比度成像提供新的解決方案。此外，這種受X. peckii復(fù)合眼啟發(fā)的相機(jī)設(shè)計還為未來的顯微成像和攝影技術(shù)提供了新的思路和創(chuàng)新潛力。

The reconstructed images from the ultra-thin arrayed camera were further compared with those from a commercialized compact camera. Compared to commercial compact cameras or mobile cameras, the ultra-thin arrayed camera exhibited exceptional figures of merit, including image resolution, FOV that is 1.5 times of the FOV of a commercial camera, a substantial improvement of 5.41 times in the TTL and cost-effectiveness. Such properties of the ultra-thin camera provides new opportunities for diverse mobile, surveillance, or medical applications.

總結(jié)

X. peckii的復(fù)眼和節(jié)肢動物眼在結(jié)構(gòu)和功能上存在差異。X. peckii的眼由較少數(shù)量的大型透鏡組成，每個透鏡覆蓋了較大的視野，并具有更多的感受器細(xì)胞。這種結(jié)構(gòu)使得X. peckii能夠以高分辨率和高對比度聚焦視野中的物體。

基于X. peckii眼的啟發(fā)，研究人員開發(fā)了一種超薄陣列相機(jī)，利用多層孔徑陣列和倒置微透鏡陣列來實現(xiàn)高對比度和高分辨率成像。實驗證明，該相機(jī)具有消除光學(xué)串?dāng)_的能力，并能夠重建出銳利、清晰的圖像。

這些研究揭示了復(fù)合眼在相機(jī)技術(shù)中的潛在應(yīng)用，為顯微成像和攝影領(lǐng)域的創(chuàng)新提供了新的思路和解決方案。通過借鑒自然界的設(shè)計原理，我們可以進(jìn)一步改進(jìn)和發(fā)展相機(jī)技術(shù)，以實現(xiàn)更高質(zhì)量的圖像和更廣闊的應(yīng)用領(lǐng)域。