Fig. 3: Characterizing size-selective imaging processor with artificial targets.

a The experimental resolution of the size-selective imaging processor under red (λ = 650 nm), green (λ = 532 nm), and blue (λ = 466 nm) lights. Under red and green lights, the processor demonstrates selective edge detection with sizes ranging from 1.6 to 2.3 μm and 0.9 to 1.6 μm, respectively. The insets depict the ideal optical transfer function of the image processor (dashed line) and the measured optical transfer function (solid line) at different operating wavelengths. Furthermore, under blue light, the processor efficiently engages in selective denoising of noise with a size less than 0.3 μm. Conversely, it preserves information when the noise size is 0.4 μm, as depicted in the inset that provides a magnified view of the retained noise. b The processor’s size-selective edge detection capability with artificial targets of diverse letters and shapes under red and green lights, encompassing the letters ‘A’ to ‘I’, the optical field vector diagram denoted as ‘E–H–K’, and the ‘Schrödinger staircase’. Specifically, under red light, the processor discernibly enhances the edges of letters ‘D’ to ‘I’ (size: 1.6–2.3 μm) and the letter ‘H’ with its axis (size of 2.2 μm). Conversely, under green light, the edge enhancement is observed on letters ‘A’ to ‘D’ (size: 1–1.6 μm) and the letter ‘E’ with its axis (size = 1.4 μm). Moreover, the ‘Schrödinger staircase’ achieves its artistic effect by designing the sizes of the upper (size of 2.3 μm) and side (size of 1.2 μm) surfaces. Consequently, the staircase imparts downward and upward visual effects under red and green light, respectively. The insets display locally magnified details of the structural features of the edges. c The size-selective denoising capability of the processor through the examination of the letters ‘RGB’, the ‘satellite’, and a QR code, with the size of the noise being 0.3 μm. In comparison to the results obtained through bright field imaging, the noise surrounding the letter ‘B’, the ‘satellite’, and the QR code is efficiently eliminated following the denoising.