MTF for Bayer pattern color detector

Elor, Yotam; Pinsky, Ephi; Yaacobi, Ami

doi:10.1117/12.723140

Cited by 11 publications

(6 citation statements)

References 5 publications

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“…Indeed, the MTF and resolution performance may seem poor compared to other imaging systems; this is at least partly a result of the effect of the Bayer pattern color filter array bonded on top of the Mastcam CCDs. Bayer pattern filters like this have been shown to create a significant decrease (a factor of 2 or more) in imaging system MTF compared to monochrome systems [e.g., Yotam et al ., ].…”

Section: Preflight Camera Testing and Calibration: Methods Data Setsmentioning

confidence: 97%

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The Mars Science Laboratory Curiosity rover Mastcam instruments: Preflight and in‐flight calibration, validation, and data archiving

Fraeman

Godber

McNair

et al. 2017

Earth and Space Science

142

245

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The NASA Curiosity rover Mast Camera (Mastcam) system is a pair of fixed-focal length, multispectral, color CCD imagers mounted~2 m above the surface on the rover's remote sensing mast, along with associated electronics and an onboard calibration target. The left Mastcam (M-34) has a 34 mm focal length, an instantaneous field of view (IFOV) of 0.22 mrad, and a FOV of 20°× 15°over the full 1648 × 1200 pixel span of its Kodak KAI-2020 CCD. The right Mastcam (M-100) has a 100 mm focal length, an IFOV of 0.074 mrad, and a FOV of 6.8°× 5.1°using the same detector. The cameras are separated by 24.2 cm on the mast, allowing stereo images to be obtained at the resolution of the M-34 camera. Each camera has an eight-position filter wheel, enabling it to take Bayer pattern red, green, and blue (RGB) "true color" images, multispectral images in nine additional bands spanning~400-1100 nm, and images of the Sun in two colors through neutral density-coated filters. An associated Digital Electronics Assembly provides command and data interfaces to the rover, 8 Gb of image storage per camera, 11 bit to 8 bit companding, JPEG compression, and acquisition of high-definition video. Here we describe the preflight and in-flight calibration of Mastcam images, the ways that they are being archived in the NASA Planetary Data System, and the ways that calibration refinements are being developed as the investigation progresses on Mars. We also provide some examples of data sets and analyses that help to validate the accuracy and precision of the calibration.Plain Language Summary We describe the calibration and archiving of the images being obtained from the Mastcam multispectral, stereoscopic imaging system on board the NASA Curiosity Mars rover. Calibration is critical to detailed scientific analysis of instrumental data, and in this paper we not only describe the details of the calibration process and the steps in our resulting data calibration pipeline but also present some examples of the kinds of scientific analyses and discoveries that this calibration has enabled.

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Section: Preflight Camera Testing and Calibration: Methods Data Setsmentioning

confidence: 97%

“…Earth and Space Science 10.1002/2016EA000219 bonded on top of the Mastcam CCDs. Bayer pattern filters like this have been shown to create a significant decrease (a factor of 2 or more) in imaging system MTF compared to monochrome systems [e.g., Yotam et al, 2007]. 3.2.9.…”

Section: 1002/2016ea000219mentioning

confidence: 99%

The Mars Science Laboratory Curiosity rover Mastcam instruments: Preflight and in‐flight calibration, validation, and data archiving

Fraeman

Godber

McNair

et al. 2017

Earth and Space Science

142

245

View full text Add to dashboard Cite

show abstract

“…Junocam uses an optical design nearly identical to that of MARDI, and the same detector as the MSL cameras but without the Bayer color filter array (CFA). It is known that Bayer CFAs reduce the spatial frequency response at Nyquist by a factor of 2 [ Yotam et al ., ]. Spatial frequency is the number of light‐to‐dark transitions per unit distance.…”

Section: Mardi Characterization and Calibrationmentioning

confidence: 99%

The Mars Science Laboratory (MSL) Mast cameras and Descent imager: Investigation and instrument descriptions

Malin

Ravine

Caplinger

et al. 2017

Earth and Space Science

142

166

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The Mars Science Laboratory Mast camera and Descent Imager investigations were designed, built, and operated by Malin Space Science Systems of San Diego, CA. They share common electronics and focal plane designs but have different optics. There are two Mastcams of dissimilar focal length. The Mastcam‐34 has an f/8, 34 mm focal length lens, and the M‐100 an f/10, 100 mm focal length lens. The M‐34 field of view is about 20° × 15° with an instantaneous field of view (IFOV) of 218 μrad; the M‐100 field of view (FOV) is 6.8° × 5.1° with an IFOV of 74 μrad. The M‐34 can focus from 0.5 m to infinity, and the M‐100 from ~1.6 m to infinity. All three cameras can acquire color images through a Bayer color filter array, and the Mastcams can also acquire images through seven science filters. Images are ≤1600 pixels wide by 1200 pixels tall. The Mastcams, mounted on the ~2 m tall Remote Sensing Mast, have a 360° azimuth and ~180° elevation field of regard. Mars Descent Imager is fixed‐mounted to the bottom left front side of the rover at ~66 cm above the surface. Its fixed focus lens is in focus from ~2 m to infinity, but out of focus at 66 cm. The f/3 lens has a FOV of ~70° by 52° across and along the direction of motion, with an IFOV of 0.76 mrad. All cameras can acquire video at 4 frames/second for full frames or 720p HD at 6 fps. Images can be processed using lossy Joint Photographic Experts Group and predictive lossless compression.

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“…The MTF for the registration algorithm ͑given by the quotient of the mean registered MTF and the original MTF͒ is also shown, suggesting a low-pass characteristic comparable to that of the detector MTF. The small jump in the MTF at 3.1 mm −1 is believed to be associated with the registration algorithm ͑likely due to "spurious" response of the bilinear interpolation filter 35 applied in the image transformation͒. The algorithm therefore imparts a characteristic blurring of the transformed image.…”

Section: Iiic Effect On Spatial Resolutionmentioning

confidence: 99%

Multiscale deformable registration for dual‐energy x‐ray imaging

et al. 2009

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Dual-energy ͑DE͒ imaging of the chest improves the conspicuity of subtle lung nodules through the removal of overlying anatomical noise. Recent work has shown double-shot DE imaging ͑i.e., successive acquisition of low-and high-energy projections͒ to provide detective quantum efficiency, spectral separation ͑and therefore contrast͒, and radiation dose superior to single-shot DE imaging configurations ͑e.g., with a CR cassette͒. However, the temporal separation between highenergy ͑HE͒ and low-energy ͑LE͒ image acquisition can result in motion artifacts in the DE images, reducing image quality and diminishing diagnostic performance. This has motivated the development of a deformable registration technique that aligns the HE image onto the LE image before DE decomposition. The algorithm reported here operates in multiple passes at progressively smaller scales and increasing resolution. The first pass addresses large-scale motion by means of mutual information optimization, while successive passes ͑2-4͒ correct misregistration at finer scales by means of normalized cross correlation. Evaluation of registration performance in 129 patients imaged using an experimental DE imaging prototype demonstrated a statistically significant improvement in image alignment. Specific to the cardiac region, the registration algorithm was found to outperform a simple cardiac-gating system designed to trigger both HE and LE exposures during diastole. Modulation transfer function ͑MTF͒ analysis reveals additional advantages in DE image quality in terms of noise reduction and edge enhancement. This algorithm could offer an important tool in enhancing DE image quality and potentially improving diagnostic performance.

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MTF for Bayer pattern color detector

Cited by 11 publications

References 5 publications

The Mars Science Laboratory Curiosity rover Mastcam instruments: Preflight and in‐flight calibration, validation, and data archiving

The Mars Science Laboratory Curiosity rover Mastcam instruments: Preflight and in‐flight calibration, validation, and data archiving

The Mars Science Laboratory (MSL) Mast cameras and Descent imager: Investigation and instrument descriptions

Multiscale deformable registration for dual‐energy x‐ray imaging

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