μSPIM: A Software Platform for Selective Plane Illumination Microscopy

Selective Plane Illumination Microscopy (SPIM) is a fluorescence imaging technique that allows volumetric imaging at high spatio-temporal resolution to monitor neural activity in live organisms such as larval zebrafish. A major challenge in the construction of a custom SPIM microscope is the control and synchronization of the various hardware components. Here we present a control toolset, μSPIM, built around the open-source MicroManager platform that has already been widely adopted for the control of microscopy hardware. Installation of μSPIM is relatively straightforward, involving a single C++ executable and a Java-based extension to Micro-Manager. Imaging protocols are defined through the μSPIM extension to Micro-Manager. The extension then synchronizes the camera shutter with the galvanometer mirrors to create a light-sheet that is scanned in the z-dimension, in synchrony with the imaging objective, to produce volumetric recordings. A key advantage of μSPIM is that a series of calibration procedures optimizes acquisition for a given set-up making it relatively independent of the optical design of the microscope, or the hardware used to build it. Two laser illumination arms can be used while also allowing for the introduction of illumination masks. μSPIM allows imaging of calcium activity throughout the brain of larval zebrafish at rates of 100 planes per second with single cell resolution as well as slower imaging to reconstruct cell populations, for example, in the cleared brains of mice.

Velocity Detection from a Motion Blur Image Using Radon Transformation

Motion blur is the result when the camera shutter remains open for an extended period of time and a relative motion between camera and object occurs. An approach for velocity detection based on motion blurred images has been implemented by the Radon transformation. The motion blur parameters are first estimated from the acquired images by using Radon transformation and then used to detect the speed of the moving object in the scene. Here established a link between the motion blur information of a 2D image and camera manufacturer’s data sheet and its calibration

ACS/WFC Pixel History, Bringing the Pixels Back to Science

Excess thermal energy within a Charged Coupled Device (CCD) results in excess electrical current that is trapped within the lattice structure of the electronics. This excess signal from the CCD itself can be present through multiple exposures, which will have an adverse effect on its science performance unless it is corrected for. The traditional way to correct for this extra charge is to take occasional long-exposure images with the camera shutter closed. These images, generally referred to as “dark” images, allow for the measurement of thermal-electron contamination at each pixel of the CCD. This so-called “dark current” can then be subtracted from the science images by re-scaling to the science exposure times. Pixels that have signal above a certain value are traditionally marked as “hot” and flagged in the data quality array. Many users will discard these pixels as being bad. However, these pixels may not be bad in the sense that they cannot be reliably dark-subtracted; if these pixels are shown to be stable over a given anneal period, the charge can be properly subtracted and the extra Poisson noise from this dark current can be taken into account and put into the error arrays.

An Arc Welder Monitoring System Research and Design of High-Speed Camera Trigger

Based on CO2 gas shielded arc welding of short circuit transfer welding current waveform changes with microcontroller core control with TTL counter as a basic circuit, the design an arc welder monitoring system the high-speed camera composition trigger circuit to solve the high-speed camera shutter trigger open the question of and actual monitoring system is verified.

Simulation Analysis of a Miniature Shutter Unit Using an Electromagnet for Digital Still Cameras and Video Cameras

Customers require that camera shutter and diaphragm size and power consumption are minimized but shutter speed maximized for the electromagnetic shutter units used in digital still-camera and video cameras. This paper describes the problems with past shutter and diaphragm units and proposes a new shutter unit based on simulation analysis. We compare the prototype model with simulated shutter speed data. Experimental results ascertain the effectiveness of this approach. Simulation results agreed quite well with experimental results.