A version control system is a must-have for every software developer. Read about our preliminary considerations, our experience with Bazaar and take your first steps with a small tutorial.

The idea of shutter speed measurement is quite simple. If you want to know, how precise the shutter of your digital camera works, you can test it for example with an LED panel, which provides some LEDs flashing up at a certain frequency. If you capture an image of this device, you can count the LEDs in the image and multiply them with the LED frequency to get the exposure time. If you repeat this several times, you can see how accurate the shutter works.

The dynamic range (DR) describes the maximum contrast ratio, which can be captured by a digital camera without highlight clipping and a signal in the dark patches which can be divided from noise. The dynamic range is a primary characteristic value of the image receiving sensor, but is influenced by the used lens in camera system and the image processing.

Color confusion: An attempt to describe the most used terms around color handling in digital imaging. Not an easy task because everybody knows that it only takes a single color expert to have an argument...
Color is an impression that requires the human being to recognize it.

Is it possible to use HD charts for SD and the other way round?

Often times the dynamic range that gets reported by imaging sensor manufacturers is based on the max output signal divided by the noise in the dark areas also called the noise equivalent power. The noise equivalent power describes the signal level where the signal is just as great as the noise – a so-called signal to noise ratio of 1. This basically represents the threshold above which a signal can be detected.

Standard for Measurement and Presentation of Specifications for Machine Vision Sensors and Cameras

There are phenomena in the area of physics and especially in optics that cannot be explained by geometry. A simple example is a water wave that strikes the entrance of a harbor. If this harbor entrance is narrow the new wave that extends in the harbor has the form of a wave as if a stone was thrown into the water. You can see the wave without being able to see the sea from which the wave came from.

In the TechNote ”The concept of noise reduction“ we presented the simple idea behind noise reduction. This idea is based on a seperation of the image in at least two parts (noise and image content). Sometimes it is quite hard to distinguish from noise and image content, especially if you handle with low contrast textures. So if we want to be able to make a statement of how good an algorithm works on that, we have to establish a new numeric quantity, which is called ”kurtosis“.

How to set up the correct light level with integrating sphere

Resolition is measured using edges, Siemens stars or other regular structures with íncreasing frequencies. Units like LW/PH, LP/PH, or Cycles per pixel are independent of the sensor size and the pixel pitch.

If you are using a scanner, you set the wished sampling rate of the scan. So if you set it to 300 PPI (pixel per inch), most people assume that they really get 300 PPI.

This can happen, but does not have to. If you really care about the sampling rate, you should check in detail. Especially for archives, this is important as people want to check the originals based on the scan. So if they want to know the size of the original, they need to know the real SAMPLING RATE.