Author Archives: DXOMARK

We propose an objective measurement protocol to evaluate the autofocus performance of a digital still camera. As most pictures today are taken with smartphones, we have designed the first implementation of this protocol for devices with touchscreen trigger.

This paper presents a novel device and algorithms for measuring the different timings of digital cameras shooting both still images and videos. These timings include exposure (or shutter) time, electronic rolling shutter (ERS), frame rate, vertical blanking, time lags, missing frames, and duplicated frames.

We present in this paper a novel capacitive device that stimulates the touchscreen interface of a smartphone (or of any imaging device equipped with a capacitive touchscreen) and synchronizes triggering with our LED Universal Timer to measure shooting time lag and shutter lag according to ISO 15781:2013.

This article presents a system and a protocol to characterize image stabilization systems both for still images and videos.

The I3A Camera Phone Image Quality (CPIQ) initiative aims to provide a consumer-oriented overall image quality metric for mobile phone cameras. In order to achieve this goal, a set of subjectively correlated image quality metrics has been developed. This paper describes the development of a specific group within this set of metrics, the spatial metrics. […]

Digital sensors have obviously invaded the photography mass market. However, some photographers with very high expectancy still use silver halide film. Are they only nostalgic reluctant to technology or is there more than meets the eye? The answer is not so easy if we remark that, at the end of the golden age, films were […]

Extended depth of field (EDOF) cameras have recently emerged as a low-cost alternative to autofocus lenses. Different methods, either based on longitudinal chromatic aberrations or wavefront coding have been proposed and have reached the market. The purpose of this article is to study the theoretical performance and limitation of wavefront coding approaches. 

The aim of the paper is to define an objective measurement for evaluating the performance of a digital camera. The challenge is to mix different flaws involving geometry (as distortion or lateral chromatic aberrations), light (as luminance and color shading), or statistical phenomena (as noise). . 

We describe the procedure to evaluate the image quality of a camera in terms of texture preservation. We use a stochastic model coming from stochastic geometry, and known as the dead leaves model. It intrinsically reproduces occlusions phenomena, producing edges at any scale and any orientation with a possibly low level of contrast. 

A method for evaluating texture quality as shot by a camera is presented. It is shown that usual sharpness measurements are not completely satisfying for this task. A new target based on random geometry is proposed. It uses the so-called dead leaves model. It contains objects of any size at any orientation and follows some […]

In this paper, we numerically quantify the information capacity of a sensor, by examining the different factors than can limit this capacity, namely sensor spectral response, noise, and sensor blur (due to fill factor, cross talk and diffraction, for given aperture). In particular, we compare the effectiveness of raw color space for different kinds of […]

This article explains the cause of the color fringing phenomenon that can be noticed in photographs, particularly on the edges of backlit objects. The nature of color fringing is optical, and particularly related to the difference of blur spots at different wavelengths. Therefore color fringing can be observed both in digital and silver halide photography.