Non-destructive forensic latent fingerprint acquisition with chromatic white light sensors

Benchmarking contact-less surface measurement devices for fingerprint acquisition in forensic investigations: Results for a differential scan approach with a chromatic white light sensor

“…To assess whether a sensor is capable of acquiring fingerprint traces from a given surface, we suggest the differential image quality measure for both, the intensity and topography dataset, as preliminarily investigated in [1] and [2]. This known technique is applied to serve as an optimal case for the crime scene investigation and to visualize what might be seen within a scan result using optimal pre-processing algorithms.…”

“…We scanned 18 unique samples once and a sheet of copying paper as additional real-world object at two different stages of fingerprint residue absorption, resulting in 20 samples in total. In addition to the subjective assessment of the results from [1] and [2] we use the entropy, mean and standard deviation as first statistical measures towards the detectability of the fingerprint traces within the acquired data. First results show, that the differential quality measure is suitable for assessing the general adequacy of a sensor for latent fingerprint scanners for the majority of surfaces.…”

“…This paper concludes with an exemplary evaluation of a CWL sensor according to the differential image property in Section 4. Compared to [1] and [2], with experimental setups consisting of 10 and 6 surfaces, respectively, we use an extended set of 12 sample materials and 8 real-world objects, which might be relevant for forensic investigations. We scanned 18 unique samples once and a sheet of copying paper as additional real-world object at two different stages of fingerprint residue absorption, resulting in 20 samples in total.…”

Approximation of a Mathematical Aging Function for Latent Fingerprint Traces Based on First Experiments Using a Chromatic White Light (CWL) Sensor and the Binary Pixel Aging Feature

“…For our research, so far only the intensity images produced by the sensor are of interest, leaving the use of topographical values for future work. Potential other contactless sensors are summarised in [1]. best of our knowledge, most natural processes have a logarithmic, exponential or (in some cases) linear course.…”

“…Only very limited results have been achieved in this field so far. In recent years, contactless scanning techniques have been introduced to the field of fingerprint forensic research, often adapting surface-or other purpose measurement devices for the non-invasive acquisition of latent fingerprint traces (see [1] for a summary of such techniques). These acquisition techniques offer new opportunities to the field of fingerprint age determination, since latent fingerprint traces can now be obtained with a very high resolution and accuracy (which could not fully be achieved by classical powdering and sticky tape lifting or fuming with cyanoacrylate or other development techniques and subsequent photographing).…”