Comparing numerical error and visual quality in reconstructions from compressed digital holograms

Digital holography is a well-known technique for both sensing and displaying real-world three-dimensional objects. Compression of digital holograms has been studied extensively, and the errors introduced by lossy compression are routinely evaluated in a reconstruction domain. Mean-square error predominates in the evaluation of reconstruction quality. However, it is not known how well this metric corresponds to what a viewer would regard as perceived error, nor how consistently it functions across different holograms and different viewers. In this study, we evaluate how each of seventeen viewers compared the visual quality of compressed and uncompressed holograms' reconstructions. Holograms from five different three-dimensional objects were used in the study, captured using a phase-shift digital holography setup. We applied two different lossy compression techniques to the complex-valued hologram pixels: uniform quantization, and removal and quantization of the Fourier coefficients, and used seven different compression levels with each

Visual perception of digital holograms on autostereoscopic displays

In digital holography we often capture optically a 3D scene and reconstruct the perspectives numerically. The reconstructions are routinely in the form of a 2D image slice, an extended focus image, or a depth map from a single perspective. These are fundamentally 2D (or at most 2.5D) representations and for some scenes are not certain to give the human viewer a clear perception of the 3D features encoded in the hologram (occlusions are not overcome, for example). As an intermediate measure towards a full-field optoelectronic display device, we propose to digitally process the holograms to allow them to be displayed on conventional autostereoscopic displays

Vuorovaikutus monitieteisessä tutkimus- ja kehitysyhteistyössä

InnoGIS-hankkeessa maakunnan keskeiset tutkimus- ja koulutusorganisaatiot toteuttavat monitieteistä ja vuorovaikutteista tutkimus- ja kehitysyhteistyötä tavoitteenaan kehittää uusia paikkatietoratkaisuja ja -palveluita maakunnan tarpeisiin. Hankkeeseen perustetun monitieteisen tutkimusryhmän jäsenet osallistuvat oman kehittämistehtävänsä ohella hankkeen muiden kehittämistehtävien toteutukseen, millä pyritään hyödyntämään laajemmin jäsenten erikoisosaamista ja verkostoja sekä aktivoimaan työskentelyn vuorovaikutteisuutta. Tiimin toimintatavat ja yhteinen päämäärä on koettu selkeäksi ja yhteistyö on käynnistynyt hyvin. Tietämys yksittäisten kehittämistehtävien sisällöstä ja muiden asiantuntijuuden hyödyntäminen omassa kehittämistehtävässä on koettu suurimmaksi haasteeksi. Tehtävien välinen integrointi konkreettiselle tasolle ja yhteiset tuotokset jäsentyvät hankkeen edetessä. Ulkopuolisten asiantuntijoiden hyödyntäminen on hankkeen alkuvaiheessa ollut tapauskohtaista ja osalla aika vähäistä. Tiimin kommunikoinnissa testatut sosiaalisen median työkalut, Optima-verkkoympäristö sekä Skype ja ACP (Acrobat Connect Pro) kokoontumiset, on koettu toimiviksi ryhmän sisäisessä viestinnässä ja tiedon kulussa. Virtuaalisen kommunikoinnin lisäksi face-to-face –tapaamiset ovat välttämättömiä ryhmäytymisen ja yhteistyön toimivuuden kannalta. Yhteistyön tiivistämiseksi ja tietämyksen lisäämiseksi ryhmän jäseniä aktivoidaan materiaalin laajempaan jakamiseen Optima-verkkoympäristössä. Kehittämistehtäväkohtaisten Skype-istuntojen käynnistämisellä selkeytetään tehtävien sisältöjä, jotta ryhmän sisäinen asiantuntijuus saadaan tehokkaammin käyttöön

Visual perception of digital holograms on autostereoscopic displays

In digital holography we often capture optically a 3D scene and reconstruct the perspectives numerically. The reconstructions are routinely in the form of a 2D image slice, an extended focus image, or a depth map from a single perspective. These are fundamentally 2D (or at most 2.5D) representations and for some scenes are not certain to give the human viewer a clear perception of the 3D features encoded in the hologram (occlusions are not overcome, for example). As an intermediate measure towards a full-field optoelectronic display device, we propose to digitally process the holograms to allow them to be displayed on conventional autostereoscopic displays

Visual perception of digital holograms on autostereoscopic displays

In digital holography we often capture optically a 3D scene and reconstruct the perspectives numerically. The reconstructions are routinely in the form of a 2D image slice, an extended focus image, or a depth map from a single perspective. These are fundamentally 2D (or at most 2.5D) representations and for some scenes are not certain to give the human viewer a clear perception of the 3D features encoded in the hologram (occlusions are not overcome, for example). As an intermediate measure towards a full-field optoelectronic display device, we propose to digitally process the holograms to allow them to be displayed on conventional autostereoscopic displays

Comparing numerical error and visual quality in reconstructions from compressed digital holograms

Digital holography is a well-known technique for both sensing and displaying real-world three-dimensional objects. Compression of digital holograms has been studied extensively, and the errors introduced by lossy compression are routinely evaluated in a reconstruction domain. Mean-square error predominates in the evaluation of reconstruction quality. However, it is not known how well this metric corresponds to what a viewer would regard as perceived error, nor how consistently it functions across different holograms and different viewers. In this study, we evaluate how each of seventeen viewers compared the visual quality of compressed and uncompressed holograms' reconstructions. Holograms from five different three-dimensional objects were used in the study, captured using a phase-shift digital holography setup. We applied two different lossy compression techniques to the complex-valued hologram pixels: uniform quantization, and removal and quantization of the Fourier coefficients, and used seven different compression levels with each

Stereo perception of reconstructions of digital holograms of real-world objects

In digital holography a 3D scene is captured optically and often the perspectives are reconstructed numerically. In this study we digitally process the holograms to allow them to be displayed on autostereoscopic displays. This study is conducted by subjective visual perception experiments comparing single reconstructed images from left and right perspective to the resulting stereo image

Comparing numerical error and visual quality in reconstructions from compressed digital holograms

Digital holography is a well-known technique for both sensing and displaying real-world three-dimensional objects. Compression of digital holograms has been studied extensively, and the errors introduced by lossy compression are routinely evaluated in a reconstruction domain. Mean-square error predominates in the evaluation of reconstruction quality. However, it is not known how well this metric corresponds to what a viewer would regard as perceived error, nor how consistently it functions across different holograms and different viewers. In this study, we evaluate how each of seventeen viewers compared the visual quality of compressed and uncompressed holograms' reconstructions. Holograms from five different three-dimensional objects were used in the study, captured using a phase-shift digital holography setup. We applied two different lossy compression techniques to the complex-valued hologram pixels: uniform quantization, and removal and quantization of the Fourier coefficients, and used seven different compression levels with each

Comparing numerical error and visual quality in reconstructions from compressed digital holograms

Digital holography is a well-known technique for both sensing and displaying real-world three-dimensional objects. Compression of digital holograms has been studied extensively, and the errors introduced by lossy compression are routinely evaluated in a reconstruction domain. Mean-square error predominates in the evaluation of reconstruction quality. However, it is not known how well this metric corresponds to what a viewer would regard as perceived error, nor how consistently it functions across different holograms and different viewers. In this study, we evaluate how each of seventeen viewers compared the visual quality of compressed and uncompressed holograms' reconstructions. Holograms from five different three-dimensional objects were used in the study, captured using a phase-shift digital holography setup. We applied two different lossy compression techniques to the complex-valued hologram pixels: uniform quantization, and removal and quantization of the Fourier coefficients, and used seven different compression levels with each

Visual perception of digital holograms on autostereoscopic displays

In digital holography we often capture optically a 3D scene and reconstruct the perspectives numerically. The reconstructions are routinely in the form of a 2D image slice, an extended focus image, or a depth map from a single perspective. These are fundamentally 2D (or at most 2.5D) representations and for some scenes are not certain to give the human viewer a clear perception of the 3D features encoded in the hologram (occlusions are not overcome, for example). As an intermediate measure towards a full-field optoelectronic display device, we propose to digitally process the holograms to allow them to be displayed on conventional autostereoscopic displays