Qinghe Song

Real-time three-sensitivity measurements based on three-color digital Fresnel holographic interferometry

This Letter presents a method for real-time 3D measurements based on three-color digital holographic interferometry. The optical setup is considerably simplified, since the reference beams are combined into a unique beam. A convolution algorithm allows the three monochrome images to be superposed to provide simultaneous full-field 3D measurements. Experimental results confirm the suitability of the proposed method.

Digital holographic reconstruction of a local object field using an adjustable magnification

In the research of digital holography, this paper presents a numerical method using an adjustable magnification for local object field reconstruction together with experiment verification. The method first designs a spherical wave according to the given magnification to illuminate the digital hologram, then through a Fourier transform of diffraction, it calculates the reconstructed image plane. Afterward, a filtering window is set in the image plane to extract the image of the local object field, and then the object field reached hologram plane is formed using diffractions inverse operation. Finally, the object field is reconstructed through diffractions angular spectrum theory.

Nonlinear phenomena in digital holography: the case of pixel saturation

This paper proposes a theoretical and experimental analysis of the saturation effect in digital Fresnel holography and generalizes the linear image formulation to the case of the non linear pixel saturation.

Research on the recording hologram with Foveon in digital color holography

This letter presents a method for real-time three-color digital holographic interferometry based on Foveon CCD. The control mode of CCD is optimized and color aliasing is limited consumedly. The influence on color hologram becomes very little. On the whole, color aliasing is eliminated especially in the phase difference detecting. Moreover, the optical setup is considerably simplified, since the reference beams are combined into a unique beam. Experimental results confirm the suitability of the proposed method.

Eliminating zero-order diffraction in the digital holography wavefront reconstruction with adjustable magnification

The method of digital holography wavefront reconstruction with adjustable magnification is introduced. Since there is strong zero-order diffraction interference on the reconstruction plane, three different methods are proposed to eliminate zero-order diffraction interference, and compared through experiment. The experimental results demonstrated that the mean subtracted from a hologram is an effective method.

A simple and efficient algorithm to reconstruct digital color holograms

This paper presents a reconstruction algorithm based on an intermediate digital hologram which leads to the reconstruction of the image of the object with a controlled sampling pitch and number of pixels. The final image is obtained by calculating the diffraction from the intermediate hologram plane to the image plane using the convolution approach. Experimental results confirm the suitability of the proposed method. The calculation time is slightly better than the other similar approaches. Application in digital color holographic imaging shows that the proposed algorithm provides full color images of colored objects.

Digital color holographic reconstruction based on a virtual digital hologram

This paper presents a reconstruction algorithm based on an intermediate virtual digital hologram that can reconstruct color images with a controlled sampling pitch and pixel number. Experimental results confirm the suitability of the proposed method.

Influence of Pixel Saturation in Digital Holography

This paper proposes a theoretical and experimental analysis of the saturation effect in digital Fresnel holography and generalizes the linear image formulation to the case of the non linear pixel saturation.

Real-Time 3D Sensing Using a Stacked Color Image Sensor

We present real-time three-dimensional sensing based on digital three color holography. The colors are simultaneously recorded by a stacked image sensor and an algorithm with adjustable magnification provides real time full field 3D measurements.

A sample test on the tilt angle of object light illumination in the digital holographic 3D surface shape detection

This paper discussed the measurement error of digital holographic 3D surface shape caused by imprecise measurement of the incident angle and the tilt angle of object light illumination in theory. The result showed that the error caused by the tilt angle is much greater than the incident angle. Then a method to accurately calculate the object lights tilt angle by detecting the interference field of reference plane is proposed based on the above discussion. Finally, the feasibility of the method is proved through a 3D surface shape detection experiment.