Endoscopic single-image size measurements

2020 ◽  
Vol 31 (7) ◽  
pp. 074010
Author(s):  
George Dimas ◽  
Federico Bianchi ◽  
Dimitris K Iakovidis ◽  
Alexandros Karargyris ◽  
Gastone Ciuti ◽  
...  
Keyword(s):  
Image Size ◽  
Single Image

Hybrid Image Illusion

2017 ◽  
Author(s):  
Aude Oliva ◽  
Philippe G. Schyns
Keyword(s):  
Visual Illusions ◽  
Viewing Distance ◽  
Image Size ◽  
Single Image ◽  
Double Image ◽  
Spatial Frequencies ◽  
Dual Images

Artists, designers, photographers, and visual scientists are routinely looking for ways to create, out of a single image, the feeling that there is more to see than what meets the eye. Many well-known visual illusions are dual in nature, causing the viewer to experience two different interpretations of the same image. Hybrid images illustrate a double-image illusion, where different images are perceived depending on viewing distance, viewing duration, or image size: one that appears when the image is viewed up-close (displaying high spatial frequencies) and another that appears from afar (showing low spatial frequencies). This method can be used to create compelling dual images in which the observer experiences different percepts when interacting with the image.

scholarly journals Object Distance Estimation Using a Single Image Taken from a Moving Rolling Shutter Camera

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3860
Author(s):  
Namhoon Kim ◽  
Junsu Bae ◽  
Cheolhwan Kim ◽  
Soyeon Park ◽  
Hong-Gyoo Sohn
Keyword(s):  
Mathematical Model ◽  
Focal Length ◽  
Estimation Error ◽  
Distance Estimation ◽  
Estimation Methods ◽  
Image Size ◽  
Single Image ◽  
Object Distance ◽  
Camera Parameters ◽  
The Mathematical Model

This paper proposes a technique to estimate the distance between an object and a rolling shutter camera using a single image. The implementation of this technique uses the principle of the rolling shutter effect (RSE), a distortion within the rolling-shutter-type camera. The proposed technique has a mathematical strength compared to other single photo-based distance estimation methods that do not consider the geometric arrangement. The relationship between the distance and RSE angle was derived using the camera parameters (focal length, shutter speed, image size, etc.). Mathematical equations were derived for three different scenarios. The mathematical model was verified through experiments using a Nikon D750 and Nikkor 50 mm lens mounted on a car with varying speeds, object distances, and camera parameters. The results show that the mathematical model provides an accurate distance estimation of an object. The distance estimation error using the RSE due to the change in speed remained stable at approximately 10 cm. However, when the distance between the object and camera was more than 10 m, the estimated distance was sensitive to the RSE and the error increased dramatically.

Spherical Spaces for Illumination Invariant Face Relighting

2013 ◽  
Vol 25 (5) ◽  
pp. 840-847 ◽  
Author(s):  
Amr Almaddah ◽  
◽  
Sadi Vural ◽  
Yasushi Mae ◽  
Kenichi Ohara ◽  
...  
Keyword(s):  
Face Recognition ◽  
Processing Speed ◽  
Image Size ◽  
Single Image ◽  
Training Process ◽  
Real Time Processing ◽  
Lighting Conditions ◽  
Spherical Spaces ◽  
The Face ◽  
Face Albedo

In this paper, we propose a robust face relighting technique by using spherical space properties. The proposed method is done for reducing the illumination effects on face recognition. One single image is used as an input for recovering the face illumination and the recognition process. First, an internal training illumination database is generated by computing face albedo and face normal from 2D images under different lighting conditions. Based on the generated database, we analyze the target face pixels and compare them with the database by using pre-generated tiles. In this work, practical real time processing speed and small image size were considered when designing the framework. In contrast to other works, our technique requires no 3D face models for the training process and takes a single 2D image as an input. Experimental results on publicly available databases show that the proposed technique works well under severe illumination conditions and the method significantly improves the face recognition rates.

Sonography of subcutaneous tissue cannot determine causes of lower limb edema

VASA ◽  
2015 ◽  
Vol 44 (2) ◽  
pp. 122-128 ◽  
Author(s):  
Mandy Becker ◽  
Tom Schilling ◽  
Olga von Beckerath ◽  
Knut Kröger
Keyword(s):  
Clinical Diagnosis ◽  
Lower Limb ◽  
Subcutaneous Tissue ◽  
Hepatic Disease ◽  
Clinical Use ◽  
Single Image ◽  
Heart Insufficiency ◽  
Chronic Hepatic Disease ◽  
Limb Edema ◽  
Venous Disorders

Background: To clarify the clinical use of sonography for differentiation of edema we tried to answer the question whether a group of doctors can differentiate lymphedema from cardiac, hepatic or venous edema just by analysing sonographic images of the edema. Patients and methods: 38 (70 ± 12 years, 22 (58 %) females) patients with lower limb edema were recruited according the clinical diagnosis: 10 (26 %) lymphedema, 16 (42 %) heart insufficiency, 6 (16 %) venous disorders, 6 (16 %) chronic hepatic disease. Edema was depicted sonographically at the most affected leg in a standardised way at distal and proximal calf. 38 sets of images were anonymised and send to 5 experienced doctors. They were asked whether they can see criteria for lymphedema: 1. anechoic gaps, 2. horizontal gaps and 3. echoic rims. Results: Accepting an edema as lymphedema if only one doctor sees at least one of the three criteria for lymphatic edema on each single image all edema would be classified as lymphatic. Accepting lymphedema only if all doctors see at least one of the three criteria on the distal image of the same patient 80 % of the patients supposed to have lymphedema are classified as such, but also the majority of cardiac, venous and hepatic edema. Accepting lymphedema only if all doctors see all three criteria on the distal image of the same patients no edema would be classified as lymphatic. In addition we separated patients by Stemmers’ sign in those with positive and negative sign. The interpretation of the images was not different between both groups. Conclusions: Our analysis shows that it is not possible to differentiate lymphedema from other lower limb edema sonographically.

Single Image Dehazing by Predicting Atmospheric Scattering Parameters

2020 ◽  
Vol 2020 (1) ◽  
pp. 74-77
Author(s):  
Simone Bianco ◽  
Luigi Celona ◽  
Flavio Piccoli
Keyword(s):  
Reference Image ◽  
Single Image ◽  
Scattering Parameters ◽  
Image Dehazing ◽  
Atmospheric Scattering ◽  
Local Structures ◽  
Full Reference ◽  
Reconstruction Quality ◽  
Single Image Dehazing

In this work we propose a method for single image dehazing that exploits a physical model to recover the haze-free image by estimating the atmospheric scattering parameters. Cycle consistency is used to further improve the reconstruction quality of local structures and objects in the scene as well. Experimental results on four real and synthetic hazy image datasets show the effectiveness of the proposed method in terms of two commonly used full-reference image quality metrics.

Sign in / Sign up

Export Citation Format

Share Document