• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.11
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• pp.4043-4064
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• 2021

Night-time image quality evaluation is an urgent requirement in visual inspection. The lighting environment of night-time results in low brightness, low contrast, loss of detailed information, and colour dissonance of image, which remains a daunting task of delicately evaluating the image quality at night. A new blind quality assessment metric is presented for realistic night-time scenario through a comprehensive consideration of contrast, texture, and colour in this article. To be specific, image blocks' color-gray-difference (CGD) histogram that represents contrast features is computed at first. Next, texture features that are measured by the mean subtracted contrast normalized (MSCN)-weighted local binary pattern (LBP) histogram are calculated. Then statistical features in Lαβ colour space are detected. Finally, the quality prediction model is conducted by the support vector regression (SVR) based on extracted contrast, texture, and colour features. Experiments conducted on NNID, CCRIQ, LIVE-CH, and CID2013 databases indicate that the proposed metric is superior to the compared BIQA metrics.

• Journal of Korea Multimedia Society
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• v.22 no.1
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• pp.44-54
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• 2019

Recently, image-based object detection has made great progress with the introduction of Convolutional Neural Network (CNN). Many trials such as Region-based CNN, Fast R-CNN, and Faster R-CNN, have been proposed for achieving better performance in object detection. YOLO has showed the best performance under consideration of both accuracy and computational complexity. However, these data-driven detection methods including YOLO have the fundamental problem is that they can not guarantee the good performance without a large number of training database. In this paper, we propose a data sampling method using CycleGAN to solve this problem, which can convert styles while retaining the characteristics of a given input image. We will generate the insufficient data samples for training more robust object detection without efforts of collecting more database. We make extensive experimental results using the day-time and night-time road images and we validate the proposed method can improve the object detection accuracy of the night-time without training night-time object databases, because we converts the day-time training images into the synthesized night-time images and we train the detection model with the real day-time images and the synthesized night-time images.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.3
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• pp.339-344
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• 2014

Purpose: This study relates to the development of the day and night scope using the reflecting surface of a BS (beam splitting) prism. Methods: We have placed the LCD panel and the dot reticle generator to the top and bottom of the reflecting surface of the BS prism, and have placed a reflector, which is designed to doublet type, in the front of the BS prism. Doing so, we have developed a new type of day and night scope, which is able to image the virtual image of dot reticle from the dot reticle generator to the direction of the observer, to make the observer survey the peripheral information of the outside target by 1x magnification, and to make the observer survey the image of the LCD panel directly. Results: We could develope a new type of day and night scope, which has the function of night scope as thermal image display device at night time and the function of day scope as dot sight at day time, by letting the reflective surface of the BS prism have the role of dot sight which reflects the dot reticle and have the role of reflective optical system by which the observer surveys the night thermal image displayed in LCD panel. Conclusions: In this study, we have developed the new type of day and night scope which is able to play the role of the day or night scope selectively, combining the existing dot sight and the existing night scope by using the BS prism. By doing so, we could design and fabricate the new type of day and night scope with the BS prism which can further increase the rapidity of firing and provide more convenience in the mounting of a firearm than the detachable combination of an existing dot sight and an existing night scope.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.58-61
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• 2000

In this paper, we describe an effective method to enhance the color night images with spatio-temporal multi-scale retinex focused to the Intelligent Transportation System (ITS) applications such as in the single CCD based Electronic Toll Collection System (ETCS). The basic spatial retinex is known to provide color constancy while effectively removing local shades. However, it is relatively ineffective in night vision enhancement. Our proposed method, STMSR, exploits the iterative time averaging of image sequences to suppress the noise in consideration of the moving vehicles in image frame. In the STMSR method, the spatial term makes the dark images distinguishable and preserves the color information day and night while the temporal term reduces the noise effect for sharper and clearer reconstruction of the contents in each image frame. We show through representative simulations that incorporating both terms in the modeling produces the output sequential images visually more pleasing than the original dim images.

• Korean Institute of Interior Design Journal
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• v.24 no.6
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• pp.137-144
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• 2015

Light was the symbol of the city's prosperity and culture. People can walk around the city at the night time with safe. Now light is used with beauty and function at the same time. This study is the example how to draw the lighting design concept in specific city and district based on the citizen-minded survey. The citizen-minded survey makes a new chance taking the goodness and characteristics from local city specially and select the site for applying the specific opinion and requirement in the city. The expression of design concept on night landscape design gives the fresh image to the city during the night time. Because people feel the free and dynamic mood in the night landscape lighting, it is very important to set and express the design concept on night landscape design. The result of this study was applied in the Daegu city. In particular, the distribution complex's night landscape lighting in the Daegu was designed with specific concept expression from the citizen-minded survey. Making and expressing the design concept on night landscape design is basic for unity and diversity in the city.

• Korean Journal of Remote Sensing
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• v.27 no.1
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• pp.69-74
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• 2011

It may be an important issue to estimate population of a concerned country. In this study, an appropriate variable was selected to establish a model which fits best the relationship between the night time imagery of DMSP-OLS and population data. Exponential model was selected which was proposed by previous study. Accuracy validation was also performed for each variable extracted from the night time imagery of DMSP-OLS. Consequently, the model showed high accuracy when applied to the area of a certain amount of light was existed. However, further consideration should be necessary when to applied other country or other part of regions.

• Journal of Korea Multimedia Society
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• v.20 no.12
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• pp.1901-1912
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• 2017

Traffic lights at night are usually framed in the image as bright regions bigger than the real size due to glow effect. Moreover, the colors of lighting region saturate to white. So it is difficult to distinguish between different traffic lights at night. Many related studies have tried to decrease the glow effect in the process of capturing images. Some studies drastically decreased the shutter time of the camera to reduce the adverse effect by the glow. However, this makes the video too dark. This study proposes a new idea which utilizes the glow effect. It examines the outer radial region of traffic light. It presents an algorithm to discriminate the color of traffic light by the analysis of the outer radial region. The advantage of the proposed method is that it can recognize traffic lights in the image captured by an ordinary black box camera. Experimental results using seven short videos show the performance of traffic light recognition reporting the precision of 96.4% and the recall of 98.2%. These results show that the proposed method is valid and effective.

• Journal of Korea Multimedia Society
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• v.18 no.3
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• pp.339-348
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• 2015

In this paper, we propose improved night visibility enhancement algorithm based on haze removal method. The proposed method uses new haze removal method in place of the conventional methods. Our night visibility enhancement method is very good and faster than traditional methods. This method also uses additionally local histogram equalization for sharpening the enhanced image. Our method can be applied to any application that uses a visible light camera, and it is appropriate to apply a black box, vehicle camera, and cell phone camera, since it is possible that real-time processing.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.135-136
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• 2017

When driving at night time environment, the whole body of transports does not visible to us. Due to lack of light conditions, there are only two options, which is clearly visible their taillights and break lights. To improve the recognition correctness of vehicle detection, we present an approach to vehicle detection and tracking using finding contour of the object on binary image at night time. Bilateral filtering is used to make more clearly on threshold part. To remove unexpected small noises used morphological opening. In verification stage, paired tail lights are tracked during their existence in the ROI. The accuracy of the test results for vehicle detection is about 93%.

• Journal of Korea Water Resources Association
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• v.48 no.8
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• pp.659-672
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• 2015

In flow velocity measurement of natural rivers, taking images with proper image quality is the fundamental and the most important step. Since flood peaks generally occur in night time, it is very difficult to capture proper images in that time. The present study aims to test a far infra-red camera as a adequate alternative to resolve the various problems in measuring flood discharges. The far infra-red cameras are able to capture images in night time without help of any extra illuminations. Futhermore they are not affected by fog nor smoke, hence they can be adapted for a fixed-type surface image velocimeters. For comparison, a commercial camcorder and a near infra-red cameras were used together. The test images were taken at a day time and a night time, and the image acquisition work were performed at an artificial flow channel of the Andong River Experiment Station. The analyzed results showed that the far infra-red camera would be a good instrument for surface image velocimeters, since they were able to capture regardless light condition. There are, however, a few minor problems in their accuracy of the analyzed results. About their accuracy a more study would be required.