List of Articles روشنایی

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  1 - Improvement of the Sharpness and Brightness of Dim Images Using the Retinax Approach and Nonlinear Conversion
  maryam ghasemi Morteza Khademi Abbas Ebrahimi moghadam
  Images captured in low light conditions are unsuitable for human and machine vision due to low brightness and sharpness and high noise, and have a negative effect on their performance. Much research has been done to improve such images. The methods proposed so far to so More

  Images captured in low light conditions are unsuitable for human and machine vision due to low brightness and sharpness and high noise, and have a negative effect on their performance. Much research has been done to improve such images. The methods proposed so far to solve this problem greatly improve such images. One of these methods is the RETINEX-based method, which modifies low-light images, but because the initial structure of this method is complex and inefficient, researchers have developed other methods such as SSR, MSR, and MSRCR. To solve the problem, they have presented this approach. These methods, in turn, have problems such as abnormal images and amplification of noise. In the continuation of the work done, the field of optimization has been used, which shows better performance than the previous works. In this research, by obtaining the optimal brightness component, using nonlinear conversion and applying smoothing filter and reducing noise on the image as a post-processing step, these weaknesses are largely eliminated. By applying the proposed method, the resulting images look more natural and their information is more preserved. Subjective and objective criteria such as EI, SSIM, PSNR and IMMSE were used to evaluate the proposed method. The simulation results show the superiority of the proposed method over the competing methods. Manuscript profile
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  2 - The Effect of Geometry and Light-receiving Surface on the Daylight Characteristics of the Room in Residential Architecture of Qajar Period (Case Study of Traditional Houses Located in Oudlajan Neighborhood of Tehran)
  ali hashemi MohammadReza Bemanian
  The problem Statement: Despite various estimates that have been made about the effective strategies in creating natural light and visual comfort in the structure of traditional Iranian houses, a precise quantitative evaluation of their efficiency and quality has not bee More

  The problem Statement: Despite various estimates that have been made about the effective strategies in creating natural light and visual comfort in the structure of traditional Iranian houses, a precise quantitative evaluation of their efficiency and quality has not been determined. Main question: What strategies were used in Qajar architecture to make the most use of natural daylight and how much was this important in traditional residential buildings of Tehran city due to the fluctuation of radiation intensity and the possibility of glare? Objective: This research aims to investigate and identify the effective strategies on the desirability of benefiting from natural daylight and visual comfort in traditional houses of Qajar period in Oudlajan neighborhood of Tehran. Research method: The present paper is based on a quantitative paradigm and a simulation strategy that uses Rhino software and evidence derived from reading the physical structure of traditional houses of Tehran city in Qajar period by non-random sampling for its calculations. Conclusion: The results showed that the daylight autonomy of the space in the majority of the rooms under study was at an acceptable level (more than 50%) and therefore these rooms were well lit by natural light. In addition, the comparison of the data of these analyses shows that the ratio used in the light-receiving surfaces was about 19.20% of the floor area of the room and the dominant direction of the light-receiving was from the south front. Also, all the rooms are in the acceptable level of glare probability mentioned in the lighting standards. Manuscript profile
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  3 - The role of the orientation of Isfahan houses in the natural lighting of spaces adjacent to the central courtyard: Historical houses of Isfahan city.
  ساناز  رهروی پوده
  <p>One of the influential factors in building design is their proper orientation regarding the placement of the sun and the optimal utilization of natural light. Research conducted on buildings constructed in Iran has referred to three orientations (directions): the ori More

  <p>One of the influential factors in building design is their proper orientation regarding the placement of the sun and the optimal utilization of natural light. Research conducted on buildings constructed in Iran has referred to three orientations (directions): the orientation of urban buildings relative to sunlight, wind direction, and generally the appropriate use of optimal climatic conditions. This article aims to investigate the orientation of courtyard houses in the city of Isfahan, built during the Safavid and Qajar periods, and its impact on the illumination of facades and spaces situated in each direction. The main research question is based on the orientation of houses, both in terms of direction and angle, and how it has affected the illumination of facades and consequently the spaces. The purpose of this research is to study the role of the orientation of houses in the illumination of spaces. The method employed in this study is qualitative research, and data collection utilized both library and field methods, with data analysis conducted using descriptive methods. The results of this research indicate that the orientation of houses on a north-south axis in winter, based on the Isfahan pattern, performs better than other angles for Tehran-style illumination (winter-oriented). However, overall, none of the orientations had a significant impact on facade illumination. Nonetheless, the varied placement angles in historical houses not built according to the Isfahan pattern were not climate-dependent but rather created based on the shape of the land and its axial alignment.</p> Manuscript profile