• Title, Summary, Keyword: color variation

Search Result 703, Processing Time 0.036 seconds

Photographic Color Reproduction Based on Color Variation Characteristics of Digital Camera

  • Kim, Ui-Seong;Lee, Jong-Min;Kim, Yong-Min;Park, Ki-Tae;Moon, Young-Shik
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.5 no.11
    • /
    • pp.2160-2174
    • /
    • 2011
  • In this paper, a new technique for color reproduction based on color variation characteristics of digital camera under a dim light condition is proposed. Generally, photographers should adjust a camera exposure properly for obtaining an image with real color tone of subjects. Thus, in case of taking a picture under a dim light condition, the exposure time of a camera has to be relatively longer than the one under a bright light condition. Although images with real color tone of the subject are obtained, the images may get blurred due to the shaky hands of photographer holding the camera. In order to avoid the blur effect, an input image is captured from a camera set as a short exposure time under a dim light condition. Then we propose a method to reproduce color tone of the dim input image. To this end, color variation characteristics which represent color variations of a digital camera are first extracted by analyzing the Macbeth color checker images taken under various exposure values. Then, a color reproduction is performed by an estimation based on the color variation characteristics. Experimental results have shown that the proposed method has achieved better performance of color reproduction, compared with existing methods.

Color variation induced by abutments in the superior anterior maxilla: an in vitro study in the pig gingiva

  • Atash, Ramin;Boularbah, Mohamed-Reda;Sibel, Cetik
    • The Journal of Advanced Prosthodontics
    • /
    • v.8 no.6
    • /
    • pp.423-432
    • /
    • 2016
  • PURPOSE. The aim of this work is to evaluate different types of materials used for making implant abutments, by means of an in vitro study and a review of the literature, in order to identify the indications for a better choice of an implant-supported restoration in the anterior section. MATERIALS AND METHODS. 5 implant abutments were tested in a random order in the superior anterior maxilla of pig gingiva (n = 8): titanium dioxide (Nobel Biocare); zirconium dioxide, Standard BO shade (Nobel Biocare, Kloten, Switzerland); zirconium dioxide, Light BI shade (Nobel Biocare); zirconium dioxide, Intense A 3.5 shade (Nobel Biocare); and aluminium oxide. Each abutment was tested for 2 mm and 3 mm thickness. To determine color variation, VITA Easyshade Advance spectrophotometer (Vita Zahnfabrik, Bad Sackingen, Germany) was used. RESULTS. Results showed that the color variation induced by the abutment would be affected by the abutment material and gingival thickness, when the gingival thickness is 2 mm. All materials except zirconium dioxide (Standard shade) caused a visible change of color. Then, as the thickness of the gingiva increased to 3 mm, the color variation was attenuated in a significant manner and became invisible for all types of abutments, except those made of aluminium oxide. CONCLUSION. Zirconium dioxide is the material causing the lowest color variation at 2 mm and at 3 mm, whereas aluminium oxide causes the highest color variation no matter the thickness.

A Study on the Area Effect of Color by the Observing Distance and the Sight Angle (관찰거리와 시각에 따른 색채의 면적효과에 관한 연구)

  • Lee Jin-Sook;Yim Oh-Yon;Lee Deok-Hyung
    • Korean Institute of Interior Design Journal
    • /
    • v.15 no.4
    • /
    • pp.123-128
    • /
    • 2006
  • The purpose of the research is to estimate the amount of a color image reaction variation by changing areas in order to design the method to reduce an error about the color sample when it is applied in the real situation. The summary of the results acquired in this research is as followed. (1) With fixed observing distance of 1m, we observed that the value and chroma of each color object became higher as sight angle was increased as $2^{\circ},\;10^{\circ},\;and\;30^{\circ}$, even though the variation ratio was different. (2) With fixed sight angle of 10, we observed that the value and chroma of each color object becane higher as observing distance was changed from 1m to 3.3m, even though the variation ratio was different. (3) With same area, we observed that the values and chromas of each color object in the conditions of $1m-30^{\circ}\;and\;3.3m-10^{\circ}$ were almost same. (4) When the area became larger, the subjects tended to feel that colors were bright and clear with the increase of tone. In all the colors, the variation of a color reaction in chroma is higher than those in value. In future, we can observe the limit in applying to colors in the architecture by identifying the tendency of the color change according to the area change qualitatively.

Investigating the Color Differences of 90 ${\times}$ 90 mm Larch Squares Heat-treated at Various Temperatures (처리 온도에 따른 90 ${\times}$ 90 mm 낙엽송 각재의 재색 차이 조사)

  • Kang, Ho-Yang;Kang, Chun-Won
    • Journal of the Korea Furniture Society
    • /
    • v.22 no.4
    • /
    • pp.265-269
    • /
    • 2011
  • To make value-added products from small-diameter larch logs it is necessary to reduce the color variation between boards. The effect of heat treatment on the color variation was investigated. Four hundred air-dried larch squares were visually classified into six groups. The largest color difference index between them was 8.8. When they were kiln-dried lower than $120^{\circ}C$, their average color difference indexes decreased to less than 6.0 compared with the air-dried. However statistical analyses revealed that kiln-drying largely increased the variation of the indexes of the color elements. Heat-treatment above $150^{\circ}C$ increased the color difference indexes with the increase of temperature. The variation of color difference indexes within a group at $190^{\circ}C$ were less than the groups at $150^{\circ}C$ and $170^{\circ}C$. It implies that heat treatment at $190^{\circ}C$ could make the color of larch squares uniform.

  • PDF

Analysis of Color Combination with Value Variation on Signboards in Complex Commercial Facilities (복합상업시설 간판의 명도변화 색채구성 분석)

  • Chung, Jae-Hoon
    • Journal of the Architectural Institute of Korea Planning & Design
    • /
    • v.35 no.1
    • /
    • pp.83-92
    • /
    • 2019
  • Advertising signboards are designed for the visibility to affects recall and recognition of costumers. It is well know that the visibility from images is created by the value difference among colors. The research defines whether the background color combination of outdoor signboards is configured to maximize visibility, by a series of color value variation in complex commercial facilities. The subject of study is to examine how the visibility is made by the color combination since visibility cannot be obtained independently. Two steps of analysis were performed to confirm that the color composition of signboards was based on the color value difference. The first is to analyze that the entire colors of signboards are clearly categorized as different value groups. All components of colors, hue, value and chroma had been analyzed by color aesthetic measures to prove that the value variation has the only regularity and the principle of composition. The second step is a further verification with an ample amount of samples to determine whether series of signboards create a value altering pattern. The data for analysis is gained by colorimetric survey and the color data are used for exponentializing the degree of combining, which shows selective affinity between each pair colors.

Color Variation in Color-shade Polycrystalline Zirconia Ceramics by the Atmosphere Controlled Firing

  • Chang, Myung Chul
    • Journal of the Korean Ceramic Society
    • /
    • v.55 no.2
    • /
    • pp.116-125
    • /
    • 2018
  • Color shade variation was investigated in zirconia dental blocks, prepared using commercial powders. As a reference color-shade block we used the color indexes of A2, A3.5, A4 and B3, according to the VITA classical color scale. The zirconia powders for color shade blocks showed colors of white, yellow, pink and grey, respectively, after firing at $1530^{\circ}C$. The zirconia powders were mixed according to the recipe of color shade blocks and shaped at lower pressure using a uniaxial hydrostatic press. The shaped sample was inserted into a vinyl pack and sealed in a vacuum form machine. The shaped block samples were reshaped at 450 bar using an isostatic cold press and fired at $1530^{\circ}C$ for three hours. In order to investigate the atmospheric color variation with firing temperature, the A2, A3.5, A4 and B3 sintered blocks were fired between $700^{\circ}C$ and $1300^{\circ}C$ under controlled atmosphere of $pN_2$ and $pO_2$. The surface color picture was taken using a smart phone camera and compared with the results obtained using the VITA classical color scale. Quantitative color index value, CIELAB, was measured using a color-meter. Above $800^{\circ}C$, the color darkness greatly increased with the increase of the reduction temperature and keeping time.

A Cross-cultural Study on the Affection of Color with Variation of Tone and Chroma for Automotive Visual Display

  • Jung, Jinsung;Park, Jaekyu;Choe, Jaeho;Jung, Eui S.
    • Journal of the Ergonomics Society of Korea
    • /
    • v.36 no.2
    • /
    • pp.123-144
    • /
    • 2017
  • Objective: The objective of this study is to evaluate affection on how users perceive colors viewed from an automotive visual display according to cultural and radical differences including North America, Europe, and Southeast Asia. This study especially aims to identify effects of the variation of tone and chroma of representative color groups by analyzing affection differences depending on cultural and racial differences targeting the colors constituted through variation of tone and chroma, centered on representative colors. Background: The colors of the menu, information display or background viewed through an automotive visual display are an important factor stimulating consumer's affection, and therefore an effort to express the vehicle's brand and product image through colors is made. The studies on colors focus only on the research on unique characteristics of colors, but an affective approach lacks according to cultural and racial differences on colors considering tone and chroma variation within a color from the currently used automotive visual displays. Method: To grasp the visual affection felt by users, this study extracted affective adjectives related with colors through existing literature and a dictionary for adjectives, and presented human affection dimensions on colors through evaluation of various colors. Prior to carrying out affection evaluation, the basic light sources, red (R), green (G), and blue (B) constituting the colors used for automotive visual displays were defined as a representative color group, respectively. When colors in a color group are constituted, the evaluation target of each color group consisted of the colors considering the variation of tone and chroma by changing color sense through RGB values of the remaining two light sources. And then, this study carried out affection evaluation on the constituted colors targeting the subjects with cultural and racial differences. Results: As a result of evaluating the constituted colors with representative affections, there were statistically significant differences between the groups having cultural and racial differences. As a result of S-N-K post-hoc analysis on the colors showing significant differences, North America and Europe were classified as heterogeneous groups. In some cases, Korea was classified as the homogeneous group with North America, but Korea was mainly classified as the homogenous group with Europe. Conclusion: The representative affections on colors from an automotive visual display was drawn as three affective dimensions: passionate, neat, and masculine. Based on these, the affection of Korea and Europe on the constituted colors showed significant differences from that of North America, as a result of affection evaluation on the constituted colors viewed through the visual display by reflecting cultural and racial factors. Regarding representative color groups, bigger cultural and racial differences were revealed in terms of affection on red and green colors than on blue color, and variation of affection was the biggest in the red color. Application: This study analyzed correlations of affection considering the colors constituted through variation of tone and chroma, and the culture and race in the representative color groups constituting a visual display. The results of this study are predicted to be utilized in coordination and selection of colors viewed from an automotive visual display taking into account culture and race.

Temporal Color Rolling Suppression Algorithm Considering Time-varying Illuminant (조도 변화를 고려한 동영상 색 유동성 저감 알고리즘)

  • Oh, Hyun-Mook;Kang, Moon-Gi
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.48 no.5
    • /
    • pp.55-62
    • /
    • 2011
  • In this paper, a temporal color and luminance variation suppression algorithm for a digital video sequence is proposed by considering time-varying light source. When a video sequence is sampled with the periodically emitting illuminant and with a short exposure time, the color rolling phenomenon occurs, where the color and the luminance of the image periodically change from field to field. In conventional signal processing techniques, the luminance variation remaining in the resultant video sequence degrades the constancy of the image sequence. In the proposed method, we obtain video sequences with constant luminance and color by compensating for the inter-field luminance variation. Based on a motion detection technique, the amount of the luminance variation for each channel is estimated on the background of the sequence without the effects of moving objects. The experimental results clearly show that our strategy efficiently estimated the illuminant change without being affected by moving objects, and the variations were efficiently reduced.

Color Quality Evaluation of High Color Rendering White LEDs According to Phosphor Types and Composition Ratio (형광체 종류와 조성비에 따른 고연색 백색 LED의 색품질 평가)

  • Jeong, Hee Suk;Ryeom, Jeongduk
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.30 no.7
    • /
    • pp.463-468
    • /
    • 2017
  • Eight types of LED packages were manufactured according to the type and composition ratio of phosphors by using commercially available white LED phosphors. CRI (Ra), a conventional color quality evaluation method was evaluated by using manufactured white LED; the Rf, Rg, color vector graphic, and color distortion graphic were evaluated with a new method, IES TM-30-15. The results of the evaluation confirmed that the new method compensated for the disadvantages of CRI, which was found to be inadequate when the color was saturated. The added evaluation index identified the chroma variation and color change. Furthermore, the study showed that the changes of Rf and Rg are small when controlling phosphors based on CRI, questioningthe necessity of identifyingchroma variation and color change.

On the Variation in Color and Pattern of Grphosoma rubrolineatum WESTWOOD (홍줄노린재의 체색 및 반문의 변이에 관하여)

  • 윤일병
    • The Korean Journal of Zoology
    • /
    • v.8 no.2
    • /
    • pp.51-54
    • /
    • 1965
  • Present author observed the variation in color and pattern and also those of geographical distribution of Graphosoma rubrolineatum WESTWOOD.And the variations were also studied in relation to the temperature and the humidity . The results are as follows . 1. The variations in color and pattern of G.rubrolineatum were gradually changed into black ones, and so they showed polymorphic. 2. Their colors and patterns were not variated in inland at all, while those variations in island increased according to the distance from the inland. 3. The red color of the patterns appeared the yellowish-red in inland, the blackish -red in island. 4. The variation in color and pattern of G.rubrolineatum occure in the region of the temperature below 22.8$^{\circ}C$ (mean temperaturrre of June, July and August)and the humidity above 72%(yearly average).

  • PDF