Nikola Mrvac

The Effect of Expansion and Simultaneous Contrast in Modificated Figural Dotted and Groundal Dotted Illusions

The appearance of colour is based on different parameters and observation conditions. Taking into account that the research of certain visual psychophysical effects is updated daily, such a phenomenon presents a challenge for researchers of modern visual communication systems. Effects of psychophysical expansion and simultaneous contrast belong to this group. This paper researches the influence of those effects using method of visual tuning. Those effects cause the shifting of colour appearance of stimuli (different combinations of primary and secondary colours) on test samples. Test samples are based on White’s illusions (groundal dotted illusion and figural dotted illusion).

Influence of Computer Clipboard Transfer of Image Data on Print Quality Perception and Measurement

In today’s virtual environment transfer of data within the system is a necessary and standard operation. Computer clipboard is one of the common data transfer methods. This paper tests the changes in image data during the transfer from one program to another. Computer programs and systems use different standards, which causes changes in colour values due to different image standards used by programs and systems. Each transfer between programs causes adaptation of image data to new program standards. That shift is visible on images from inside the system. The difference grows even more on the printed sample. Calibration strip and photographs were used as research elements. Calibration strip was generated in Monaco Profiler. The analysis was performed on measured numerical values, and it showed significant colour changes in samples. The visual research was made on printed photo samples and has shown that the visibility of colour changes more or less depends on the motif type.

The intensity of the background visual effect of crispening depending on background lightness

The paper presents the results of a research of the background visual effect of crispening depending on background lightness. An research on graphic reproductions with specifically designed solutions that involve the mentioned effect was conducted. Reproductions were designed through the variations of four different types of background lightness of 25%, 50%, 75% and 100% RTV (secondary stimuli), on which there are internal rectangles of lightness of 45%, 50% and 55% RTV (primary stimuli). The visual experiment was carried out through the use of the technique of simultaneous binocular harmonization with a 10 respondents. The ANOVA with repeated measures revealed statistically differences between the arithmetic means of variations in lightness for four variations of the background in all three primary stimuli. Further post-hoc analysis by Fisher identified the groups that mutually differ. The results indicate the regularities to which the effect of crispening is subjected in the selected graphic medium.

THE INFLUENCE OF THE THICKNESS OF THE GRID IN MUNKER-WHITE EFFECT

This paper shows the influence of the thickness of the grid on the intensity and assimilation in Munker-White effect. It can be described as the effect of assimilation of grey rectangular elements into the colour of unbroken lines. They are perceived darker in combination with grey and black lines, and lighter in white and grey combination. Measured colorimetric differences are shown in CIEDE2000 system. Three polynomial statistical regression models were created based on the results. Models contain polynomial expressions describing the influence of the grid thickness on the intensity shift of rectangular objects in Munker-White effect. Models were tested statistically and the analysis of measured parameters shows their statistical

Determination of visual interest points of graphical user interfaces for tablet newspapers application

In this paper the authors determine the visual interest centres and the points of visual entry of observers on the page of graphical user interface for newspaper tablet application using the method of monitoring the eye movement. The research presented in this paper demonstrates that the key visual elements and points of entry in this case function in the same way as in the case of the printed edition of daily newspapers, and do not follow the patterns that occur in the application of content on websites of corresponding newspaper.

The influence of increasing the tone value on the printing reproduction quality

In graphic reproduction, because of the specific features of the process influenced by different parameters, deformities of the screen element happen influencing more or less the reproduction quality decrease at consumers during the observation of the graphic product in real conditions. This work investigates the influence of the tone values increase on the quality decrease of the printed graphic product.