A salient image region is a part of the scene that stands out relative to neighboring regions. By that we mean that a human observer would experience a salient region as being more prominent. It is, however, important to quantify saliency in terms of a mathematical quantity that lends itself to measurements. Different metrics have been shown to correlate with human fixation data. These include contrast, brightness, and orienting gradients calculated at different image scales. In this paper, we show that saliency can be measured by the transformations pertaining to the dihedral group D₄, which is the symmetry group of the square image grid. Our results show that salient features can be defined as the image features that are most asymmetric in their surroundings.

It is well known that the volume of paste in halftones should be precisely controlled. In this work, a new method is proposed to calculate the volume of paste which includes halftone thickness and emulsion thickness. Moreover, the adhesion coefficients K₁ and K₂ in this new method can also be deduced from the experiment. In contrast with the conventional ideal method, the new method has more significant advantages. We find that the rheology has no influence on the adhesion coefficient in this new method. The results indicate that the new method can be used to calculate the volume of paste well when the emulsion thickness is below 20 μm. Therefore this new method is helpful in improving the production efficiency in the solar cell industry.

A two-roller-type printing fuser having a carbon nanotube resistance heater is proposed for reducing the warm-up time and reducing energy consumption. The paper non-contact region of the fuser overheats during a continuous printing job because the fuser generates a uniform heat flux over the whole fuser surface. Overheating causes melting of the fuser and roller sponge underneath. An island electrode design is added so that the electric conductivity increases and thus the heat generation can be controlled. With this design, the maximum temperature of the region is less than 210^°C during a continuous printing of 500 pages, while the fuser center temperature is controlled at 185^°C. We also performed an accelerated life testing and obtained a maximum temperature of less than 230^°C in the paper non-contact region without damage to the fusing belt.

Conversion from raw camera coordinates to a standard color space is developed here as a direct product of two independent maps, one for chromaticity coordinates of hue and saturation, the other for brightness. The principal focus is on the former. While the main approach is a target-based mapping, comparison with a more conventional approach shows that the structure of chromaticity for point reflection spectra at the capture gamut boundary influences the map far into the interior. Failure to account properly for this systematic effect is the largest source of error in standard color mappings. Restriction to chromatic mappings defines a class of corresponding chromatic metamers. Failure of a camera to satisfy the Luther condition produces two distinct classes of chromatic metamer errors: essential and adventitious.

Gloss and clarity are essential factors for image quality, and several measurement devices and methods have been proposed for evaluating gloss perception. However, a device that can simultaneously measure the subjective gloss and clarity of printed materials has not yet been developed. Currently, to evaluate gloss and clarity, it is necessary to use separate measuring devices. The purpose of this article is to report the development of a simple evaluation method solving this problem. First, the features of the reflectance distribution that contribute to the gloss and clarity were extracted using a goniophotometer. They can be explained using the glossiness (gloss values) at both 20^°and 60^° angles. Next, a simple evaluation method based on the ratio and the difference of the gloss values was developed. Results from the proposed method exhibited good correlation with subjective evaluation scores. Because of its simplicity, the proposed method is expected to find widespread use in the printing industry.

In this article, we report on a rapid infrared imaging method to measure the thickness and uniformity of water-dilutable two-dimensional macroscopic liquid objects. The method is based on the near-infrared absorption of water at 1440 nm or 1930 nm wavelength. As an example, the method is applied for nondestructive inspection of the thickness and uniformity of polyvinyl (PV)-based polyvinyl alcohol (PVA) and polyvinyl acetate (PVAc) adhesives, which are used in wood products. The method was also found to be able to observe the drying process of the adhesives.