Compact Texture Research Articles

INLINING 3D RECONSTRUCTION, MULTI-SOURCE TEXTURE MAPPING AND SEMANTIC ANALYSIS USING OBLIQUE AERIAL IMAGERY

This paper proposes an in-line method for the simplified reconstruction of city buildings from nadir and oblique aerial images that at the same time are being used for multi-source texture mapping with minimal resampling. Further, the resulting unrectified texture atlases are analyzed for fac¸ade elements like windows to be reintegrated into the original 3D models. Tests on real-world data of Heligoland/ Germany comprising more than 800 buildings exposed a median positional deviation of 0.31 m at the fac¸ades compared to the cadastral map, a correctness of 67% for the detected windows and good visual quality when being rendered with GPU-based perspective correction. As part of the process building reconstruction takes the oriented input images and transforms them into dense point clouds by semi-global matching (SGM). The point sets undergo local RANSAC-based regression and topology analysis to detect adjacent planar surfaces and determine their semantics. Based on this information the roof, wall and ground surfaces found get intersected and limited in their extension to form a closed 3D building hull. For texture mapping the hull polygons are projected into each possible input bitmap to find suitable color sources regarding the coverage and resolution. Occlusions are detected by ray-casting a full-scale digital surface model (DSM) of the scene and stored in pixel-precise visibility maps. These maps are used to derive overlap statistics and radiometric adjustment coefficients to be applied when the visible image parts for each building polygon are being copied into a compact texture atlas without resampling whenever possible. The atlas bitmap is passed to a commercial object-based image analysis (OBIA) tool running a custom rule set to identify windows on the contained fac¸ade patches. Following multi-resolution segmentation and classification based on brightness and contrast differences potential window objects are evaluated against geometric constraints and conditionally grown, fused and filtered morphologically. The output polygons are vectorized and reintegrated into the previously reconstructed buildings by sparsely ray-tracing their vertices. Finally the enhanced 3D models get stored as textured geometry for visualization and semantically annotated ”LOD-2.5” CityGML objects for GIS applications.

INLINING 3D RECONSTRUCTION, MULTI-SOURCE TEXTURE MAPPING AND SEMANTIC ANALYSIS USING OBLIQUE AERIAL IMAGERY

Abstract. This paper proposes an in-line method for the simplified reconstruction of city buildings from nadir and oblique aerial images that at the same time are being used for multi-source texture mapping with minimal resampling. Further, the resulting unrectified texture atlases are analyzed for fac¸ade elements like windows to be reintegrated into the original 3D models. Tests on real-world data of Heligoland/ Germany comprising more than 800 buildings exposed a median positional deviation of 0.31 m at the fac¸ades compared to the cadastral map, a correctness of 67% for the detected windows and good visual quality when being rendered with GPU-based perspective correction. As part of the process building reconstruction takes the oriented input images and transforms them into dense point clouds by semi-global matching (SGM). The point sets undergo local RANSAC-based regression and topology analysis to detect adjacent planar surfaces and determine their semantics. Based on this information the roof, wall and ground surfaces found get intersected and limited in their extension to form a closed 3D building hull. For texture mapping the hull polygons are projected into each possible input bitmap to find suitable color sources regarding the coverage and resolution. Occlusions are detected by ray-casting a full-scale digital surface model (DSM) of the scene and stored in pixel-precise visibility maps. These maps are used to derive overlap statistics and radiometric adjustment coefficients to be applied when the visible image parts for each building polygon are being copied into a compact texture atlas without resampling whenever possible. The atlas bitmap is passed to a commercial object-based image analysis (OBIA) tool running a custom rule set to identify windows on the contained fac¸ade patches. Following multi-resolution segmentation and classification based on brightness and contrast differences potential window objects are evaluated against geometric constraints and conditionally grown, fused and filtered morphologically. The output polygons are vectorized and reintegrated into the previously reconstructed buildings by sparsely ray-tracing their vertices. Finally the enhanced 3D models get stored as textured geometry for visualization and semantically annotated ”LOD-2.5” CityGML objects for GIS applications.

FREE CHOICE PROFILING, ACCEPTANCE AND PURCHASE INTENTION IN THE EVALUATION OF DIFFERENT BISCUIT FORMULATIONS

ABSTRACT The increased demand for differentiated and health-oriented food has driven the development of bakery products with specific nutritional and sensory characteristics. The aim of this study was to compare four different biscuits: two commercial (sugar-free and gluten-free) and two experimental formulations (standard and source of extra fiber). The cookie with added fiber had passion fruit albedo and pumpkin peel added to its formulation, as well as reduced wheat flour content compared with the standard formulation. These alterations aimed to achieve both nutritional and economic benefits. The Free Choice Profiling methodology was used, and the data were subjected to Generalized Procrustes Analysis. The analysis was performed separately by attribute classes (appearance, aroma, flavor and texture). The percentage of variance explained in the first dimension was 87.6% for texture, and the sum of the first two dimensions was greater than 90% for all four attributes. Both experimental formulations were characterized as having a yellowish color, flattened appearance, passion fruit aroma, natural aroma, passion fruit flavor, passion fruit residual flavor, soft texture and compact texture. Therefore, the addition of byproducts in the standard formulation did not qualitatively change the characteristic attributes. The products were also evaluated on a 9-point hedonic scale, and the data were statistically evaluated by analysis of variance (ANOVA). When compared by affective analysis, the formulation with added fiber and the commercial biscuits showed no significant difference regarding flavor and intent to purchase. Thus, the cookie developed herein has promising market potential, and it presents additional benefits due to its economic and nutritional appeal.

Modifications in water resistance and engineering properties of β-calcium sulphate hemihydrate plaster-superplasticizer blends

In this study, the effect of sulphonated naphthalene formaldehyde condensate (SNF) and polycarboxylate (PC) superplasticizers on the performance of β-calcium sulphate hemihydrate plaster has been discussed. A considerable improvement in the properties of β-hemihydrate plaster was observed with an increase in superplasticizer content. For 0.6 wt% SNF and PC content, a reduction of 18–20 % in water requirement is obtained and contributes 71–75 % enhancement in the compressive strength of modified pastes as compared to reference sample. The influence of superplasticizers on the hydration characteristics and morphology of the gypsum crystals have been studied using IR, SEM and Electrical Conductivity techniques. These studies indicate a significant influence of superplasticizers on the growth rates of the hydrates and leads to the formation of a dense and well compacted texture of crystals, thereby imparting high strength and better water resistance to the gypsum matrix than the reference material.

Evaluation of properties of gypsum plaster-superplasticizer blends of improved performance

The effect of SMF-based superplasticizer on the performance of β-hemihydrate plaster has been studied. A 0.6wt% SMF content contributes 69% enhancement in the compressive strength of modified paste as compared to reference sample. The influence of superplasticizer on the hydration characteristics and morphology of the gypsum crystals have been studied by XRD, TGA, SEM and Electrical Conductivity techniques. These studies showed that superplasticizer accelerates the rate of hydration and leads to the formation of a dense and well compacted texture of crystals, thereby imparting high strength and better water resistance to the gypsum matrix than the reference material.

Molten Salt Synthesis of SnS<sub>2</sub> Nanoparticles with Visible-Light Driven Photocatalytic Activity for the Degradation of Rhodamine B

SnS2 nanoparticles with perfectly crystalline morphology were synthesized via a molten salt synthesis route at a relatively low temperature. The resulting SnS2 nanoparcticles were characterized by X-ray diffraction (XRD), field scanning electron microscopy (FESEM), and UV-vis diffuse reflectance spectra (UV-vis). The observations of FESEM images showed that the sample consists of a large number of aggregates assembled with numerous nanoparticles packed into compact texture. The photocatalytic activity of the as-prepared SnS2 samples was evaluated by the degradation of RhB aqueous solution. The effect of the molar ratio of thiourea to SnCl2 on the photocatalytic activity was also investigated, and the result showed that the as-prepared SnS2 sample has high photocatalytic activity efficiency in the degradation of RhB aqueous solution when the molar ratio of thiouea to SnCl2 was 3.

Multiband compact texture unit descriptor for intra-band and inter-band texture analysis

The standard approach for extracting texture in multispectral images is to analyze intra-band spatial relationships in each spectral band independently and ignore inter-band spatial relationships. Analyzing both spatial relationships often yields better performance but suffers from being computationally cumbersome. In this paper, a solution for the simultaneous analysis of intra- and inter-band spatial relationships is proposed based on a new descriptor, named the multiband Compact Texture Unit (multiband C-TU). The proposed multiband C-TU descriptor was compared with the monoband C-TU and the Gray Level Cooccurrence Matrix (GLCM) methods in a supervised classification scheme, which used only texture information. Tests were conducted using panchromatic and pan-sharpened multispectral WorldView-2 images from three different sites. The average classification rates obtained by texture extracted from the panchromatic band using GLCM and monoband C-TU were 63.9% and 65.5% respectively. When pan-sharpened multispectral bands were used, these monoband texture methods recorded an average classification rate of 73.6% and 78.6%. When the three first Principal Component Analysis (PCA) bands were used, these monoband texture methods performed similarly to those for pan-sharpened multispectral bands. The proposed multiband C-TU descriptor extracted from the pan-sharpened multispectral bands recorded the highest average classification rate of 87.2%. When the proposed descriptor was extracted from the first three PCA bands, the average classification rate decreased by 8.3% compared to the use of the pan-sharpened bands. This suggested that inter-band spatial relationships were not preserved by the PCA transform.

Physico-mechanical characteristics and durability of calcium aluminate blended cement subject to different aggressive media

Three mixes were prepared from calcium aluminate cement (CAC) and 20 mass% water-cooled (WCS) slag or air-cooled slag (ACS). The pastes were prepared with the required water of standard consistency, cured under tap water until time of testing (1, 3, 7 and 28days). The durability of calcium aluminate blended cement was investigated by immersing the samples under tap water for 7days (zero time), and then immersed in 5% sodium chloride, 5% magnesium sulphate and 5% ammonium sulphate as aggressive media. Compressive strength, bulk density and apparent porosity were measured. X-ray diffraction analysis and scanning electron microscopy were studied to reveal their mineralogical and microstructural features. Compressive strength of neat CAC pastes are lower than those of CAC–WCS and CAC–ACS blends. Compressive strength of CAC pastes immersed in 5% NaCl, 5% MgSO4 or 5% (NH4)2SO4 increases with curing time up to 90days and then shows a slightly decrease up to 120days immersion time. The presence of Cl− or SO42− ions activates the hydration rate of CAC, CAC–WCS and CAC–ACS. The SEM micrographs of CAC–WCS and CAC–WCS indicate the presence of the thin flaky-plate like morphology of C2ASH8 and thin fibrous particles of C–S–H I,II, which reflects closed and compact texture.

Compact color–texture description for texture classification

Describing textures is a challenging problem in computer vision and pattern recognition. The classification problem involves assigning a category label to the texture class it belongs to. Several factors such as variations in scale, illumination and viewpoint make the problem of texture description extremely challenging. A variety of histogram based texture representations exists in literature. However, combining multiple texture descriptors and assessing their complementarity is still an open research problem. In this paper, we first show that combining multiple local texture descriptors significantly improves the recognition performance compared to using a single best method alone. This gain in performance is achieved at the cost of high-dimensional final image representation. To counter this problem, we propose to use an information-theoretic compression technique to obtain a compact texture description without any significant loss in accuracy. In addition, we perform a comprehensive evaluation of pure color descriptors, popular in object recognition, for the problem of texture classification. Experiments are performed on four challenging texture datasets namely, KTH-TIPS-2a, KTH-TIPS-2b, FMD and Texture-10. The experiments clearly demonstrate that our proposed compact multi-texture approach outperforms the single best texture method alone. In all cases, discriminative color names outperforms other color features for texture classification. Finally, we show that combining discriminative color names with compact texture representation outperforms state-of-the-art methods by 7.8%, 4.3% and 5.0% on KTH-TIPS-2a, KTH-TIPS-2b and Texture-10 datasets respectively.

A distinct and compact texture descriptor

In this paper, a statistical approach to static texture description is developed, which combines a local pattern coding strategy with a robust global descriptor to achieve highly discriminative power, invariance to photometric transformation and strong robustness against geometric changes. Built upon the local binary patterns that are encoded at multiple scales, a statistical descriptor, called pattern fractal spectrum, characterizes the self-similar behavior of the local pattern distributions by calculating fractal dimension on each type of pattern. Compared with other fractal-based approaches, the proposed descriptor is compact, highly distinctive and computationally efficient. We applied the descriptor to texture classification. Our method has demonstrated excellent performance in comparison with state-of-the-art approaches on four challenging benchmark datasets.

Role of polyaniline morphology in Pd particles dispersion. Hydrogenation of alkynes in the presence of Pd-polyaniline catalysts

AbstractTwo polyaniline (PANI) samples of various molecular masses were used for the preparation of palladium catalysts (with 2 mass % of Pd). The physicochemical features of starting polyanilines were found to substantially affect the size and extent of palladium nanoparticles aggregation. Strongly aggregated large palladium particles appeared in the PANI sample of more compact morphology (PANI-H), higher crystallinity and lower specific surface area. Pd nanoparticles of a definitively smaller size were formed in the more amorphous PANI sample of looser morphology (PANI-L) and the extent of particles aggregation was markedly lower. The catalytic properties of Pd/PANI samples were studied in a liquid phase hydrogenation of unsaturated triple bond (C≡C) in alkynes reactants, phenylacetylene, and cyclohexylacetylene. The 2 mass % Pd/PANI-L catalyst prepared using polymer of less compact texture exhibited much higher activity in both reactions. In the presence of the 2 mass % Pd/PANI-L catalyst, alkene products were formed with a high selectivity (approximately 90 %) attained at the almost complete conversion of alkynes. This highly selective hydrogenation of the C≡C to the C=C bond was related to the presence of an electroactive polymer, PANI, in close proximity with Pd active sites. Polyaniline could have a role in a steric effect as well as in a modification of adsorptive properties of Pd centres.

Influence of Grain Composition and Sintering Temperature on Performance of Silicon Carbide Refractory Material

Silicon carbide with diffierent granularity and three grain composition was used as raw material. Silicon carbide refractory material was prepared in oxidizing atmosphere at 1400 °C, 1450 °C and 1500 °C for 3 h. Performence of samples were researched by measurements of apparent porosity, bulk density, bending strength at room temperature, thermal shock resistance and thermal expansion rate, and analyzed by SEM. The results showed that samples sintered at 1400 °C have low thermal expansion rate and apparent porosity, high bending strength and bulk density, good thermal shock resistance, compact texture as well. It can be deduced that (1.0-0.5mm) / (0.5-0.1mm) / (45μm) / (5μm) = 50 / 17/ 20/ 13 is the best grain composition to improve integrated performance of silicon carbide refractory material.

Effect of Extrusion Temperature on the Microstructure, Textural and Functional Attributes of Carrot Pomace-Based Extrudates

Textural and functional attributes are the main decisive factor for acceptability and stability of the snack food in the market, whereas microstructural study is considered a powerful tool for understanding the behavior of these attributes. The extrudates prepared under the optimized conditions from rice flour, pulse powder and carrot pomace were evaluated for the thermal kinetics of color, hardness and microstructure; β-carotene; and vitamin C. The extrudates were sealed in metalized polypropylene, and the bags were then stored for 6 months in an incubator at temperature of 30C and 50% relative humidity. The increase in L-value, b-value and decrease in a-value, crispiness, β-carotene and vitamin C in carrot pomace-based rice extrudates was observed with the increase in extrusion temperature. The harder and compact texture in microstructural study of extrudates was observed with the increase in temperature. The decrease in L-value, b-value, crispiness, β-carotene and vitamin C, and increase in a-value and hardness extrudates was observed with the increase in storage period. Practical Applications Fruit and vegetable juices have become important in recent years because of overall increase in natural juice consumption as an alternative to the traditional caffeine-containing beverages such as coffee, tea or carbonated soft drinks. Carrot pomace is a by-product obtained during carrot juice processing. A promising way is to store the carrot pomace in dried form and utilize in the development of various food products specifically extrudates. The conversion of dried pomace by the application of novel and versatile technique of extrusion can be very useful both in terms of economic point of view and health benefits. The microstructural and textural changes in the product during storage are still not known. The effect of extrusion temperature and storage on the product microstructure, texture and functional attributes were evaluated for further applications of extrusion processing. Zero- and first-order models were also planned to study the thermal and degradation kinetics.

Influence of Additives on Performance of Silicon Carbide Refractory

Silicon carbide with diffierent granularity was used as raw material, quartz, silica fume, aluminum powder or alumina was used as additive with dosages of 1% (in mass, similarly hereinafter), 3% and 5%. Silicon carbide refractory material was prepared in oxidizing atmosphere at 1400 °C for 3 h. Performence of samples were researched by measurements of apparent porosity, bulk density, bending strength at room temperature, thermal shock resistance and thermal expansion rate, and analyzed by SEM. The results showed that samples added silica fume have low thermal expansion rate and apparent porosity, high bending strength and bulk density, good thermal shock resistance, compact texture as well. It can be deduced that 5% silica fume plays the excellent role to improve integrated performance of silicon carbide refractory material.

Preparation of Bi<sub>3.6</sub>Ho<sub>0.4</sub>Ti<sub>3</sub>O<sub>12</sub> Ceramics by Hot-Press Sintering

Hot-Press Sintering, a Method that Could Effectively Decrease the Densification Temperature due to the Applied Pressure, Was Employed to Prepare a New Kind of Ho3+ Doped Bi4Ti3O12 Ceramics, Bi3.6Ho0.4Ti3O12. The Effect of Preparation Parameters on the Crystal Phase, Density and Microstructure of the Ceramics Were Investigated. at First, Single-Phased Bi3.6Ho0.4Ti3O12 Powders Were Synthesized from Bi2o3, Tio2 and Ho2o3 Raw Powders by Solid-State Reaction and the Optimum Calcined Temperature Should Be 900 °C. The as-Synthesized Powders Were Further Densified at 750-900 °C to Prepare Bi3.6Ho0.4Ti3O12 Ceramics. Dense (relative Density Was 99.4 %) Bi3.6Ho0.4Ti3O12 Ceramics with a Compact Texture Were then Obtained by Hot-Press at 850 °C, about 150-200 °C Lower as Compared with Pressureless Sintering.

Head birefringence properties are associated with acrosome reaction, sperm motility and morphology

Birefringence in sperm heads reflects an organized and very compacted texture, indicating nuclear and acrosomal structural normality. This study performed a direct analysis of the acrosome integrity in single spermatozoa to verify whether a pattern of total or partial head birefringence reflected the acrosome status. The morphology in fresh samples was assessed according to World Health Organization criteria while the characteristics of birefringence were evaluated by polarized light. Acrosome integrity was evaluated by fluorescein isothiocyanate Pisum sativum agglutinin that binds selectively to the acrosome content. According to the results, a reacted acrosome was present in 96% of spermatozoa with partial birefringence and only in 35% of those with totally birefringent heads. A great proportion of sperm cells with normal morphology showed total birefringence both in the presence (59%) or in the absence of motility (45%; P<0.01), while in morphologically abnormal spermatozoa the frequency of total birefringence was comparable to that of partial birefringence irrespective of motility (26% and 27%, respectively, in motile spermatozoa; 22% and 19%, respectively, in immotile spermatozoa). These data support a strong association between partial birefringence and reacted acrosome and show that the patterns of birefringence vary depending on sperm motility and morphology.Human sperm cells are naturally birefringent when observed in a polarizing light due to the presence of longitudinally oriented protein filaments. The detection of birefringence in sperm heads reflects an organized and very compacted texture that indicates nuclear and acrosomal structural normality. Basically, three types of head birefringence have been observed: total, partial (localized in the post acrosomal region) and abnormal (absent or irregular). Data from electron microscopy has suggested a correlation between acrosome integrity and birefringence patterns. The aim of this study was to verify this hypothesis by direct analysis of the acrosome status in single spermatozoa. The morphology in fresh samples was assessed according to World Health Organization criteria while the characteristics of birefringence were evaluated by polarized light. Acrosome integrity was evaluated by fluorescein isothiocyanate Pisum sativum agglutinin that binds selectively to the acrosome content. According to the results, 96% of spermatozoa with partial birefringence had a reacted acrosome, while 65% of totally birefringent heads had an intact acrosome. A large proportion of sperm cells with normal morphology showed total birefringence both in the presence (59%) or in the absence of motility (45%; P<0.01), while in morphologically abnormal spermatozoa the frequency of total birefringence was comparable to that of partial birefringence irrespective of motility (26% and 27%, respectively, in motile spermatozoa; 22% and 19%, respectively, in immotile spermatozoa). These data support a strong association between partial birefringence and reacted acrosome and show that the patterns of birefringence vary depending on sperm motility and morphology.

EFFECT OF BARLEY FLOUR BLENDING ON FUNCTIONAL, BAKING AND ORGANOLEPTIC CHARACTERISTICS OF HIGH-FIBER RUSKS

Barley flour was incorporated into wheat flour at 0, 10, 20, 30 and 40% substitution levels for the preparation of high-fiber rusks. The gluten content and sedimentation value of the prepared rusk samples and the mixing time of the dough decreased while water absorption capacity increased with increase in the level of barley flour incorporation. Protein and glutelin contents decreased significantly on blending of barley flour to wheat flour. The rusks prepared from the blends also varied in their loaf weight, loaf volume and sensory characteristics. The rusk volume decreased with increasing amount of barley flour substitution. The color of rusks changed from creamish white to dull brown and a gradual hardening of texture was observed as the addition of barley flour increased. At the higher levels, the acceptability declined because of the compact texture of the crumb and the strong flavor of the product. The addition of 20% of barley flour to wheat flour produced acceptable rusks shown by sensory scores. PRACTICAL APPLICATIONS The present investigation relates to the use of barley flour incorporation in bakery product, such as rusks. Rusk is widely consumed in all countries; wheat flour is the main flour used, and the baking procedure includes mixing, fermentation, baking and roasting. At the present time, in India and also all around the world, there is an increased consumer demand for whole grain, and mixed grain baked products. Many consumers prefer products rich in fiber and have more health beneficial properties. However, modern consumer interest in nutrition and health may help restore barley's status as a significant component in the human diet. So, this investigation was undertaken to study the effect of barley flour supplementation on the functional, baking and organoleptic characteristics of high-fiber rusks.

Improved performance of GaAs-based micro-solar cell with novel polyimide/SiO2/TiAu/SiO2 structure

A novel interconnected structure consisting of a conventional polyimide layer (PM) and an additional SiO2/TiAu/SiO2 sandwich multilayer has been firstly proposed for improving the performance of GaAs micro-solar cell array. The specific experimental investigations on the array with 108 unit cells have demonstrated that the novel structure of PM/SiO2/TiAu/SiO2 can effectively enhance the open-circuit voltage from 75 to 84 V and the fill factor from 35% to 57%. The performance improvement of our devices can be attributed to two aspects. Firstly, the TiAu shielding film can prevent the incident light from penetrating into the GaAs substrate so as to induce the serious substrate leakage current. Secondly, the compact texture of SiO2 in the novel structure can reduce the perimere recombination due to the crackle or shrinkage of PM. It is indicated that the novel structure can distinctly reduce the leakage current and improve output characteristic of micro-solar cells.

Binding Performance of a Zirconia Framework Material and Veneering Porcelain

In this study, the binding performance of a Cercon-based zirconia framework material and special Cercon Ceram S zirconia veneering porcelain is discussed. Rectangular 30 mm × 20 mm × 2 mm porcelain blocks were made from zirconia using the CAD/CAM system. The 2 mm veneering porcelain was then sintered onto blocks at a temperature of 850-800°C with a loading speed of l mm/min. The shear bond strength of the interface was tested. Sintering was studied by visual observation, scanning electron microscopy, energy dispersive spectroscopy (EDS), thermal shock test and other methods. Excellent sintering results of the zirconia framework material and veneering porcelain can be achieved. The cross-sectional morphology of the samples, observed by SEM, shows a uniform, fine, and smooth texture for the veneering porcelain, whereas that of the zirconia framework material shows a rough surface with a uniform and compact texture. EDS results indicate that a small amount of A12O3 and SiO2 is present in the zirconia area, and no ZrO2 or Y2O3 is detected in the veneering porcelain area. No interlayer radial crack or flaw is found throughout the entire thermal shock test of the samples at 60-240°C. Thus, the cracking temperature of the samples is pegged at T&gt;240°C. The shear bond strength of the interface is 32.62±5.77 MPa. Chemical element infiltration exists between zirconia and the veneering porcelain, indicating the chemical bond between the two. An excellent match between the Cercon-based zirconia framework and the special veneering porcelain can be achieved, which can satisfy clinical requirements.

Profile-based roughness discrimination with pen-type texture sensor

Tactile discriminations of surface roughness using artificial sensors have been challenging. The modeling methods and parameters that have been using to describe the mechanical properties of rough surface are insufficient for haptic roughness. This paper proposes a method to characterize surface roughness based on the profiles of the surface. A compact handheld pen-type texture sensor with a right probe is developed for the measurement of surface profiles. Based on the contact force and the motion of the senor, profiles in the paths of scanning are estimated. The height variations of a profile are converted to a series of tactile stimuli to represent the contact stimulations in haptic explorations. The mean and the standard deviation of the amplitudes of stimuli are identified as haptic features that indicate the required tangential force to slide on the rough surface and how rough the surface is, respectively. Experiments show that the roughness on four kinds of sandpapers can be clearly distinguished by the proposed discrimination method.