47 research outputs found
Image Cropping under Design Constraints
Image cropping is essential in image editing for obtaining a compositionally
enhanced image. In display media, image cropping is a prospective technique for
automatically creating media content. However, image cropping for media
contents is often required to satisfy various constraints, such as an aspect
ratio and blank regions for placing texts or objects. We call this problem
image cropping under design constraints. To achieve image cropping under design
constraints, we propose a score function-based approach, which computes scores
for cropped results whether aesthetically plausible and satisfies design
constraints. We explore two derived approaches, a proposal-based approach, and
a heatmap-based approach, and we construct a dataset for evaluating the
performance of the proposed approaches on image cropping under design
constraints. In experiments, we demonstrate that the proposed approaches
outperform a baseline, and we observe that the proposal-based approach is
better than the heatmap-based approach under the same computation cost, but the
heatmap-based approach leads to better scores by increasing computation cost.
The experimental results indicate that balancing aesthetically plausible
regions and satisfying design constraints is not a trivial problem and requires
sensitive balance, and both proposed approaches are reasonable alternatives.Comment: ACMMM Asia accepte
Towards Diverse and Consistent Typography Generation
In this work, we consider the typography generation task that aims at
producing diverse typographic styling for the given graphic document. We
formulate typography generation as a fine-grained attribute generation for
multiple text elements and build an autoregressive model to generate diverse
typography that matches the input design context. We further propose a simple
yet effective sampling approach that respects the consistency and distinction
principle of typography so that generated examples share consistent typographic
styling across text elements. Our empirical study shows that our model
successfully generates diverse typographic designs while preserving a
consistent typographic structure
Enhancement of the Catalytic Activity Associated with Carbon Deposition Formed on NiO/Al2O3 during the Dehydrogenation of Ethane and Propane
In the recent study, the dehydrogenation of isobutane to isobutene was accomplished using a NiO/γ-Al2O3 catalyst, and significant improvement in the time-on-stream yield of isobutene was accomplished. During the normal catalytic dehydrogenation of alkanes, the catalyst is covered by the carbon deposition that is generated during the reaction, which drastically reduces activity with time-on-stream. Therefore, no examples of the catalytic dehydrogenation of isobutane have yet been reported. This study used either ethane or propane as a source of isobutane to examine whether the activity was improved with time-on-stream. As a result, in the dehydrogenations of both ethane and propane on a NiO/γ-Al2O3 catalyst, the catalytic activity decreased with time-on-stream when the supporting amounts of NiO was small. By contrast, when the supporting amount of NiO was large, the catalytic activity improved with time-on-stream. The results using a NiO/γ-Al2O3 catalyst with small and large NiO loadings were similar to those of isobutane dehydrogenation and it was confirmed that the dehydrogenation activity was improved with time-on-stream in the catalytic dehydrogenations of ethane, propane, and isobutane using large NiO loadings. Intermediate behavior using a moderate amount of NiO loading, which was not detected in the dehydrogenation of isobutane, was also observed, which resulted in a maximum yield of either ethylene or propylene at 2.0 or 3.25 h on-stream, respectively. We concluded that the reason the catalytic activity did not improve with time-on-stream when using a NiO/γ-Al2O3 catalyst was because the supporting amount of NiO was too small. These results show that activity with time-on-stream could also be improved in the dehydrogenations of other alkanes
Carbon Deposition Assisting the Enhancement of Catalytic Activity with Time-on-Stream in the Dehydrogenation of Isobutane on NiO/Al2O3
In the transformation reaction of alkanes to alkenes via catalytic dehydrogenation, it is generally accepted that the so-called catalytic deactivation behavior will occur. This phenomenon causes a drastic reduction in activity with time-on-stream. It is understood that carbon deposition generated during the reaction then covers the surface of the catalyst, and this leads to a drastic decrease in activity. However, contrary to this common wisdom, our laboratory reported that the dehydrogenation of isobutane to isobutene on NiO/γ-Al2O3 within a specific range of NiO loading in the presence of CO2 actually improved the yield of isobutene with time-on-stream. Since few such cases have been reported, in this study, isobutane was dehydrogenated in the presence of CO2 using NiO/α-Al2O3 as the catalyst with 20% NiO loading and improvement was again observed. In order to investigate the cause of the improvement, both NiO/γ-Al2O3 and NiO/α-Al2O3 with 20% NiO loading were examined in detail following the reaction. According to TEM analysis, both catalysts were covered with a large amount of carbon deposition after the reaction, but there was a difference in the types. The carbon deposition on NiO/γ-Al2O3 had a fibrous nature while that on NiO/α-Al2O3 appeared to be a type of nanowire. Raman spectroscopy revealed that the carbonaceous crystal growth properties of two forms differed depending on the support. In particular, a catalytically active species of metallic nickel was formed in a high degree of dispersion in and on the above two forms of carbon deposition during the reaction, and this resulted in high activity even if the catalyst was covered with a carbon deposition
Enhancement of Catalytic Activity Associated with Carbon Deposits Formed on NiO/γ-Al2O3 Catalysts during Direct Dehydrogenation of Isobutane
The dehydrogenation of isobutane in the presence of CO2 over NiO supported on γ-Al2O3 was examined. For comparison, Cr2O3 supported on γ-Al2O3 was also used. It is generally accepted that a catalyst used for the dehydrogenation of various alkanes will suffer catalyst deactivation due to the formation of carbon deposits. In the present study, the yield of isobutene was significantly decreased with time-on-stream due to carbon deposition when using Cr2O3(x)/γ-Al2O3, in which x indicates the loading of a corresponding oxide by weight %. However, carbon deposits also were evident on NiO(x)/γ-Al2O3, but the yield of isobutene was enhanced with time-on-stream depending on the loading (x). This indicates that the contribution of the carbon deposition in the dehydrogenation on NiO(x)/γ-Al2O3 definitely differed from that on an ordinary catalyst system such as Cr2O3(x)/γ-Al2O3. In order to confirm the advantageous effect that carbon deposition exerted on the yield of isobutene, NiO(x)/γ-Al2O3 was first treated with isobutane and then the catalytic activity was examined. As expected, it became clear that the carbon deposits formed during the pretreatment contributed to the enhancement of the yield of isobutene. The presence of a Ni-carbide species together with the metallic Ni that was converted from NiO during dehydrogenation definitely enhanced of the yield of isobutene. Although carbon deposition is generally recognized as the main cause of catalyst deactivation, the results of the present study reveal that carbon deposition is not necessarily the cause of this phenomenon