Brain anatomical variations among Malaysian population

Spatial normalization is an important task in neuroimaging analysis to compensate with the anatomical variations between different subjects. Current practice is to normalize the sample image to the reference brain atlas to ensure that the unbiased image-to-image comparison is possible. The available template nowadays is ICBM152, which derived from a Caucasian population. Since the brain anatomical variations has been reported especially for the inter-regional cohorts, the use of the ICBM152 template for other region subjects is questionable. In addition to that, several other factors such as age and gender have also been reported to have an effect to the brain morphometric. This study investigates the global brain shape measures for different group among Asian population. It is useful as a basis for further investigation on a more complex brain structure differences among local and inter-regional population. Later on, a group-specific atlas may be constructed to be used exclusively for Asian subjects. This study showed that gender factor has a significant effect on the brain shape while the age and race demonstrated no significant correlation

Illumination compensation for document images using local-global block analysis

This paper presents the illumination compensation technique for document images using local-global block analysis. Imbalance illumination will affect the performance of classification and segmentation process because the darker regions conceal the information of the image. This method will split the image into non-overlapped blocks, and utilize the information within the local and global area of the image. The output images were binarized with simple global thresholding technique and the result shows that the output image is comparable in quality with the existed method. A comparative result will be presented with other document binarization methods

Voxel-based morphometric difference in metabolic activity of 50 to 73 years old healthy adult brain: A PET/CT study

Healthy adult exhibits variants of 18F-FDG distribution of cerebral glucose metabolism associated with age. This study was conducted to investigate the hypometabolism and hypermetabolism as a function of gender in healthy adults unrelated to dementia. The subjects consisted of 21 males aged 51 to 66 (mean + SD = 57.81 + 4.792) and 15 females aged 50 to 73 (mean + SD = 62.8 + 5.906). Six data of equal gender were randomly chosen from the subjects to investigate the difference in metabolic activity. The result showed that hypometabolismwas detected at cerebrum, cerebellum, parahippocampalgyrus, superior frontal gyrus, superior temporal gyrus, frontal lobe and posterior lobe that were not exclusively showing dementia-related diseases but only a sign of mild cognitive decline with increased age. In healthy elderly, hypometabolismwas also seen in the anterior regions of the brain that related to executive function and performance of attention. Preserved glucose consumptionwas seen as both hypo- and hypermetabolized in the cerebrum and cerebellum region. This finding was supported by previous studies that a normal daily function of an AD patient was preserved even with evidence of cognitive decline. Nevertheless, there were gender effect differences in metabolic activity between male and female healthy adults. Hypometabolism was significant in right cerebrum, right cerebellum and left cerebellum for male but hypermetabolic in female at left cerebrum region. On the other hand, only female subject showed a hypometabolic area in thalamus and parahippocampalgyrus due to effect of estrogen where older female aged 50 and above were in menopausal condition unless HRT were taken

Variable illumination compensation for pigskin leather images using local and global block analysis

Variable illumination seems to be a main challenge to any automatic image processing system particularly in the segmentation and recognition part. The new intensity variations, which do not presence in the original image, may lead to a false segmentation result. In this research, we present a method to compensate the imbalance illumination in pigskin leather texture image. The main objective of this research is to offer an alternative pre-processing tool for further image enhancement procedures that is fast, simple and robust. The method utilizes the information within the local and global area of the image. The results are promising as the output image illumination condition is improved. In addition to that,the performances are either similar or better if to be compared to other established methods. However, the output images are affected by the visibility of the block boundaries. It happens due to the rapid intensity variation across the block boundaries, which is caused by the inaccurate residual selected for the normalization step. The next objective of this thesis is to remove the blockiness effect while still maintain the image attributes and improve the illumination condition. Some sets of modifications are employed to the basic model of local-global block analysis (B-LGBA) in order to eliminate the blockiness effect including horizontal improvement (HI-LGBA), vertical improvement (VI-LGBA), horizontal-vertical improvement (HVI-LGBA) and vertical-horizontal improvement (VHI-LGBA). The results produced by the enhanced LGBA illustrated that the modifications to be made are depending on the illumination trend. If the illumination is in one direction, the single modification is sufficient to remove all the boundaries. However, if the illumination is multi-directional, combined modifications are necessary, with the less-influencing direction must be dealt first. The accuracy of the proposed method is evaluated via the error of the numbers of the segmented region counted in the output image. Most of the outputs are oversegmented due to the existence of other low-intensity pixels which are contributed by the non-uniform surface of the sample and also the blocky pattern.From our 20 samples consist of different illumination types, the HVI -LGBA and VHI-LGBA yielded the lowest percentage of the errors with 29.52% and 35.43% compared to the errors produced by the B-LGBA which is equal to 120.35%

Illumination compensation in pig skin texture using local-global block analysis

Variable illumination in a texture is a common problem occurs to a real-time image modalities. The imbalance illumination in a texture creates virtual regions within one image, hence it affects the performance of the classification methods because it introduced an artifact patterns or virtual regions to an image. This paper presents a method to overcome the variable illumination problem in a pig skin texture using the information in the local and global blocks. The focus of this paper is to provide a fast, reliable and safe method to stabilize the lighting in an image. Pig skin texture is selected because it has a special pattern characteristic that needs to be preserved. The results show that in terms of the fluctuations contrast amplitudes in an image, the local-global method give better results than the standard homomorphic filtering technique