Image binarization method for markers tracking in extreme light conditions

Image binarization is one of the fundamental methods in image processing and it is mainly used as a preprocessing for other methods in image processing. We present an image binarization method with the primary purpose to find markers such as those used in mobile 3D scanning systems. Handling a mobile 3D scanning system often includes bad conditions such as light reflection and non-uniform illumination. As the basic part of the scanning process, the proposed binarization method successfully overcomes the above problems and does it successfully. Due to the trend of increasing image size and real-time image processing we were able to achieve the required small algorithmic complexity. The paper outlines a comparison with several other methods with a focus on objects with markers including the calibration system plane of the 3D scanning system. Although it is obvious that no binarization algorithm is best for all types of images, we also give the results of the proposed method applied to historical documents.

Design of Massive Image Duplicate Search Algorithm in Cloud Computing Environment

Massive image replay algorithm adopts cloud computing technology to realize image uploading, processing and classification on cloud platform. Image classification is realized by image classifier. Zernike matrix was used to compare the classified images and determine the pseudo-edge blocks around the image. According to the pixel value of the image, the binarization method was used to process the image. After processing, edge detection and line detection were carried out to determine the real image size. The similarity of two real images is calculated by normalized similarity criterion, and the image repetition is judged accordingly. The results show that the accuracy of the algorithm is higher than 99%, and the accuracy of the algorithm is higher than that of the comparison algorithm, and the accuracy of the algorithm is the highest when the similarity threshold is 0.8∽0.9.

Segmentation Analysis in Powdery Mildew Infested (Sphaerotheca Fuliginea) Cucumber Leaves

In this document, we propose the recognition of powdery mildew in cucumber leaves based on image processing. Two cucumber cycles were established and infested with powdery mildew. As the disease developed, photos were taken to perform the analysis. Two hundred photographs were manually preprocessed eliminating the background and leaving only leaves infested with the disease. The images were segmented using three threshold binarization techniques: gray scale binarization, RGB binarization and K-means algorithm with initially located centroids. The results were compared between the different methods. The gray scale binarization as well as the RGB binarization allowed locating the disease based on a percentage of the lighter shades, although the latter method analyzes each one of the different color layers. The K-means algorithm identified groups with similar characteristics around provided centers. A false positive detection test was also performed with 25 previously processed photographs. The experimental results show that the proposed gray scale binarization method better results for the recognition of the disease than the other methods.

Choroidal structural changes determined by the binarization method after intravitreal aflibercept treatment in neovascular age-related macular degeneration

AIM: To assess the choroidal structural alterations after intravitreal injection of aflibercept in neovascular age-related macular degeneration (nAMD). METHODS: Fifty eyes with treatment-naïve nAMD were evaluated at baseline, 3rd, and 12th month. Fifty eyes of 50 healthy subjects were also included as controls. Choroidal thickness (CT) was measured in the subfoveal region. Total circumscribed choroidal area (CA), luminal area (LA), stromal area (SA), and choroidal vascularity index (CVI) was calculated using Image J. RESULTS: At baseline, subfoveal CT was increased in nAMD patients compared to controls (P=0.321). Eyes with nAMD had a significantly increased total circumscribed CA and SA (P=0.041, 0.005, respectively). The CVI was decreased (P=0.038). In the 3rd month, the subfoveal CT, LA, and CVI revealed a decrease (P=0.005, P=0.039, 0.043, respectively). In the 12th month, subfoveal CT, LA, and CVI were decreased in comparison to baseline measures (P<0.001, 0.006, 0.010, respectively). CONCLUSION: Significant structural alterations are found after intravitreal aflibercept treatment during the 12-month follow-up, in particular at the third month, in eyes with nAMD.

Involvements of choroidal vascular structures with local treatments in patients with diabetic macular edema

Purpose: To examine changes of the choroidal morphology in patients with diabetic macular edema (DME) before and after local treatments. Methods: This study was on 20 eyes with DME, observed for more than 24 months. All patients underwent laser photocoagulation (Laser), sub-tenon triamcinolone acetonide injection (TA), or intravitreal aflibercept injection (IVA). Central macular and choroidal thicknesses (CMT/CCT), and choroidal vascular structures consisting of the total choroidal area (TCA), luminal area (LA), and stromal area (SA) were measured by a binarization method. The ratios of LA in TCA were eventually determined as the L/C ratio in each case. Results: The L/C ratio significantly decreased for 24 months in patients with DME ( p = 0.01), whereas no significant differences were noted in other parameters including TCA, LA, SA, or CCT. Among patients treated with Laser ± TA ± IVA, a significant correlation was found between a high L/C ratio at pretreatment and a lower cumulative number of injections (1–2 times/24 months) ( p = 0.04). The L/C ratio in pretreatment showed a significantly inverse correlation with CMT (−0.60, p = 0.02) and subsequent BCVA (logMAR) (−0.59, p = 0.03). Conclusion: This study highlighted that the L/C ratio in pretreatment might predict a change of the visual acuity in DME.