## 1 Introduction  
Age-related macular degeneration (AMD) is the leading cause of vision impairment and severe visual loss amongst older individuals in developed countries [1]. A global meta-analysis has shown that it was estimated that the number of people with age-related macular degeneration was approximately 196 million in 2020, increasing to 288 million in 2040 [2]. Therefore, it is indeed a significant public health problem. Choroidal neovascularization (CNV) is the hallmark of exudative AMD. Progression of CNV can result in fluid exudation, subretinal hemorrhage, subretinal fibrosis, photoreceptor damage, and eventually vision loss [3]. Early detection of CNV in patients with exudative AMD is critical for early treatment and the prevention of vision loss [4]. Both fluorescein angiography (FA) and indocyanine green angiography (ICGA) are chief diagnostic methods for CNV detection [5]. However, both modalities are considered invasive and time consuming, requiring intravenous dye injections, while also posing a potential risk for anaphylaxis [6]. Optical coherence tomography (OCT) is a non-invasive modality for acquiring cross-sectional volumetric images of the tissues. In the recent past, it has been widely used as a diagnostic tool in the field of dermatology and ophthalmology. For example, the findings of OCT can help clinicians diagnose and determine the extent of skin and choroidal tumor [7; 8], For detecting the presence of CNV, OCT enables visualization of the morphological features of the fibrovascular complex and the exudative fluid accumulation. However, it cannot distinguish vasculature from fibrous and other surrounding tissues clearly. Therefore, the precise location and activity of the CNV cannot be determined [9]. Optical coherence tomographic angiography (OCTA) is a novel imaging tool, which allows visualization of the retinal and choroidal microvasculature in vivo by detecting intravascular blood flow [10]. In general, OCTA monitors blood flow through detecting changes in reflectivity, which are thought to be related to the dynamic motion of red blood cells, and are facilitated by sequential cross-sectional scans, which are then repeated at the same location over time. This process is repeated throughout many cross-sectional locations in the area of interest to create a volumetric (three-dimensional) vascular map [11]. Because it is based upon flow motion detection, there is no need for contrast dye injections. Additionally, the OCTA image could be obtained in only 30-60 s, which is quicker when compared to FA and ICGA, both of which require approximately 10-30 min. Furthermore, layer-by-layer and three-dimensional volumetric analyses of the choriretinal vascular architecture are possible using OCTA imaging, which could not be performed through the use of conventional imaging modalities such as FA and ICGA. Precise localization of CNV is important for the purpose of both evaluating therapeutic effects and predicting prognoses. OCTA is a safe, fast, and noninvasive method for the diagnosis and analysis of microvascular abnormalities associated with retinal vascular disease and AMD. However, CNV lesions are found in a variety of shapes, sizes, and locations, with the flow visualization within these structures possibly being significantly different. Moreover, OCTA images are degraded by projection and corrupted by speckle noise, resulting in a low contrast between CNV and its background [12]. Therefore, interpretation of the images acquired through the use of this technology remains challenging. We intend to propose a judgment architecture in order to assist ophthalmologists in implementing CNV more efficiently. Since OCTA images often have a large amount of noise, we must try to remove the noise in order to find the main blood vessel region. To do this we first converted the color space to the CIELAB color space, retain the L-channel, and remove the A-channel and B-channel to reduce unnecessary information in the image, while retaining as much important information as possible in the original image.