# Staining-Independent Malaria Parasite Detection and Life Stage Classification in Blood Smear Images
## 1 Introduction  
Red blood cells (RBCs) play an important role in oxygen transmission of organs; thus, they must traverse narrow blood vessels without undergoing destruction. During the intra-erythrocytic stage of malaria parasite infection, red blood cells undergo remarkable changes [1]. Such parasitic invasion supports survival of the parasite within the host red blood cell and often leads to an increased incidence rate of the disease that includes cerebral malaria and anaemia [2]. Malaria cannot be treated until it is diagnosed. Typical symptoms of malaria infection include fever, muscle fatigue, and headaches [3]. If a delayed diagnosis or treatment occurs, it will lead to anaemia and block the capillaries that carry blood to the brain [4]. Malaria is a disease transmitted by the female Anopheles mosquito and ranks among the foremost global public health concerns. This severe parasitic infection stands as a primary contributor to illness and death in tropical and sub-tropical regions worldwide. According to the World Health Organization (WHO), in the past 2 decades, the number of malaria infections has seen a remarkable decline, plummeting by 76% from 22.8 million cases in 2000 to 5.4 million cases in 2021. Additionally, the incidence rate has substantially dropped by 82%, falling from 17.9 to 3.2 cases per 1000 population at risk in the Southeast Asia region [5]. Five different species of plasmodium parasite can infect humans, including _P. falciparum_, _P. vivax_, _P. ovale_, _P. malariae_, and _P. knowlesi_. Each of these undergoesfour distinct stages in their life cycle, comprising four distinct phases in their development: ring, trophozoite, schizont, and gametocyte [6]. Among them, only four are considered real parasites that can infect humans, while _P. knowlesi_ is still considered a zoonotic malaria. _P. vivax_ stands as the prevailing parasite in the WHO Region of the Americas, contributing to 64% of malaria cases. Its prevalence exceeds 30% in the WHO Southeast Asia region and reaches 40% in the Eastern Mediterranean regions [7]. Malaria is a treatable illness, with available medications for its management, including preventive drugs for travelers who visit malaria-endemic areas. However, despite active research and field studies, there is currently no effective malaria vaccine. Once infected by malaria, it advances swiftly, underscoring the critical significance of timely diagnosis [8]. Due to the varying morphologies exhibited by different species of plasmodium parasites throughout their distinct life stages, to classify a certain class of a malaria-infected red blood cell in laboratory diagnosis, an experienced technician is required. Currently, the most common method for malaria diagnosis involves the use of light microscopy [9]. While the microscopic examination method is conventional, it does come with the drawback of being time consuming and requiring the expertise of a well-trained technician. It is common to have well-trained microscopists who can diagnose malaria accurately and effectively in well-funded medical facilities in large cities where malaria is rarely encountered. While on the other hand, the situation takes a different turn in developing countries, especially in some remote villages where malaria is more prevalent. The diagnostic method in these regions is often inaccurate and inefficient. The potential problems of this diagnosis arise from (a) the high cost of training microscopists and (b) inaccurate diagnosis results due to duplication work, limited experience, or mental and physical exhaustion [10]. Moreover, malaria cannot be treated until it is diagnosed. The delayed diagnosis or treatment will lead to anaemia and block the capillaries that carry blood to the brain. As a result, the infected and destroyed red blood cells will kill malaria-infected patients [3; 4; 11]. Thus, fast diagnosis and acute treatment of this illness are very helpful to reduce mortality.