1. A wide dynamic range image capturing apparatus comprising: an image capturing device for capturing image data having an electric charge accumulation period varying every a frame; a preprocess block for performing DC adjustment, gain adjustment, and gamma characteristics adjustment with respect to the image data; a data storage memory for storing the image data; a memory control block for controlling a write or read operation of the image data with respect to the data storage memory; an image combining block for performing a combining operation process with respect to two frames of image data having the different electric charge accumulation periods to generate combined image data; and an image processing block for performing video signal processing with respect to the combined image data, wherein the memory control block can perform in parallel a process of writing a current frame of image data captured by the image capturing device into the data storage memory, a process of reading a previous frame of image data stored in the data storage memory, and a process of writing the combined image data generated in the image combining block into the data storage memory.