  Solar corona, the last main layer of the atmosphere of the Sun, is detectable
in the EUV and X-ray. The corona is expanding into space up to millions of
kilometers and is observable during the eclipse. The temperature is increasing
about millions of Kelvin. The investigation of this layer is significant for
solar physicists because it is dynamic and features. Active regions (AR) and
solar mass ejections (CMEs) are the important features in the solar corona. In
this research, the solar limb and coronal width is studied from full-disk
images at $284 \AA$ taken by SOHO/EIT during eleven-year period (2000-2010).
Next, using image processing methods and by applying region growing function,
the corona is segmented and extracted from images in different angles. The
radial velocities of CMEs are extracted.
