A method for evaluating a color picture tube includes displaying on a
display surface of a color picture tube a measurement pattern including a
plurality of first patterns arranged at different positions relative to
fluophor dots of said color picture tube and a plurality of second
patterns near said first patterns and sufficiently large relative to said
fluophor dots. A first image is obtained using an imaging element to
image said displayed measurement pattern. A second image is obtained
using said imaging element to image while controlling light intake to
allow brightness components of no more than about 1% of maximum luminance
from said first image to be separated from noise and imaged. A third
image is created by combining said first image and said second image
while adjusting scales according to a light intake ratio. From said third
image, display center positions of said plurality of first patterns is
calculated using said second pattern positions. Discrete fluophor
emission intensity distributions is calculated for each of said plurality
of first patterns. An electron beam intensity distribution is obtained by
matching display center positions of said plurality of first patterns and
combining said plurality of first patterns.