Our sample (see Table 1) consists of 104 dwarf galaxies observed with the Wide Field and Planetary Camera 2 (WFPC2) using the WF3-fix aperture (proposals GO 8192 and 8601) and with the Advanced Camera for Surveys (ACS) (proposals 9771 and 10235). All HST observations were carried out with the filters F606W and F814W, the response characteristics of which can be transformed to the filters V and I in the Johnson-Cousins system. The exposure times were 600s in each filter for the WFPC2 sample. The ACS images were taken with the exposure times of 900 and 1200s in the F606W and F814W filters, respectively.