@echo off

set fmt=jpg

set fmt_all=*.jpg *.png *.bmp



rem --- ファイルリスト作成 ---

type nul > list.txt

if "%cd:~-1%" == "\" (

  set current_dir=%cd%

) else (

  set current_dir=%cd%\

)

for /f "delims=" %%C in ('dir /b /Oen %fmt_all%') do (

  echo "%current_dir%%%~C">> list.txt

)



rem --- 連番 1.tmp_jpg, 2.tmp_jpg, 3.tmp_jpg, ... にリネーム ---

type nul > newlist.txt

for /f "tokens=1* delims=:" %%C in ('type list.txt ^| findstr /n /C:"."') do (

  if %%C gtr 1000000 goto :eof

  ren %%D %%C.tmp_%fmt%

  echo %%C.tmp_%fmt%>> newlist.txt

)



rem --- 連番 000000.jpg, 000001.jpg, 000002.jpg, ... にリネーム ---

setlocal enabledelayedexpansion

set number2=0

for /f %%C in ('type newlist.txt') do (

  set new=00000!number2!

  ren "%%C" !new:~-6!.%fmt%

  set /a number2 += 1

  if !number2!==1000000 goto :eof

)

endlocal