[Solved] Sequence processing consumes all RAM

[jmac698]

I was trying to magick identify *.tif on hundreds of images, and found that magick buffers all the images into ram first and it's very slow. Certainly this simple operation could be much faster. I recall something about setting the buffer size for magick, that might help as well. But I would call this a serious limitation. I was able to write a quick Python program to get the stats of every image and it matches the magick output, and was much faster.

Should I consider this a bug report? Or a feature request? Or is there something I can set?

I had the same problem with finding the mean of all images. Of course when it comes to median, magick can be excused because the simple way would need all images at once.

[snibgo]

Try "-ping" to prevent the images being stored when finding the dimensions.

The general solution is to execute one command per image, and put that command within a shell loop. For both bash and Windows BAT, the shell loop command is "for", but the syntax is different.

[jmac698]

ok, thanks for the tip, here is sample code to process in a loop, using the scripting in cmd.exe (windows)

Code: Select all

@ECHO OFF
rem for loops in a batch file, over filenames

rem this is required to do for loops (setting variables within the loop)
SETLOCAL ENABLEDELAYEDEXPANSION

rem for loop, for %%f in (set).

rem parameter checking

if "%1%"=="" (
  call :display_usage
  exit /b
)

if "%1%"=="/h" (
  call :display_usage
  exit /b
)

if /i "%1%"=="/?" (
  call :display_usage
  exit /b
)

FOR %%f IN (%1) DO (
  magick identify %%f>%%f.txt
  echo %%f
  rem show how to change a variable
  set /a y=y+1
  rem if you output %y% it will never change
  rem to use a changed var, need to have SETLOCAL ENABLEDELAYEDEXPANSION

)
echo !y! files processed.

rem end program here, erase used variables (useful in case we are called externally)
ENDLOCAL
exit /b

:display_usage
echo.
echo identify multiple files with imagemagick v7
echo Usage: identall filespec
echo   where filespec specifies files such as *.tiff
echo   example: identall *.jpg
exit /b