image-dired-cmd-create-temp-image-options

image-dired-cmd-create-temp-image-options is a variable defined in `image-dired.el'.
Its value is

"%p -size %wx%h \"%f\" -resize \"%wx%h>\" -strip jpeg:\"%t\""

Documentation:
Format of command used to create temporary image for display window.
Available options are %p which is replaced by
`image-dired-cmd-create-temp-image-program', %w and %h which is replaced by
the calculated max size for width and height in the image display window,
%f which is replaced by the file name of the original image and %t which
is replaced by the file name of the temporary file.

You can customize this variable.