Variable: image-dired-thumb-naming

image-dired-thumb-naming is a customizable variable defined in image-dired.el.gz.

Value

sha1-filename

Documentation

How image-dired names thumbnail files.

When set to sha1-filename the name of thumbnail is built by computing the SHA-1 of the full file name of the image.

When set to sha1-contents the name of thumbnail is built by computing the SHA-1 of first 4KiB of the image contents (See image-dired-contents-sha1).

In both case, a "jpg" extension is appended to save as JPEG.

The value of this option is ignored if Image-Dired is customized to use the Thumbnail Managing Standard or the per-directory thumbnails setting. See image-dired-thumbnail-storage.

This variable was added, or its default value changed, in Emacs 30.1.

View in manual

Probably introduced at or before Emacs version 30.1.

Source Code

;; Defined in /usr/src/emacs/lisp/image/image-dired.el.gz
(defcustom image-dired-thumb-naming 'sha1-filename
  "How `image-dired' names thumbnail files.
When set to `sha1-filename' the name of thumbnail is built by
computing the SHA-1 of the full file name of the image.

When set to `sha1-contents' the name of thumbnail is built by
computing the SHA-1 of first 4KiB of the image contents (See
`image-dired-contents-sha1').

In both case, a \"jpg\" extension is appended to save as JPEG.

The value of this option is ignored if Image-Dired is customized
to use the Thumbnail Managing Standard or the per-directory
thumbnails setting.  See `image-dired-thumbnail-storage'."
  :type '(choice :tag "How to name thumbnail files"
                 (const :tag "SHA-1 of the image file name" sha1-filename)
                 (const :tag "SHA-1 of the image contents" sha1-contents))
  :version "30.1")