File Size Accumulation Bug

Please add information about OS/platform and Inkscape version (see Inkscape menu 'Help > About Inkscape').

To allow further investigation, please attach a sample SVG file, and provide more details about the steps "(…) delete an elements and and import a new one (…)": what file formats are you importing, and how? Could you attach such a drawing which you import into an existing Inkscape SVG document, too?

Sorry, should have thought about that: Windows 7 with the latest stable version of Inkscape 0.48.5 r10040.

Sample file attached. These element have been picked from an .ai file after opening it in Inkscape. The "Arrows" file is what remained after deleting most of the elements in the "How to images" file.

For example, when I delete all elements except the arrows, the file size remains at 3.31MB

For example, when I delete all elements except the square background, the file size remains at 3.29MB

When creating a new file with the same square background (same size and color, the virgin file is only 1.70KB.

However, the problem seems to be significantly worse when dealing larger .png elements. (Have not used other file types.)

I am using the import function provided in Inkscape's menu (File > Import) and the element is embedded (not linked).

(Note: It's unclear what 'The "Arrows" file' mentioned in the earlier comment relates to (it was not provided) - below answer is based on the actual contents of the file "How to images.svg" without access to the original AI file from which the clip art was imported into the Inkscape document.)

Quick answer:
Use 'File > Vacuum Defs' from time to time to remove unreferenced resources (clip-paths, masks, etc.) from the current document.

Background:
The objects imported from the AI file are actually masked bitmap images inside nested clipped groups. The masks themselves are bitmap images too (which are used for the alpha channel of the bitmap images).

If such a clipped (or masked) group is ungrouped or deleted, or a masked (or clipped) bitmap image itself is deleted, the clip-paths and masks are retained in the <defs> section. Clip-paths and masks are only removed from the <defs> section if the clip or mask is released via corresponding menu command (see menu 'Object'). The command 'File > Vacuum Defs' can be used to cleanup such remains in the current document.

The file size of the attached example shrinks from 3.6 MB to 306 KB after having vacuumed the defs and saved again.

Proposing to link as duplicate to
- Bug #443229 “Embedded alpha channels (masks) aren't removed from file when the images are deleted”
  <https://bugs.launchpad.net/inkscape/+bug/443229>

Thank you! That definitely solved the problem. A file I was about discard and had started to redo, was reduced from almost 30MB to 1.8 MB. In other words, not a bug, but user ignorance.

Is there a reason for retaining clip-paths and masks instead of deleting them automatically by clicking "Delete"?

On 2014-10-02 22:17 , Vidar Bentzen wrote:
> Is there a reason for retaining clip-paths and masks instead of
> deleting them automatically by clicking "Delete"?

Haven't seen a comment by a core developer about this yet (same question in comment #9 of bug #443229).

Linking as duplicate to earlier bug #443229 - if you disagree and think this was done in error, please add a comment here (bug #1376836) and revert the duplicate status.