Understanding of -buildexifthumb option

[foxy]

Hello,

I have a question regarding -buildexifthumb.

I have some pictures for which the smartphone does not create an embed thumbnail. My target is to create the thumbnails so it is easier and faster to deal with the files.

Unfortunately, I dont get it to work with the option -buildexifthumb. No thumbnail is created.

I can reproduce it with files where the camera creates a thumbnail already. I can reproduce it by removing the thumbnail before (with option -rexifthumb) - then also no thumbnail is created.

Is this intended? What is the purpose of -buildexifthumb? Only to re-create the thumbnail if one is available alreaday?

Best Regards,
foxy

[xnview]

could you send me a sample file?

[foxy]

See the files attached. Only the file IMG_3355 has the an embed thumbnail in it (see screenshot; thumbnail created by camera). For the other two files it is not possible to add a thumbnail with for example

Code: Select all

.\nconvert.exe -buildexifthumb -overwrite -v .\IMG_20220823_135943_1_small.jpg

There is no change.

Output of verbose is

Code: Select all

** NCONVERT v7.112 (c) 1991-2021 Pierre-E Gougelet (May 31 2022/14:43:37) **
        Version for Windows Xp/Vista/7 x64  (All rights reserved)
** This is freeware software (for non-commercial use)

A JPEG TrueColor (v1.1) (RGB) - JPEG was recognized : .\IMG_20220823_135943_1_small.jpg
    Width:1000 Height:750 with 16777216 colors
    Nplanes : 1      Bitscount : 24
    Bytes Per Plane : 3000
    xdpi : 72         ydpi : 72
Conversion of .\IMG_20220823_135943_1_small.jpg into .\IMG_20220823_135943_1_small.jpg OK

##########################Files opened: 1
Files written: 1

[xnview]

right, it's the same problem in XnView

[foxy]

So it's a bug and will be resolved (somewhen)?