Jpegtrans with

[Nick]

Hi,

I use: nconvert -v -keepfiledate -jpegtrans exif *.jpg
to convert my holiday pictures without (!!) loss.

My question is: The only purpose is to rotate losslessly according to exif-information. Do I need anymore parameters to leave everything else unchanged, like:
-keepdocsize : Resize bitmap function of the old and new DPI value
-keepcspace : Keep original color space if possible
-ratio : Keep the ratio for scaling

Or anything else? So, does jpegtrans automatically keep the color space, ratio and keepdocsize (the last one I do not understand).

I need to be sure!! Don't want to discover in 5 years that I lost information which I cannot recover.

Thank you very much!
Nico

[xnview]

Hi,

I use: nconvert -v -keepfiledate -jpegtrans exif *.jpg
to convert my holiday pictures without (!!) loss.

My question is: The only purpose is to rotate losslessly according to exif-information. Do I need anymore parameters to leave everything else unchanged, like:
-keepdocsize : Resize bitmap function of the old and new DPI value
-keepcspace : Keep original color space if possible
-ratio : Keep the ratio for scaling

Or anything else? So, does jpegtrans automatically keep the color space, ratio and keepdocsize (the last one I do not understand).

I need to be sure!! Don't want to discover in 5 years that I lost information which I cannot recover.

Thank you very much!
Nico

No need to other parameters, but as i said often it's better to try on a copy folder first...

[Guest]

No need to other parameters, but as i said often it's better to try on a copy folder first...

I am slightly confused, because also the pictures that are already horizontal (no need for rotating, EXIF says horizontal is okay) seem to be rotated !!

Their file size definetely slightly decreases.

I've tried it manually with xnview, and automatically rotated pictures end up with the file size which I get after rotating the (correct) original 4 times.

Note: The pix is dividable by 4 in both height and width!

Thanks for a short answer!!

Best regards,
Nico

[xnview]

No need to other parameters, but as i said often it's better to try on a copy folder first...

I am slightly confused, because also the pictures that are already horizontal (no need for rotating, EXIF says horizontal is okay) seem to be rotated !!

Their file size definetely slightly decreases.

I've tried it manually with xnview, and automatically rotated pictures end up with the file size which I get after rotating the (correct) original 4 times.

Note: The pix is dividable by 4 in both height and width!

Thanks for a short answer!!

Best regards,
Nico

Could you send me a sample, please?