One Pass : -jpegtrans exif & Resize

[zebulaon]

Hi,
Firstly, congratulations and thank you for this remarkable program.
That is my question: I'd like in one pass return and resize multiple images in a folder source. (For the rotation I'd like to use the Exif information.)
Here is my command line: (-keepfiledate -jpegtrans exif)

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"E:\Program Files\nconvert\nconvert.exe" -q 90  -out jpeg -o "C:\phpwebgallery\DirWorkingFTP\%.jpg" -ratio -rtype lanczos -rflag decr  -resize 800 800 -keepfiledate -jpegtrans exif C:\phpwebgallery\DirWorkingFTP\testing\pwg_high\*.jpg 

My problem is that only pictures that are returned are resized, they are not returned resized. (They are ignored! nconvert says : NO NEED)
First is this possible? and if so, could someone fix command line syntax
Thank's

[marsh]

I don't see Exif information listed as part of normal image processing functions. Please note that jpeg operations are special. -jpegtrans and -jpegcrop write to files directly (cf. warning dialog in GUI version).

nconvert.exe -jpegtrans exif test.jpg
(directly rotate original according to exif tag)

[maesehn]

Hi,
same problem here!
My objective is to reduce in size multiple pictures at the same time to send them easily by email. Pictures are all original, straight from the camera!
Because i'm new to nConvert, i tried to add each command line switch one at a time to understand exactly how it works. Everything worked fine until i add the “-jpegtrans exif” switch:

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nconvert.exe -ratio -resize 2048 2048 -jpegtrans exif -keepfiledate -rmeta -o photo-##.jpg *.jpg

The result of this command is:

• - all the output pictures are renamed (good)
  - none of them are resized (bad)
  - none of them have their metadata removed (bad)
  - pictures that have to be rotated are rotated (good)
  - only the ones that were rotated kept their timestamps, not the other ones (quite bad)

I tried to move the “-jpegtrans exif” switch at different positions (i read about that in another post) but none of my tries were successfull…

My question is: Am i doing something wrong (if so, can anyone help me please?)
or will i have to (as zebulaon suggests) do multiple passes to obtain my reduced pictures?

Thanks for any help!

PS: i spend hours to guess how to add leading zeros on the outpout filenames, it should be added to the help file (OK, i will tell about this in the documentation section).

[marsh]

Because i'm new to nConvert, i tried to add each command line switch one at a time to understand exactly how it works. Everything worked fine until i add the “-jpegtrans exif” switch:

Jpeg lossless transformations directly write to files, and should be seperate from standard image manipulations like resize, crop, or rotate. original-file>original-file vs. input>output-file.

[maesehn]

Problem #1

Jpeg lossless transformations directly write to files

I didn't understand what you meant until i made some more testing:
Because i created output files with “-o photo-##.jpg”, the original files remained in an absolutly virginal state! (That's why your answers made me puzzled!) So i tried this simple command you gave in post #2:

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nconvert.exe -jpegtrans exif *jpg

and you're right: the pictures that have to be rotated are rotated and they are overwrited!
That's problem #1 (helmut talks about it in his new topic): unlike the other switches, “-jpegtrans” doesn't need for the “-overwrite” switch, it just does it! by default! But if an output name is specified, the lossless transformation is made on the output file not on the source… All that is really confusing wether you are a geek or a newbie.

Problem #2
Few switches are compatible with “-jpegtrans”, i mean, let's remember my complete command line in post #3: as soon as i added the “-jpegtrans” switch, “-resize” & “-rmeta” didn't work anymore and “-keepfiledate” gave some strange results…

Solution
So, as for now, it seems that there is no way to “lossless-rotate” and resize in one and only pass.
The better solution i found is to run two commands one after another, as in the exemple below:
- first command to run (lossless rotation)

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nconvert.exe -jpegtrans exif -keepfiledate *.jpg

- second command to run (reducing file size)

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nconvert.exe -ratio -resize 2048 2048 -keepfiledate -rmeta -o photo-##.jpg *.jpg

It works fine but it's not user friendly, maybe we could add this to the bug/feature request list?

[xnview]

Problem #2
Few switches are compatible with “-jpegtrans”, i mean, let's remember my complete command line in post #3: as soon as i added the “-jpegtrans” switch, “-resize” & “-rmeta” didn't work anymore and “-keepfiledate” gave some strange results…

Ok, but when apply lossless operation? Before all others??