Thousands of files: Bulk Brightness change for selected area only

[alanman111111]

I have thousands of files. Bulk Brightness change for selected area only. Please help a newbie.
how can i achieve this. ?
No cropping involved, just brightness adjustment for thousands of files for selected area only in the image.

[IrfanUserGuyxyx]

You could crop and save the portion of the image you want to brighten, brighten it, then paste it back into the original image, using watermark, at the original location. This is possible in IrfanView, but might be easier using Nconvert to do it with a batch file.

[j7n]

Does the selected area always have the same dimensions? You could automate the process using AutoHotkey using the custom selection dialog and a series of keystrokes. This method can only run at limited speed to make sure the script doesn't lose sync, and you need to be familiar with a programming language.

[IrfanUserGuyxyx]

Irfanview lists the size and position of your selection in the title bar:


nconvert has:

-jpegcrop x y w h : JPEG lossless crop
-crop x y w h : Crop
-brightness value : Modify brightness (-100...100)
-contrast value : Modify contrast (-100...100)

then

-wmfile file : Watermark file (Must be after other -wm commands)
-wmpos x y : Watermark position
-wmopacity value : Watermark opacity (0-100)

Choose output filename:

-o filename : Output filename
Use # to specify position of numeric enumerator
Use % to specify source filename
Use $ to specify full source pathname
Use $$ to specify source folder name
Use $EXIF: DateModified[date format] to specify EXIF date modified
Use $EXIF: DateTaken[date format] to specify EXIF date taken
Date format: Please check documentation of strftime

-out format : Output format name

two calls to nconvert for each file

nconvert -jpegcrop <x> <y> <w> <h> -brightness <value> -contrast <value> -o <output filename> <filename>
nconvert -wmpos <x> <y> -wmopacity 100 -wmfile <output filename> -o <finished image filename> <filename>

note: <output filename> and <filename> are the same for both commands