Convert multiple images per command line
Use nconvert with its infinite possibilities.
NConvert is a batch utility for converting graphic files.
- Import about 400 graphic file formats
- Export about 40 graphic file formats
- Multipage TIFF, Animated GIF, Animated ICO support
- Adjust brightness, contrast...
- Modify number of colors
- Apply filters (blur, average, emboss, ...)
- Apply effects (lens, wave, ...)
- And many many other things
Read this User guide for some examples to start.
I uploaded the full help file on pastebin to see what parameters are available
Note: A graphical front-end using nconvert is XnConvert
To answer hemalshah' initial question
- download nconvert and place it somewhere
- create a .cmd in the same folder and copy&paste the following command
- Customize the path to your own .tiff image and execute the batch file.
This will create a new mysource_1.tiff file in the source folder (use
-overwrite to replace the original)
nconvert -out tiff -multi -dpi 100 -c 4 -keepdocsize -keepfiledate mysource.tif
- this can easily be expanded to convert thousands of files at once.
Nconvert understands textfiles with image paths as input
-out tiff -multi is necessary to tell nconvert to produce multi-page TIFF files
-dpi 100 obviously sets the new DPI
-keepdocsize preserves your page height and width
-keepfiledate preserves the original create date
-c 4 sets the compression method. I recommend ZLIB since it produces the smallest files
Other compression methods
1 (Rle), 2 (LZW), 3 (LZW+Prediction), 4 (ZLIB)
5 (CCITT G3), 6 (CCITT G3-2D), 7 (CCITT G4) only B/W
8 (JPEG) only 24/32 bits
I separated the output tiff into single page tiff files to see if all pages are set to 100 DPI. As the screenshot proves, nconvert will solve your issue.