Looking for freeware to batch resize images.

[GoldThreader]

I want my images on my E-reader to be re-sized to my e-readers resolution but I need the program to recognize and split double page images as well i.e comics ect.

[DSpider]

Scan Tailor if you want to split them. Maybe you can try outputting a lower DPI than 600... (with a DPI calculator, perhaps?). If you wana use it on comic books, set it to grayscale. In colour they would just take up more space - especially if you're reading it on the current E-Ink technology (which is monochrome).

If lowering the DPI doesn't work, Irfanview can also batch resize.

[kacir]

Originally Posted by GoldThreader

I want my images on my E-reader to be re-sized to my e-readers resolution but I need the program to recognize and split double page images as well i.e comics ect.

imagemagick
Imagemagick is the most powerfull commandline image manipulation program.
Runs on all platforms: Windows, Linux, BSD, mac, ...

[GoldThreader]

Originally Posted by DSpider

Scan Tailor if you want to split them. Maybe you can try outputting a lower DPI than 600... (with a DPI calculator, perhaps?). If you wana use it on comic books, set it to grayscale. In colour they would just take up more space.

If lowering the DPI doesn't work, Irfanview can also batch resize.

This program batch resizes images but I couldn't figure out how to get it to split double pages while doing that. I am not sure what you mean by DPI either. I was hoping for something that has a setting like Calibre where it it would split them automatically if the file is too large. I believe the default for Calibre to do so is 260KB.

[GoldThreader]

Originally Posted by kacir

imagemagick
Imagemagick is the most powerfull commandline image manipulation program.
Runs on all platforms: Windows, Linux, BSD, mac, ...

I couldn't figure this one out at all it only lets me pick from a single image no options or anything either. Maybe I'm missing something but seems like this can only edit single images.

[DSpider]

Originally Posted by GoldThreader

This program batch resizes images but I couldn't figure out how to get it to split double pages while doing that. I am not sure what you mean by DPI either.

I said that Scan Tailor can split them. The DPI settings ("Output Resolution") is the final step from Scan Tailor. If using a DPI calculator (link in my previous post) doesn't get you the right resolution for your device, Irfanview can also resize.

[atordo]

Originally Posted by GoldThreader

I couldn't figure this one out at all it only lets me pick from a single image no options or anything either. Maybe I'm missing something but seems like this can only edit single images.

I'm afraid that for batch manipulation you must use the command line. Have a look at http://www.imagemagick.org/script/convert.php

[GoldThreader]

Originally Posted by DSpider

I said that Scan Tailor can split them. The DPI settings ("Output Resolution") is the final step from Scan Tailor. If using a DPI calculator (link in my previous post) doesn't get you the right resolution for your device, Irfanview can also resize.

This program is really useful my only question would be how do I get it to split the pages exactly in half? it keeps putting the split line in odd places.

[DSpider]

It doesn't matter if the divider is exactly in the middle or 50 pixels to the right, as long as it doesn't overlap any part of the text. The pages will receive special treatment later on when you choose the content and set up margins.

Just go through a book, will you? See if you like the result. For comic books you should choose "Color / Grayscale" at the final step.

[kacir]

Originally Posted by GoldThreader

I couldn't figure this one out at all it only lets me pick from a single image no options or anything either. Maybe I'm missing something but seems like this can only edit single images.

Imagemagick is like a programming language. You start a terminal on Linux or Command Line on Windows and you start typing commands, like this

convert escher01.png -quantize GRAY +dither -colors 16 -rotate "-90>" escher01.bmp

For details for this example see post https://www.mobileread.com/forums/sho...753#post818753
For description of the convert command see http://www.imagemagick.org/script/convert.php

I know it looks crazy, but convert command from Imagemagick package has *huge* number of options. It is like Photoshop you run in "blind" mode.
When you have tried an example and you know exactly what you want to do, you take a list of images and use a good text editor to make a program. Either a shell program convert_my_pictures.sh in Unix/Linux or a batch program convert_my_pictures.bat in Windows. You can then let it run and convert thousands of pictures.

So, in Windows you have lots of images, like
flower.jpg
animal.jpg
car.jpg
kid.jpg
and so on. So you make a list of images, by entering a directory with pictures and running command

dir /B > convert_my_pictures.bat

Then you use a powerful text editor to convert a list of file names to something like:

convert flower.jpg -quantize GRAY +dither -colors 16 -rotate "-90>" flower.bmp
convert animal.jpg -quantize GRAY +dither -colors 16 -rotate "-90>" animal.bmp
convert car.jpg -quantize GRAY +dither -colors 16 -rotate "-90>" car.bmp
convert kid.jpg -quantize GRAY +dither -colors 16 -rotate "-90>" car.bmp

Then you run the program.

In Unix/Linux/OSX you might write something like:

#!/bin/bash
for f in *.jpg
do
        convert $f -quantize GRAY +dither -colors 16 -rotate "-90>" $f.bmp
done

Imagemagick is THE most powerful program for converting images but it doesn't have an user interface you could click on.

If you want something with a nice clicking interface, try this: http://www.xnconvert.com/
xnconvert is a brother of xnview program - a very powerful viewer with lots of options.

[DaleDe]

Originally Posted by GoldThreader

This program batch resizes images but I couldn't figure out how to get it to split double pages while doing that. I am not sure what you mean by DPI either. I was hoping for something that has a setting like Calibre where it it would split them automatically if the file is too large. I believe the default for Calibre to do so is 260KB.

I believe Calibre can only split text data in files, not images. I really like IrfanView of resizing or manipulate a whole batch of images at once, much better and easier than anything else I have found. But scan tailor is better at splitting images into multiple pieces. Irfanview does not try an analyze the image itself.

Dale