Image processing batch tool to resample images with YCbCr=4:4:4

I am looking for lightweight image processing tool that will resize images to JPEG in YCbCr = 4:4:4, that is, no chromatic subsampling. I am using this to generate square thumbnails.

I need 4:4:4 because I am not sure about the quality of 4.2.2 or 4.1.1 as they will have greater amount of artifacts,开发者_开发知识库 which will affect the quality of my thumbnails.

It will be run from a web server (ASP.Net MVC 3). Command-line tool, standalone application and libraries are all acceptable since it will run in separate processes anyway.

Anything out there except ImageMagick? I think it is too bulky.

Thanks a lot for answering.

Windows Imaging Component allows you to choose your own JPEG chroma subsampling option. See Encoder Options: JPEG Codec specific options: JpegYCrCbSubsampling

This is a very heavy-handed approach and requires a somewhat difficult learning curve. You may want to look for other options before delving into WIC.

IrfanView has an option to remove color subsampling. In JPEG save dialog, check "Disable color subsampling". This should store the JPEG with all channels in full resolution.

However, looking at its command-line option manual, I don't find any mention of this option. So, it may not be possible to automate or programmatically use this function.