jpegstripper

dwing's ujpg is good, but it is not open-sourced, and ujpg will strip out Adobe APP14 marker from JPEG YCCK image, which is vital to those files.
So I wrote my own, modified from my own jpginfo.

Download source+binary: jpegstripper.zip

Changelog:
[20140316]
- print filename in error messages
- treat ncomp=3 without RGB compid as YCbCr
- add YCCK marker fixing switch "-y"

jpginfo

When I tried to debug why mozjpeg jpegtran segfault with certain files, I have a look on libjpeg and nanojpeg source code, and write a JPEG information tool which returns image resolution, number of color components, color space, and file type.

Download source+binary: jpginfo.zip

Changelog:
[20140316]
- print filename in error messages
- treat ncomp=3 without RGB compid as YCbCr

repng2jpeg 1.0.4.2

repng2jpeg is a simple image resizer using libgd.
Supported Input: PNG, JPG, GIF, BMP[added in 1.0.4.1]
Supported Output: PNG, JPG, GIF, BMP[added in 1.0.4.2]

Download Win32 Binary: repng2jpeg-win32.zip
svn source repository: http://rtoss.googlecode.com/svn/repng2jpeg/

Change since 1.0.4:

• [1.0.4.2] added BMP writing support (requires libgd 2.1.0-alpha)
• [1.0.4.1] added BMP reading support (requires libgd 2.1.0-alpha)