I have been using Adobe Lightroom separately as a default corrective tool for exposure and white balance for both JPEG and RAW format.
However, I found out that my workflow was not quite effective as I have to use two different software to edit a single image. Then I figured out that my problem can be solved with Photoshop Camera RAW.
There are some settings required to enable all JPEGs file to be automatically open in Photoshop Camera RAW and if your Photoshop CS4 suite does not inlclude Camera RAW, you must install Camera RAW plugin first.
This is 3 simple steps on how you can automatically open JPEGs file in Photoshop CS4.
1. Goto Edit > Preferences and Click Camera RAW
2. Scroll down to JPEG and TIFF handling
3. Change default setting to Automatically open all supported JPEGs
You are done. Now you can automatically open all JPEGs file by default using Camera RAW. Simple right?