Frederik Steinmetz demonstrates how to harness some of the most common features of After Effects to create seamless texture blocks rather than using Photoshop, and raises some great points as to why you may want to consider AE for image manipulation work.
This gradient caused by a less than optimal lighting situation can be easily fixed with the technique described in this Quick Tip by Frederik Steinmetz. Use After Effects to correct the lighting on your textures
Frederik notes that After Effects does have the ability to replace the image and still have the effects follow through, making it much simpler than Photoshop to do the same thing on more than one image. Very few filters or effects in Photoshop make use of the PS “smart” filter or adjustment layer category where you can change the attributes of the effect at any point. After Effects actually does this quite well by just stacking effects in the panel, allowing you to change, tweak, and edit effects at any time.
Check out the post which explains Why AE Might Be Better Than Photoshop for Tileable Textures here.