Question: I am looking for a way to make the image below straight - like in the line. To make it clear - it would be a tattoo template, which will be placed *around* my upper arm.

[![logo](https://i.stack.imgur.com/zDVLA.jpg)](https://i.stack.imgur.com/zDVLA.jpg)

Is there any solution of this, in Photoshop?

Answer: 
It won't be perfect but you could use a Polar Coordinates filter (*Filter → Distort → Polar Coordinates...*) set to "Polar to Rectangular" on the image:

[![](https://i.stack.imgur.com/HK5db.png)](https://i.stack.imgur.com/HK5db.png)

The result will be "straight", but will be distorted so you'll at least need to adjust the height to compensate. This is after transforming the layer to 50% height:

[![](https://i.stack.imgur.com/PfYYc.png)](https://i.stack.imgur.com/PfYYc.png)

With a further bit of correction using a mesh warp (*Edit → Transform → Warp*):

[![](https://i.stack.imgur.com/uNBxL.png)](https://i.stack.imgur.com/uNBxL.png)
This can be done. But not done very accurately. There will be some warping and distortion when you straighten it out. That said, here's what I would do.

1. Cut the piece into 3 separate pieces using your favorite selection method. I suggest the pen tool, but you don't really need to be that accurate.

[![Selection](https://i.stack.imgur.com/CS9E0.jpg)](https://i.stack.imgur.com/CS9E0.jpg)

2. Put each piece on it's own layer.
3. Then use the Puppet Warp Tool (Edit > Puppet Warp) to straighten each piece out. Add points along the curve and align the points and image into a straight(ish) line.

[![Add Points](https://i.stack.imgur.com/JHyvf.png)](https://i.stack.imgur.com/JHyvf.png)

4. If you need to, you can align the layers into one long line.

[![enter image description here](https://i.stack.imgur.com/wdFRi.png)](https://i.stack.imgur.com/wdFRi.png)