Photoshop rendering and cropping can be done in a few ways, this guide will teach how to crop people, objects and cars (scroll down for details).
Step 1. Open your image (or import it)
I will be using a photo (by Elorine) that is initially 1200w x 1600 pixels but I am going to scale it up (to 1800w) before I get started to expand every pixel and to get as much detail as possible.
Next you just need to duplicate the original layer (right click the layer in the layers panel and click duplicate/ or copy all and paste).
Step 2. Use the Shape Path tool to create shape outlines around your render
Select the pen tool in the main tools area and then start to outline your object or person that you want to crop. When applying your points remember that removing more background is better. If you’re tracing a rough or detailed item just remember it’s fine to simplify the selection around it and smooth it out (like arm hair or tree bark). I suggest making the shape somewhat opaque so that you can see through it and make fewer mistakes.
Photoshop Note: This is a good way to practice using the pen tool (which some might find tricky to use at first).
When I first started using Photoshop I was convinced that the polygon and lasso tool were essential for cropping but found myself using the pen tool to create paths because of the many times I would accidentally mess up my crop selections. With shape paths you can tweak your edges, fix your mistakes and make your crops even more accurate.
Step 3. Selecting Shape Paths and Removing Negative Space
Remember to create shape paths for the inner cropped portions, like in the statue’s case his hair and arm have a negative space I have to create shapes over to crop out. To easily zoom in and out of your picture while working with your pen tool I would suggest holding the Alt button with the mouse’s scroll wheel. I created the outline around the statue in my test picture by making two seperate shape paths around the figure on each side of the background.
After your backgrounds are covered with shape paths you’ll want to either merge them all (in later versions of Photoshop you just go to the layers menu and select the shape layers and press Control + E) but if you’re using earlier versions of Photoshop then you’ll want to just select each path by pressing Control + the Shape Layer name area.
After you selected your shape paths you can start deleting the background and your figure or object will now be cropped entirely.
Step 4. Export your crop/render as a PNG or PSD
If you’re new to cropping and transparency then one thing you need to know is that PNGs and PSDs are the most handy ways of saving your transparent images. PNGs won’t cause any file loss and can be uploaded to image sites without problem, they don’t save layers so you’ll need to use PSDs to have all your layers intact. One last time you might do before saving is trimming your canvas by going to Image > Trim and you can get rid of excess transparent document space. Lastly, make sure your original layer is hidden.
To save your image as a PNG go to File > Save for Web (choose preset: PNG-24)