I saved an image of an iPhone from Google and when I opened it in Photoshop, it had ruler marks set in place around the phone. I've never seen or even heard of such a thing before. I thought it was my doing at first but I re-opened the image again and the ruler marks were back.
How is it possible to embed ruler marks into a .jpeg image?
When an image is saved in Photoshop as .jpeg, .png, .tiff, etc. The file will also save the ruler (better known as "guides") information within it. I think Photoshop saves that info in a small portion of the file called metadata if I remember correctly.
I was surprised when I saw this too, however it turns out to be a new undocumented feature in CC 2014 - The data is stored within the jpeg metadata, visible from the file info pane. Under the advanced tab, you can view the property tree, and all the contained datalumps. By extension of this, there is word that Adobe are planning to add in a similar feature for embedded colour profiles.
[E: 20-07-14] - After testing this, it appears that ruler guides can be embedded in an incredibly simple way. Rather than selecting "Save for Web" simply select "Save as" instead as your export method, and select jpeg from the format dropdown. If you close and reopen the file to check, gridlines will be automatically loaded from the jpeg.
ADOBE PHOTOSHOP CS6 on Windows7 64bit
When working with .PSD files, guides are saving automatically (if you've used guides in your design) when you are saving the file as a .PSD.
If you exported an image (File>Save for web) from a .PSD file, guides will not save with the image file.
If you need to save guides within an image file(I have tested this only with .JPEG format.Try other formats yourself.) you have to open the image with photoshop and then add the guides as you require and then save(ctrl+s) the image.
Re-open the saved image with photoshop, you will see the guides also have loaded with the image file.
note: You can press Alt+Ctrl+; to show and hide guides.
Thanks!
