Quick solution, save it as a TGA and preserve the transparency, or choose 32 bit TGA, what ever option you get in the other app. Then photoshop will open it properly.
Actuallty scratch what I said, I am backwards in my thinking.
What app is she using? Gimp by chance or some other app. Does it have the ability to save the image as a photshop file format .PSD? If so you may want to do that.
Masks are sometimes not saved properly on PNG's since they cant handle layers.
A potential solutions.
With the mask applied do a copy and paste into a new image. In the new image you will have it no longer masked but only the visible portion of the original image is saved, then save that as a PNG.
PNG files can't store layer masks, just simple transparency.
But it sounds like one of your programs does not read PNG transparency correctly.
And some web browsers (esp. older versions of IE) can't render PNG transparency.
Thanks for your suggestion. I just found the problem!
The original image I received from my sister was a gray scale image, & when I ran my test, I guess I must have converted the one where I didn't use a layer mask to be an RGB image, or I must have converted the one with the layer mask to a gray scale image! Either way, both images that had masks were also both gray scale images! I just verified this by making the grayscale one RGB, & converting the RGB one, without the layermask, grayscale. It's grayscale that's causing the problem.
Once I converted my sisters image to RGB, everything worked fine. So I guess it's some issue with grayscale PNGs?
Hi Chris, thanks for the reply. It turns out there was another difference between the image that I didn't realize. The one that didn't display correctly was grayscale, & the one that did display correctly was RGB.
What I saw happening, incase you're curious, was I uploaded the grayscale image to my sister's WordPress website, using the WordPress GUI, which creates scaled copies of the uploaded images. For one of the scaled images, the entire picture became gray, & for the other picture, all the transparency became gray. But in all cases, the original always looked fine. When I save the files in RGB mode, I have no problems whatsoever.
No issue with grayscale transparency, Transparency cant be saved on a grayscale image, there is only black and white and shades of gray.
Are you sure about no transparency with grayscale? One of the images I'm talking about can be viewed here:
When I open this image in PhotoShop (or Gimp), & look at the Mode, Grayscale is checked. And in most programs I view it in on the Mac (including PhotoShop of course, Gimp, Firefox, Safari, and Preview) it displays with transparent pixels & when I view the image with IE on Windows 7, it displays correclty there too. There are only a few instances where the grayscale image doesn't display the way I was expecting. One of them is with the program "Graphic Converter", a Mac only program. And when it was giving me a problem on WordPress, it was only after WordPress automatically scaled it. The original grayscale PNG with transparency displayed fine in WordPress. Anyway, it's obviously not a problem with PhotoShop. It's something about how those other 2 programs deal with grayscale PNGs with transparency.