Has anybody looked at the alpha channels(?) in Photoshop? Message could be camouflaged and appended to the images?
So there are 54 photos that returned a positive? Check those photos' channels for camouflaged messages?
Are the photos Q posted .png or .jpg?
Sorry, I meant the ones that didn't come back negative in the steganon's post.
From adobe:
https://helpx.adobe.com/experience-manager/scene7/kb/base/transparency-alpha-channel/layer-transparency-masks-alpha-channels.html
unassociated alpha channel
RGB images with alpha transparency can be stored in two different ways. One way is to store raw RGB values and alpha values as separate and independent channels; this is called "unassociated alpha". PNG standardized on "unassociated" ("non-premultiplied") alpha so that images with separate transparency masks can be stored losslessly. Most image-processing programs stores images with unassociated alpha, to be able to manipulate RGB and alpha independently of one another, and not lose RGB data when zeroing out alpha.
pre-multiplied alpha channel
Another way is to store RGB values not raw, but premultiplied by corresponding alpha value, which is then called "associated alpha".
If an alpha channel is used in an image, it is common to also multiply the color by the alpha value. This is usually referred to as premultiplied alpha. "Premultiplied alpha", stores pixel values premultiplied by the alpha fraction. The alpha information of a pixel is not only stored in the alpha channel itself, but it is already "multiplied" into the red, green, and blue channel. Rendering software prefers associated alpha, because with RGB values already multiplied by alpha, less work remains to be done in real time when doing alpha blending. TIFF support both types of alpha, but are frequently mislabeled.