Pedro55 wrote:Hi.
Thanks also JoeyB. Didn't really know the technical difference between B+W and Greyscale. Will give both approches a try and see what the results are.
For most practical purposes when using a graphic editor the difference between the two terms won't matter too much. That's because when you use a graphic editor or a plugin within that editor and choose an option to remove the color from your image because you want what's known as a black and white photo, the filter or filters you will use will generally be labeled "Black and White" or B/W or B&W. That's because that is the distinction that almost everyone except techie people use and because that's how people have always interpreted the look of a photo when it doesn't contain "color".
But when you use a scanner to scan a color image you will find that the scanner interface that opens gives you a dropdown or a radio button selection for you to select how you want the image scanned, and the options are Color, Grayscale, and Black and White. And the difference in output is radical. That's because actual Black and White means you get a scan that only has two available color values - black and white, with no gradations between them. Examples of using that choice is for scanning text or simple line drawings, where you expect - and want - the text or lines to be black and the background to be white.
However, when you look at a "black and white" photo, you see much more than either true black or true white. You see many, many gradations - depending on the subject of the photo - between pure black, through a whole range or scale of gray values, and on to pure white. Put simply, you're seeing a whole range - or scale - of gray values starting from the darkest gray (black) to the lightest value for gray (white). That's why it's called "grayscale", because it can scale through all of those values. That's as opposed to the abrupt transition from pure black to pure white with no other values in between which is what the "Black and White" option on your scanner interface provides. And the reason I pointed out the difference was because you said you were thinking of scanning in "black and white."
But, as I said, while you need to be aware of the difference between those two terms to select the proper option for you scanner when scanning a color photo, the term "Black and White" in a graphic editor or plugin filter will almost always provide a graduated, greyscale type of image which is what is commonly known as a black and white photo.
By the way, that's one area where scanner software uses the correct terms for what your output will be. One term they always get wrong is the box provided where you can set what the scanner will always call "dpi". Scanners, and software editors, cannot set a DPI value. That's because DPI refers to "dots per inch," and that's something that is a printer specification only and depends on the specs of the printer and how it lays down ink. And those specs are determined solely by the printer manufacturer. What that option actually sets - despite what it says - is PPI (Pixels per Inch), which is information embedded in the image which tells the printer how many pixels of your image to print on each inch of paper when you send the image to a printer. That's why PSP or any good graphic editor only has an option in the Resize dialogue to set PPI, not DPI.