Scanning: Those Irksome Dots
...specifications state that it should be 2" x 2" at 300 DPI.No matter how much I read about DPI/PPI/etc, I continue to be confused. If you are able to detect what I am doing wrong, I would be very grateful for your help. (Please note, I do not have additional desktop publishing software, such as MS Publisher or Photo Shop.)
I am using a Canon MP600 printer/scanner. I open the navigator to customize my settings, but if I set it at 2" x 2"/300 DPI, it only scans a 2" x 2" area of the cover. When I change the settings to the actual size of the cover (4.75" x 4.75"), I then try to resize the file to the editor's specs. The program I am using defaults to pixels as a means of measurement, and this really throws me. I have scanned the image at both 300dpi and 600dpi, and have tried resizing each to various pixel measurements (600 x 600, 864 x 864, etc; also 45%, 50%, etc.)
No matter what measurements I use when resizing the graphic, and no matter what my original DPI setting, my final graphic does not seem to meet the editor's specs.
Well, Barb, I'm not familiar with how your scanner works but I tried to resize on-the-fly with my own scanner and after some trial and error I managed to get that 2"x2" image at 300dpi. One problem you appear to have is that when you set the size to 2"x2" in your scanning software, you're changing the document size -- which tells the scanner how much of what is on the scanning bed should be scanned. In the case of the CD covers, the document size (which may have a different name in your software) should be around 4.75" x 4.75". It's the target or output size that you want to set to 2" x 2". In my own scanning software I had to do a preview scan first -- before that the target size option was greyed out for some reason. But after setting those two sizes properly, and scanning at 300dpi I got an image that meets your editor's specs.
You mentioned resizing the image but you don't say what software you used. Some good free image editors for Windows include GIMP, Serif PhotoPlus (certain older versions are free), and Paint.NET. You might consider getting one of those if you'll be resizing images a lot. And as for the image measurement defaulting to pixels, in your case you're looking for an image that is 600 pixels by 600 pixels. At 300dpi that would be a 2" x 2" image. And don't be surprised if the image looks huge on-screen. That's normal. As long as the image attributes indicate that it is two inches high and wide and 300dpi then you're OK.
Readers, do you have some more advice for Barb? If you have experience with her specific model of printer/scanner perhaps you can tell us what settings or controls to use. Share your own tips on scanning and resizing images.
Comments
A lot of people confuse dpi with ppi. Dpi is dots per inch and to get shades there has to be more dots fired on in that grid or lpi (lines per inch) If U have 300 dpi at 1 lpi U would have 300 dots to make a shade or 300 shade(in theory), at 300 lpi U would get 1 dot to make a shade and U would have ether black or white. but at 1 lpi the resolution would be low. Remember a dot is ether on or off to get a shade U need to have so many dots on in a given grid or lpi.
Ppi is pixel per inch, a pixel is different from a dot in that it has it’s own level of shade, each pixel can have 128 shade of gray (if you have it set at 8 bits per pixel), in ppi U do not need a grid/lpi becuase all the pixels/dot can make there oun shade.
On monitors the gun hits the phos. dot and it glows the more intense the electronic beam hits the dot the brighter it get hence the 128 shades.
On a printer there are only dots and dots are ether black or white on or off. To get shade they have to be group in a way so U can turn on and off these dots to make a shade. (theres no gray)so U can see that the more line U have per inch the less dots U have to make a shade at a given dpi.
Plate makers and image setters have a lpi and a dpi listed for them and you can change them. On a ink jet printer it is set and they really don’t say what the lpi is just dpi.
OK
Now I have a question is there a way to get the lpi of a inkjet printer