bitmap images

[mr greeze]

I'm looking for some help to create some rastered images. The effect i want to create can be seen on p27 of beast magazine issue 08. ([url]http://www.ths.nu/beast/)Sorry[/url] you'll have to look there but i can't find any examples anywhere else. I guess it has something to do with bitmaps but i have no clue how it works. Can anyone help me? thx a lot

[Gary Hummell]

Sorry my subscription lapsed. I am sure when you find an accessible example, there will be people here who can help.

[Colin Walls]

I'm not sure what you're after. I looked at this Web page and all I can see is a tiny picture of a cow.
Please explain.

[Rose_Tannenbaum@adobeforums.com]

When I import a bitmap tiff file into InDesign CS2, it looks and prints very bit-mappy. How should I import a 1200 dpi bitmap image? When I import grayscale tiffs, they are fine.

[chris@adsrus.com]

Is there any transparancy on the page?
I'm wondering because the "Transparency Flattener" may be kicking in, and depending on your settings, may be down sampling your image.

Chris

[Nini Tjäder]

1200 dpi sounds way too much. I guess you have then also scaled down the image when placing it? Have you tried reducing dpi to something more normal, like 300 dpi which in most cases - if not printing on special paper or so - is enough.

[Cindy_Johnston@adobeforums.com]

Nini,

Shouldn't a bitmap be half the resolution of the print divice? My image setter is 3,000 dpi so I make bitmaps at 1,500 dpi (toned images, though, at 300 dpi).

Cindy

[Nini Tjäder]

No. What the print-device is able to use in resolution is not all that interesting. Wahat is interesting is which kind of paper you print on and for which purpose. Granted, I have no idea which kind of products you produce. Usually 150 dpi images are enough for newspaperprint, 300 dpi images for magazines, and sometimes higher for coffee-table type of books.
I am no printing guru, but I know that 1500 dpi is way too much in most cases. More aobut printing form Indesig can be find in the pdf called Indesign CS2 Printing Guide which should be on your install CDs or can be found at Adobes website.

[Bob Levine]

For true bitmap images, sometime referred to as lineart, 1200 is
certainly about right.

Remember these images have only black or white info...no gray.

Bob

[Peter_Spier@adobeforums.com]

I think we are talking about lineart here, not continuous-tone images, in which case I believe Cindy is correct.

Question for Rose, what size was the original image, and it's mode before it became a 1200 ppi bitmap, and what method was used to scale?

You'd have better luck, for example upsampling a grayscale from 300 to 1200 and then converting to bitmap than doing the conversion and then upsampling, or even doing the upsampling as part of the conversion process.

Peter

[Nini Tjäder]

Ah line-art. Thought she said bitmap Tiff originally?

[Bob Levine]

Technically, the same thing.

Bob

[Peter_Truskier@adobeforums.com]

As far as the display is concerned, does it look bad with "High Quality" display performance option is chosen? As for the printed result, make sure you have the Print dialog box option under "Graphics" set to send "ALL" data, not "Optimized Subsampling."

[Rose_Tannenbaum@adobeforums.com]

Thanks for all these responses. The answer is: the display performance setting. It was set on "use view setting." When I changed it to high quality, it looked and printed fine.

I've been a PageMaker user for 15 years, plus several years using Quark, but I'm new to InDesign so I'm still learning the basics.

The original image was a 72 dpi jpg, which I saved as a grayscale tiff at 300 dpi, then converted to bitmap at 1200 dpi. I'll try upsampling first, then converting, and see if it's even better.

[John_Slate@adobeforums.com]

So this is a non-postscript printer issue?

Rose:

Generally speaking, you get better results in bitmap mode if you do a bicubic resampling of the grayscale to a higher resolution before converting to bitmap.

However starting at 72 and ending up at 1200 is a huge stretch... and probably not worth all the extra resolution. You can't get blood from a stone.

If you can, rescan original art at a higher resolution to begin with

[Klaus_Scharfenstein@adobeforums.com]

The original image was a 72 dpi jpg, which I saved as a grayscale tiff
at 300 dpi, then converted to bitmap at 1200 dpi.




Ok, if you're satisfied with that 1200 dpi bitmap image when finally looking at it in Photoshop then there's nothing wrong with that method. And of course: What that bitmap looks like in Photoshop in terms of sharpness should be the same when you print it from InDesign. In other words: There should be no »bitmappyness« in print that isn't present in the image either.

And I can't agree with Nini about the recommended resolution of bitmaps. I'd say that 1200 dpi of a bitmap image is absolutely OK. You may check ID's PDF settings for »Printing Quality«: It defines a downsampling to exactly that resolution for bitmaps of 1800 dpi or more.

Klaus

[Nini Tjäder]

Klaus - it depends on the content of the image doesn't it? In combination with the paper it is printed on. For instance if you print on newspaper stock, a resolution higher than 300 dpi is only a waste and does nothing for the quality of the image at all - it actually makes quality worse. But, as I said before. it depends on what is in the image and on which paper you are to print it too with what printign machine and printer.

[Klaus_Scharfenstein@adobeforums.com]

But, as I said before. it depends on what is in the image and on which
paper you are to print it too with what printign machine and printer.




Which obviously has totally been ignored when those sort of world wide accepted PDF settings for print quality were defined. How comes? Please just find me one print related PDF setting of any meaning where a bitmap downscaling to 300 dpi is specified.

There seems to be reason to believe that a 1200-dpi-bitmap when ripped to 300 dpi for printing makes a much better result than let's say a 600- or 450-dpi-bitmap.

[Bjorn_Ost@adobeforums.com]

Nini, your argument is only valid for continous tone images, a 1-bit image that needs to resolve fine detail is a different beast. Acrobats preflight even warns when lineart images is below 1000 dpi as a default.

PS. As I understand bitmap, all images (except vector) are really bitmaps technically speaking. In the beginning Photoshop called the true black and white mode 1-bit but in later versions the word bitmap has started to mean only the one bit variety. The .bmp in windows graphics format stands for just "bitmap" and can contain 1,4 and up to 32 bit information in it's bitmap.

[Klaus_Scharfenstein@adobeforums.com]

As I understand bitmap, all images (except vector) are really bitmaps
technically speaking.




No, I wouldn't say so. As far as I understand: A bitmap is a grid of bits, while a bit is a numeral from the Binary System and can therefore either have the value 0 or the value 1. So a bitmap consists of zeros and ones, where the visual conversion leads to a black pixel for every 1 and a white one for every 0.