Transparency in Bitmap Images in InDesign
bitmap5
You can save Bitmap images as TIFF, EPS, or PSD (Sandee will be happy to note that I virtually always would use TIFF or PSD). If you import a Bitmap image into InDesign, the white pixels are treated as transparent areas and the black pixels knock out any color behind them.
Here’s a Bitmap image that I created by taking a grayscale picture, choosing Image > Mode > Bitmap in Photoshop, then choosing Halftone Screen to fake the look of a low-lpi line screen. I saved it as a PSD and imported it into InDesign.
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You can see that the white pixels are transparent. The Separations panel easily shows us that it is knocking out the green areas behind it.
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bitmap3
bitmap4
Of course, when working with Bitmap images, you typically need them to be around 600-800 ppi for newsprint or low-end uncoated jobs, or 1,000-1,500 ppi for higher end jobs on coated stocks. Otherwise, you’ll see jaggy edges.
Bitmap images are great for special effects, especially when simulating low-frequency halftones!
David: “Sandee will be happy to note that I virtually always would use TIFF or PSD”
Well, in the spirit of Sandee’s EPS post: what purpose does the TIF format serve anymore — if you’re using ID? It’s far more practical to work with PSD files and place them natively in ID, than to make intermediary TIFs, like we had to do back in the bad old Quark days. So — what’s up with TIF in our modern ID world? Why not just fogedabautit?
I have been wondering the same thing lately, Klaus. Can anyone enlighten me/us?
We fought the TIFF vs. PSD wars a while back in an earlier post.
I still prefer TIFF because I like the flexibility and the idea that it’s more likely that there will be TIFF readers 20 years from now than PSD readers. However, to be honest, I find myself using PSD increasingly, as each year goes by.
For the self-taught, intermediate-level user … how do you handle the RGB/CMYK issue. I was told that is one of the reasons to save to TIF since you save the PSD as RGB and the TIF as CMYK. Sorry for a beginner level question, but your blog has been the best thing that’s happened to me in ages.
Hi Dawn. Actually, you can save either TIFF or PSD in either the RGB or CMYK format. It makes no difference. InDesign reads both. So no, color mode isn’t a reason to choose one over the other.
David, with the ever-increasing success of Photoshop all over the world, I find the notion that we would not be able to read PSDs in 20 years to be totally absurd. So far, after 18 years on the market, Adobe has made sure that all ancient PSDs will open just fine in each new version of Photoshop. Why should Adobe suddenly go crazy and change this backwards-compatibility? And if I really had to be future-paranoid at some point in, well, the future, I could make an PS Action and convert all my PSDs into TIF, GIF, BMP, whatever in some hours. As could everybody else. So let’s leave paranoia to the paranoid — and stick to PSD! It’s a brilliant graphics file format.
OK, I now read through the whole PSD vs. TIF thread — there’s absolutely nothing there to convince me TIF has anything going for it anymore. To *only* use PSD for *all* bitmaps going into InDesign is a big efficiency factor. So David, I say you’re just an ol’ reactionary pining-for-your-Quark-days . . .
What are the pitfalls of saving as an EPS, as it’s Bitmap anyway, there’s no fear of re-opening will rasterise it, as it’s raster already, right?
What has everyone got against .eps that makes them want to stay away from it. Even over on the TIFF vs PSD thread there were people saying they stay away from EPS, why?
Eugene, for starter EPS is complex PostScript code — which will only print on PS printers, on non-PS printers only the low-res, crude preview will print. So for proofing on a low-cost inkjet printer it’s a no-show, unless you first make a PDF and print from Acrobat. And it’s also a very verbose format — i.e., size-bloated. And there are many flavors and dialects of EPS, due to its PS programmability, so even if one EPS opens fine in, say, Photoshop, it might totally trip up some other photo-editing or page-layout program. EPS has cost graphics folks a lot of unwanted gray hairs!
Interesting that the bitmap transparency in a PSD is only supported by InDesign — not QuarkXPress 7. (Bitmap transparency in a TIFF is supported, though this may be v7 only. You have to change the “Picture Background” color — new attribute in v7 — to None.)
Quark’s PSD Import filter doesn’t support bitmap mode; only grayscale, RGB/CMYK, index and multichannel.
I understand saving and using PSD files. That is on my list of favorite ID features (a very long list).
The folks who create/supply most of the graphics and photos for me have been saving files as jpg (lossy) and sending those to me until my message finally got through recently to save them as tiffs (lossless).
These files may need to be used by a lot of people with odd and assorted software and software versions for multiple purposes.
I am often a version ahead of the graphics guys with Adobe products.
So, is there a “best” format when graphics and pics may need to be used in microsoft documents (ick!!!), on the web, in ID, or anything and everything else that someone has come across, as well as both Mac and PC platforms (notice which of those I listed first)?
I work for a small publisher that localizes Japanese comics, which are 99% black and white, so I see bitmap images a lot. Even though I knew all the information that was presented this was a very nice article to read, as it covers a lot of areas that I only found out through a lot of experience. I still output as TIFF, even though my whole environment is Adobe based. It’s partly because of tradition (we’ve been doing this since Quark 5, and switched to Indesign at Version 2), and partly because not everyone here has Photoshop installed so it’s easy to preview the image on any computer if I have to.
Sometimes we get bitmap images as high as 2400 ppi! The screentones that get used in the artwork is so detailed sometimes that it can be easily mistaken for something outputted as grayscale. It’s pretty amazing what you can do with one color if you have enough dot coverage to work with.
The reason why people should consider using TIFF files is the ability to use compression. If you use ZIP compression on a TIFF, which is lossless, the file will be about 1/4 the size as PSD. Go ahead and try it. This is a big deal when your dealing with dozens ( or hundreds) of images. You will notice the size difference more on color images than bitmapped or grayscal.
Please keep using Tif files !
The difference in files size is huge when working with large(r) files. I agree that having a layered PSD and the same file as a flattened Tif also takes up a lot of diskspace. But the processing speed of Indesign will greatly improve.
The test:
My layered PSD file takes up about 335 Mb (so, a large file). I don’t feel like placing this sucker in Indesign
When I save it as a LZW (losless) Tiff it takes up 4Mb !
Owkay, I agree that the layers are the cause for the big file. But even when I flatten my file the psd is larger (4,5Mb).
HOw can I save a PSD file in INDESIGN CS3?
thanks
Sara, you bring up a good point: I wish there were a way to export PSD files. Unfortunately, you cannot. But you can export a JPEG file; or a PDF file and then rasterize that in Photoshop. (But you lose all your layers.) You can also export to PDF, then open in Illustrator and export to PSD from there.
To correct something that was said earlier here… You have been able to use bitmap tiffs in Quark for many, many versions, going back to at least v3. Transparent bitmap tiffs are very handy, and there are certain situations where they are better to use than a grayscale tiff.