Book Design and Imaging

Blurb Converts Grayscale to sRGB

Will it be the same result if I let Blurb convert my grayscale images to sRGB, or should I do it? It’s a lot of work since I’ve already laid out the book.

Thanks,
Steve

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Posted by
owleyes
Apr 7, 2008 4:48pm PDT
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owleyes
 

I don’t think Blurb will convert your images. Your images should be JPEG’s saved as sRGB color space. The answer is you do it.

 

Len 

Posted by
lcarreira
Apr 7, 2008 6:59pm PDT
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lcarreira
 

This info is in the FAQs. It sounds to me like Booksmart does the conversion. Is this not the case?

<currently>
Posted by
owleyes
Apr 8, 2008 6:52am PDT
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owleyes
 

oops. Here’s the rest:

<currently>
Posted by
owleyes
Apr 8, 2008 6:53am PDT
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owleyes
 

This isn’t working… One last try:

“Currently, black and white images are best loaded into BookSmart in sRGB color. BookSmart accepts grayscale images, but ultimately converts them to sRGB because darker shades of black are printed using four-color builds.”

Posted by
owleyes
Apr 8, 2008 6:54am PDT
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owleyes
 

Is there anybody here who’s made a book with B&W photos submitted as grayscale vs. sRGB, who can report on the quality or the difference?

Thanks,
~Steve

Posted by
owleyes
Apr 10, 2008 8:30am PDT
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owleyes
 

BookSmart is not a color savvy application. The sRGB profile is recommended because it is an inherently small color space; using it simplifies the conversation of image data into output values the Blurb presses can reproduce. Without an accurate print profile for soft proofing, however, the color management architecture of Blurb is virtually non-existent. It is a good idea to only submit grayscale images to Blurb tagged with the sRGB profile. If your grayscale image is “neutral” in hue, it will most likely appear a bit blue or green once printed; this color shift varies from print run to print run and, unfortunately, there appears to be some metamerism when grayscale images are printed on the HP presses (you’ll see a slight shift in color when the book is viewed under different lighting conditions). Metamerism is always more obvious in grayscale photographs made with color ink compared to full color images. You might want to consider toning grayscale images in Photoshop; give the images a color tint you like or think is appropriate. Converting an image file to a monoprint will help camouflage the inherent problems.

Posted by
BillKennedy
Apr 10, 2008 1:26pm PDT
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BillKennedy
 

Thank you. Your information is helpful and appreciated. However, I’m still wondering if “I” need to do the conversion, or if it will be the same if Booksmart does it. I want to know because If I need to do it, I’ll have to go back and lay out the entire book again.

Posted by
owleyes
Apr 11, 2008 9:58am PDT
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owleyes
 

Owleyes,

Yes, you need to convert *all* of your images to sRGB colour profile in image editing application (whether it can be Adobe Photoshop CS3 or similar application). If you use Photoshop, be sure to set sRGB color profile assigned AND save it as “high quality” to 12.

Posted by
brianbonitz
Apr 11, 2008 10:01am PDT
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brianbonitz
 

Hi Owleyes –
If you already have your book laid out and don’t want to go to the effort of reimporting new images I’d suggest you go ahead and order the book and see if you’re happy with the results. I work here at blurb, but please believe I’m not saying this just to get you to order a book :-). If your concerned about cost a good number of people order a small page number book, 20-40, pages as a hard proof as a good number of people are happy with the results.

If you are unhappy with the results I would open your images in Photoshop and translate to RGB and apply the sRGB profile. Also consider some of the tips that Bill describes.

The other posts here are correct- BookSmart will translate your GreyScale image back into an RGB image in the sRGB colorspace. sRGB is a smaller color space than say, Adobe RGB (1.2 mil to 1 mil colors approx), but really that doesn’t matter because when the book goes to print the final step is called a RIP… this is where it is actually translated to CMYK, or printed ink, which will get you around 400k colors on average. This is common for 4 color printing. Ink on paper can only represent a subset of what you can see in screen.

BillKennedy does a thorough job of outlining some of the challenges of printing b&w images in a 4-color process above. If you are interested in soft proofing using the color profile for the HP Indigo you can learn more about in this FAQ:

http://blurb.custhelp.com/cgi-bin/blurb.cfg/php/enduser/std_adp.php?p_faqid=75&p_created=1173745366

cheers – chad, VP design

Posted by
CapnScrappy
Apr 11, 2008 11:50am PDT
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CapnScrappy