how to convert rgb black in image to 100% black

[mazengh]

I have a lot of rgb images that contain black text (as a raster with colored images) and I would like to convert everything black to 100% K in cmyk mode. Is there a way to achieve this?

Thanks in advance.

[jay12345]

I have a lot of rgb images that contain black text (as a raster with colored images) and I would like to convert everything black to 100% K in cmyk mode. Is there a way to achieve this?

Thanks in advance.

I have recently purchased Alwans ink optimizer and have been playing around with it's ability to do this. As long as the text is still vector it can convert the rgb black to k. It's an awesome feature but it is a pretty costly product. If you wish you can pm me and I will run the files through it for you.

[DCurry]

Convert to CMYK using Maximum Black Generation. Here's a couple of threads that address this issue:

Fixing 4c Black Text in Flattened TIF Files

Retaining Blacks

[mazengh]

I have tried the maximum black generation fix. it works well but as stated in the previous thread it ruins colored areas on the image. they mention a way to overcome this by generating a mask but i don't understand how.

[Stephen Marsh]

I have tried the maximum black generation fix. it works well but as stated in the previous thread it ruins colored areas on the image. they mention a way to overcome this by generating a mask but i don't understand how.

Is the text "isolated" and or easy to select, or is sitting on top of the photo? Can you supply a crop of the image?


Stephen Marsh

[mazengh]

It's 200 books i have to scan and print. there are all different kinds of scenarios. so i was thinking maybe there's a way to convert using an icc profile that would convert all rgb blacks to 100% k

[Stephen Marsh]

It's 200 books i have to scan and print. there are all different kinds of scenarios. so i was thinking maybe there's a way to convert using an icc profile that would convert all rgb blacks to 100% k

How will you be printing these books - composite (digital) or separated (press)?

There is no magic answer or solution for scanning in 200 books with X amount of pages per book and automatically colour separating only the text elements differently than photographic elements...it is all pixels and the only difference in the pixels is the darkness.

Do the photographic elements or non text areas have a dark point similar to the text, or are they all lighter in tone? In other words, is the text the darkest element on the page?


Stephen Marsh

[mazengh]

It's all cartoonish drawings. No skin tones or color critical area but with the maximum black gcr the colors become way off. If I can convert all blacks to 100% k I should be ok even if there are darker black points than the text. I will be printing sheetfed offset.

[Stephen Marsh]

It's all cartoonish drawings. No skin tones or color critical area but with the maximum black gcr the colors become way off. If I can convert all blacks to 100% k I should be ok even if there are darker black points than the text. I will be printing sheetfed offset.

Will your scans have the darkest areas of text and linework as pure black 0r0g0b, or will they be more like 12r17g14b?

What CMYK space would you ideally be converting to? Fogra 39? GRACoL? SWOP?

I presume that you would like the cartoon and text elements to have 100K with no CMY tints under the K? EDIT: If these are scans of printed work, I presume that the colour comics have a halftone dot? if so, will you be de-screening these scans to avoid moire when you rescreen and output new separations to plate?

What version of Photoshop do you have (as this may take an action run in batch mode, over and above the base profile).

Can anybody reading this topic thread create and share a "proper" CMYK ICC profile that does a similar thing to the old legacy Custom CMYK method of Photoshop Max GCR (0cmyk whites, 100K only "four colour" blacks)?


Stephen Marsh

[mazengh]

not sure if the darkest areas of text and linework are pure black 0r0g0b or 12r17g14b. I will double check and update. Ideally I want to convert to a fogra39 based profile.

"I presume that you would like the cartoon and text elements to have 100K with no CMY tints under the K? EDIT: If these are scans of printed work, I presume that the colour comics have a halftone dot? if so, will you be de-screening these scans to avoid moire when you rescreen and output new separations to plate?"

correct...

I have photoshop cs 5.5