Bitmap vs. Vector profile patches

[abccolor]

I have an elementary question for which I am looking for a colegiate answer. I need to know the possitive and negative effects of using bitmap profile patches vs vector. Thanks

 

[ColorGeek]

I don't think there is a difference. The patches themselves are single color so whether they are vector or raster doesn't matter. For what it's worth products like Monaco Profiler, Profilemaker, and ColorPort all generate raster test charts. The only thing that would be damaging is if these patch charts were assigned or converted using existing profiles.

 

[abccolor]

I revisited Profilemaker to confirm its ability to generate both raster and vector versions. Both prints are visually the same, but I still wonder if the eventual rasterization (at the RIP) of the vector artwork creates a difference at a deeper level.

My initial concern stems from the ECI2002CMYKi1 raster chart which was provided with Profilemaker. The chart is extremely low resolution.

I will be moving forward with the new Raster chart I generated unless, I hear some more information about vector charts.

Thank you.

 

[Mark Stegman]

Bitmap Vs vector profiling target

Bitmap Vs vector profiling target

Why does the resolution matter? They are just squares of flat colour. Making a higher resolution file will just take longer to process. If you want to test it just chnage the resolution in Photohop but be sure to use Nearest Neighbour so there won't be any dithering at the edges. it's the PHYSICAL size of the patches that matters. They have to be big enough to ensure the measurement device doesn't go over the edge and into another colour.

 

[abccolor]

Exactly. I have found the route of my initial problem. The raster version I was originally provided was corupted by either a reduction in resolution or compression. The squares of flat color, were artifacted and poluted with other colors. Once I stepped back and created my own with the Measure Tool, I now have a good file..... This still leaves us with the question as to why manufacturer's suggest the bitmap version of the patches.

Thank you both for your help.

 

[Lukas Engqvist]

Some rips can be configured so that vector and pixel data are treated differently, with todays deigns involving transparency that would be unadvisable... but it is a potential error and if you RIP has the option, chack that raster and vector data have same colour managing policies.

 

[TerryWyse]

I have an elementary question for which I am looking for a colegiate answer. I need to know the possitive and negative effects of using bitmap profile patches vs vector. Thanks

Short answer: no difference.

Longer answer:
AFAIK, all profile testcharts tend to be raster-based images. Even if there's the option to save the chart as EPS or PDF, I'm reasonably sure it's still a raster image in an EPS/PDF "wrapper".

The only caveat with raster charts would be altering the resolution using interpolation (naturally, you should never *scale* a chart). If you feel you need to alter the resolution of the chart, always use "nearest neighbor" interpolation otherwise the anti-aliasing effect that occurs with other methods could possibly cause problems along the patch edges, resulting is possibly bad measurements or mis-reads with instruments like the EyeOne. Instruments that use precise x/y patch alignment would generally not be affected by anti-aliasing along patch edges.

Terry

 

[Stephen Marsh]

On a "good" RIP, there should be no difference.

On a "PoS" RIP, there will be a difference - see the attached scan.

These patches are crops from a full sheet, I have simply moved them together to save on the file size.

The original was a PDF containing raster and vector elements, the PDF did not have any ICC profiles and it was printed direct from Acrobat Reader 9 to our crappy Xerox 5065 with CommandWorkstation front end and Fiery RIP. This is a PostScript print, not PDF print engine.

As you can see, whether it is CMY, K or CMYK combos - the vector and raster are different tones, when they should seamlessly blend together.

If I recall correctly, even the Altona test suite has tests for inconsistent processing of raster and vector data.


Regards,

Stephen Marsh

 

[Lukas Engqvist]

With that rip i'd print all as raster ;p

 

[Bbeens]

As mentioned above, I would check for any differences in color handling from Raster to Vector color spaces. Some Rips allow for different curves for each incoming color space (CMYK Vector vs. RGB Raster, etc). Although I would imagine you shouldn't have color corrections applied while profiling. I have also found several of the customer I support will turn off color management for their vector files and only apply ICC profiles to their raster data. This can be confusing when files contain both raster and vector data elements.

Bryan