(Draft page, further information will be added)
The following SW packages were used in the evaluation:
I made an uncorrected scan with Silverfast and used it as reference for all profiling packages (beside Vuescan). The scan was done with 300 dpi, gamma set to 2.2 for the reflection target and 2.4 for the transmission target. All packages used the same target from Wolf Faust (http://www.targets.coloraid.de/) beside EZColor and WiziWYG which have proprietary reflection targets.
I generated (tried to generate) a profile with all packages. I assigned the profile to the original scan of the Faust target and converted the RGB File to Lab. For this I used ColorLab from GretagMacBeth (Download of ColorLab). After this the scan (Lab format) was compared to the target data and deltaE was computed. I used two different tools for this and both generated similar results. One was the MeasureTool from the ProfileMaker 4.1 from GretagMacBeth. The other two was the profile checker from the Little cms profiler package and IPhoto (Homepage) .
I know deltaE is just one parameter to judge a profile, but I started with this and others may follow.
During the evaluation I had several problems with the different packages. It's currious that just commercial packages showed problems.
- EZColor generated profiles which contained tags which are not compliant to the ICC specification. This lead to the situation that the Little cms profiler package could not work with these profiles. ColorLab and IPhoto seemed to have no problem.
EZColor could also not be used with absolute rendering intend in ColorLab. The result was a all blue picture.
- I was not able to generate a transmission profile with WiziWYG because I found no way to enter the data for the target. Somehow the program expected always propriatary files (extension wyg). The documentation claims that you should be able to profile transmission targets with targets from other vendors.
- Also with Vuescan I was not able to generate a transmission target, because it always said that the scan is not aligned or so and after 30 min trying hard to get rid of the error message I stoped.
- ColorLab also rejected the Vuescan profile
The two following diagrams show the results for the Average deltaE and the Max. deltaE. The results are from IPhoto (which used perceptual rendering intend). The other evaluation tools showed similar results but did not work with every profile. Please not that I added perceptual just because EZColor profile did not work with absolute colorimetric.
Results for reflection target (perceptual rendering intend)
Results for transmission target (perceptual rendering intend)
Results for reflection target (absolute colorimetric)
Results for transmission target (absolute colorimetric)
The following attributes are not necessarily a measure of quality (large tables do not mean good precision) but may give some insight in the quality of the SW (flaws in the profile) and limitations (8bit tables can not meet the precision of a 16bit table).
|Evaluation of reflection profile||
|AIM||0,60/0,25/0,02||0,22/0,73/-0,18||0,12/0,02/0,95||4096 Points||4096 Points||4096 Points|
|WiziWYG||0,60/0,24/0,01||0,29/0,76/0,00||0,07/0,00/0,81||256 Points||256 Points||256 Points|
|ProfileMaker 4.1||0,62/0,23/0,00||0,21/0,76/0,00||0,12/0,00/0,82||515 Points||515 Points||515 Points|
|ProfilePrism||16bit/21 Entries||-||-||16bit/21 Entries||-||-|
|SilverFast Ai||16bit/33 Entries||16bit/33 Entries||-||-||-||-|
|ProfileMaker 4.1||16bit/25 Entries||16bit/25 Entries||copy of A2B0||-.||-||-|
|Epson Org||16bit/32 Entries||16bit/32 Entries||16bit/32 Entries||-||-||-|
|1)||ICC Profile Inspector gives error message for this tag|
|3)||ICC Profile Inspector gives error message|
|Monitor||Scanner||Printer||16bit Raw data||Parameters can be influenced||Profile Editor|
|EZColor||yes||yes||yes||yes||no||for Printer Profile|
|ProfileMaker 4.1||yes||yes||yes||yes||yes 5)||yes|
|1)||may work, but I did not get it to work easily|
|2)||Mainly generation algorythm|
|3)||Gamma, Contrast, Saturation, Color Bias, others|
|4)||Must be bought seperate|
|5)||Size and grey algorythm|
EZColor and WiziWYG had a little drawback with the reflection target because their profile was generated with a different target as they were evaluated afterwards. But the transmission target shows similar results at least for EZColor.
The first finding was that I was surprised that there seem to be still flaws with the compliance with the ICC standard and that the support of the profile header was quite weak. Special EZColor showed a number of problems.
I was also surprised by the wide range of results and that the freeware tool somehow showed by far the best result (at least in the deltaE) evaluation.
But in the end at least all packages gave better results than the profile supplied by Epson with the scanner.
Side remark: It is interesting that nearly all packages (beside the freeware lcms) put their company name into the copyright tag of the profile. This would mean also that the company which build the printing machine has the copyright on a book?
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