Printer Profile Validation: M1 vs. M2 and ΔE2000 Evaluation

[jctay]

Just some out-of-the-box thinking: would it be possible to create a compatible chart in i1Profiler using a patch set generated by ChromIQ?

The idea is to let ChromIQ handle the entire workflow, from generating the chart to preparing it for printing. The printed chart can then be measured using i1Profiler, with the measurement data sent back to ChromIQ for further processing.

The "conversion" process requires no interaction with ChromIQ.

 

[itsab1989]

It already is. In the export folder for every run you find the files to load into i1Profiler.

 

[pharmacist]

Unfortunately the export from ti1 to to pwxf is not so succesfull, as the ti2 determines which patch is on which strip and which row and not the ti1, thus I have tried the conversion and all the patches are translated 90 degrees and I have to make a virtual page of 297x240 mm to encompass the whole chart on a single page:

You can see the whole ChromIQ layout is turned 90 degrees thus the ChromIQ generated target cannot be scanned with i1Profiler.

When I set the page in i1Profiler to A4 and 8x8 mm I get this:

So totally out of sync.. The problem is that the patch width setting in i1Profiler determines the amount of patches per strip (which is logical, because of the limited headway of the scanning jig moving from left to right):

When choosing single scan (i1Pro1) with space bars in i1Profiler the minimum patch height 9.0. However in practive 7.5 mm with some care can be done perfectly with the i1Pro1 scanning jig (myself and @Alan G both have done this) and with with a patch width of 7.3 mm (use legacy charts), you can put 27 patches on a row:

When you uncheck "use legacy charts" (dual scan) you can 33 patches on a row:

For A4 (dual scan: 8 mm patch height):

7-7.3 mm gives 33 patches giving a matrix of 20 rows x 33 patches (total: 660) on paper size: 297x210 mm (A4)
7.4-7.8 mm gives 31 patches giving a matrix of 21 rows x 31 patches (total: 651) on paper size 297x210 mm (A4)
7.9-8 mm gives 30 patches giving a matrix of 22 rows of 30 patches (total: 660) on paper size: 297x215 mm
8.1-8.3 mm gives 29 patches giving a matrix of 23 rows of 29 patches (total: 667) on paper size: 297x220 mm
8.4-8,9 mm gives 27 patches giving a matrix of 24 rows of 27 patches (total: 648) on paper size: 297x230 mm
9-9.3 mm gives 26 patches giving a matrix of 25 rows of 26 patches (total: 650) on paper size: 297x240 mm

For A4 (single scan: 9 mm patch height for the older i1Pro1 and for i1Pro2 in single scan mode):

7.3-7.4 mm gives 27 patches giving a matrix of 24 rows of 27 patches (total: 648) on paper size: 297x240 mm:

(from 7,5 mm and more the amount of rows increases above the threshold of maximum 24 rows, making the stripes to be too small for the scanning eye for the i1Pro1 to be ergonomically scanned).

The above data can be used by Claude to determine the exact configuration and settings when converting from ti2 to pwxf-format.

When you choose legacy chart in i1Profiler (single scan method) the patch height increases from 8 to 9 mm, thus Claude must take this into account when calculating the exact configuration of the patch layout of the pwxf file when converting from the ti2-file.

 

[jctay]

Unfortunately the export from ti1 to to pwxf is not so succesfull, as the ti2 determines which patch is on which strip and which row and not the ti1, thus I have tried the conversion and all the patches are translated 90 degrees and I have to make a virtual page of 297x240 mm to encompass the whole chart on a single page:

View attachment 19607

You can see the whole ChromIQ layout is turned 90 degrees thus the ChromIQ generated target cannot be scanned with i1Profiler.

When I set the page in i1Profiler to A4 and 8x8 mm I get this:

View attachment 19608

So totally out of sync.. The problem is that the patch width setting in i1Profiler determines the amount of patches per strip (which is logical, because of the limited headway of the scanning jig moving from left to right):

When choosing single scan (i1Pro1) with space bars in i1Profiler the minimum patch height 9.0. However in practive 7.5 mm with some care can be done perfectly with the i1Pro1 scanning jig (myself and @Alan G both have done this) and with with a patch width of 7.3 mm (use legacy charts), you can put 27 patches on a row:

View attachment 19609

When you uncheck "use legacy charts" (dual scan) you can 33 patches on a row:

View attachment 19610

For A4 (dual scan: 8 mm patch height):

7-7.3 mm gives 33 patches giving a matrix of 20 rows x 33 patches (total: 660) on paper size: 297x210 mm (A4)
7.4-7.8 mm gives 31 patches giving a matrix of 21 rows x 31 patches (total: 651) on paper size 297x210 mm (A4)
7.9-8 mm gives 30 patches giving a matrix of 22 rows of 30 patches (total: 660) on paper size: 297x215 mm
8.1-8.3 mm gives 29 patches giving a matrix of 23 rows of 29 patches (total: 667) on paper size: 297x220 mm
8.4-8,9 mm gives 27 patches giving a matrix of 24 rows of 27 patches (total: 648) on paper size: 297x230 mm
9-9.3 mm gives 26 patches giving a matrix of 25 rows of 26 patches (total: 650) on paper size: 297x240 mm

For A4 (single scan: 9 mm patch height for the older i1Pro1 and for i1Pro2 in single scan mode):

7.3-7.4 mm gives 27 patches giving a matrix of 24 rows of 27 patches (total: 648) on paper size: 297x240 mm:

View attachment 19611

(from 7,5 mm and more the amount of rows increases above the threshold of maximum 24 rows, making the stripes to be too small for the scanning eye for the i1Pro1 to be ergonomically scanned).

The above data can be used by Claude to determine the exact configuration and settings when converting from ti2 to pwxf-format.

When you choose legacy chart in i1Profiler (single scan method) the patch height increases from 8 to 9 mm, thus Claude must take this into account when calculating the exact configuration of the patch layout of the pwxf file when converting from the ti2-file.

Nice attempt!

Example: 15 Patches

1. ChromIQ Format

Arrange the 15 patches in a 5 × 3 matrix across 3 pages.
Following ChromIQ's convention, the chart consists of 3 strips: Strip A, Strip B, and Strip C.
Scanning direction: Column-wise.

2. i1Profiler Format

Rearrange the same 15 patches into a 3 × 5 matrix across 3 pages.
Following i1Profiler's convention, the chart consists of 3 rows: Row 1, Row 2, and Row 3.
Scanning direction: Row-wise.

Next: 192-Patch Conversion Test

 

[jctay]

The converter seems to work fine with small samples, but not with the 192-patch chart.

 

[jctay]

The problem is that Patchtool does not allow users to specify the number of columns.

As a result, the converted layout appears as follows when viewed in Patchtool:
Rows 1 and 2 are merged into the same row.
Rows 3 and 4 are merged into the same row.
And so on.

Patches from ChromIQ

Converted to i1Profiler Layout

 

[pharmacist]

I see you are using my miniature 192 patch target I made for i1Profiler

 

[jctay]

I see you are using my miniature 192 patch target I made for i1Profiler

Yes Sir

Excellent work on your 576-patch chart! More importantly, it delivers good neutrality in real-world testing.


There has been little progress on the compatible chart, so I'll put that work on hold for now.

 

[itsab1989]

I have asked Claude to try and implement your requested feature as an experimental feature and make a step by step guide how it is supposed to work:

@jctay @pharmacist, this is for you: one sheet printed by ChromIQ that you can also measure in i1Profiler, and bring back into ChromIQ.

Before you start, please keep in mind:

• It is a beta option, off unless you switch it on.
• It works only for the i1Pro 2 and the i1Pro 3, read by hand along the ruler, and only for charts without spacers. Not for the original i1Pro, the i1Pro 3 Plus, the i1iO, the i1iSis or any other instrument.
• The layout was checked patch for patch in i1Profiler 3.8.8 itself: for the chart in this guide, i1Profiler's chart and the turned ChromIQ page have all 504 of 504 patches in the same place. But nobody has measured a real sheet yet, because I have no i1Pro 2 or i1Pro 3.
• The import pictures at the end use a test file, not a real measurement.

1. Update to ChromIQ 4.3.17

Download it here: https://github.com/itsab1989/ChromIQ/releases/tag/v4.3.17

2. Switch the option on

Open Preferences (the Preferences button at the top right, or ⌘, on a Mac and Ctrl+, on Windows), go to the Beta tab and tick "Also write an i1Profiler chart that matches the printed ChromIQ sheet (i1Pro 2 and i1Pro 3, beta)". Press OK.

The ⓘ button next to it explains everything in detail:

3. Which charts qualify

ChromIQ writes the i1Profiler files only for a chart that i1Profiler can lay out exactly like the printed sheet:

• an RGB chart made with "Use the ChromIQ layout engine instead of printtarg", for the instrument i1Pro / i1Pro 2 / i1Pro 3;
• Spacers: None, and every strip full;
• a patch length that gives i1Profiler exactly as many patches on one row as the strip holds. i1Profiler puts as many patches on a row as fit into about 241.5 mm. With 24 patches per strip the patches must be longer than 9.70 mm and at most 10.06 mm; with 30 per strip, longer than 7.82 mm and at most 8.05 mm.
• For the i1Pro 2 the patches must also be at least 10 mm long, as X-Rite asks. So 10 mm patches with 24 per strip work for both instruments.

If a chart does not qualify, ChromIQ only writes the note, which says why, with the real numbers, plus one line in the Create Chart log.

4. Make the chart

On 1. Create Chart, choose MANUAL. This is the chart I used, and it qualifies for both the i1Pro 2 and the i1Pro 3:

• Instrument: i1Pro / i1Pro 2 / i1Pro 3
• Paper: A4 (210 × 297 mm) Portrait, Pages: 1
• Create layout: Prioritise patch size, then fit to page
• Patch size (mm): 8 × 10 (8 mm across the strip, 10 mm along it)
• the patch count left on Auto, so the page is filled with full strips

Then open Expert Options and set Spacers: None:

Press GENERATE CHART. You get one A4 sheet with 504 patches: 21 strips of 24 patches, 8.04 × 9.99 mm on screen, no spacers, and the margin check says Margins: OK.

5. Where the files are

The Create Chart log shows the new files being written:

They are in the run's exports folder (for example ~/ChromIQ/<project name>/runs/run1/exports/):

• <name>-i1profiler-turned-i1Pro2.txf: the i1Profiler test chart for the i1Pro 2
• <name>-i1profiler-turned-i1Pro3.txf: the same for the i1Pro 3
• <name>-i1profiler-turned.json: the order file ChromIQ needs to bring the measurement back. Please do not edit or move it.
• <name>-i1profiler-turned-how-to.txt: a note with every step for exactly this chart, including the grid i1Profiler must show

The File Guide lists them too (the ? button at the top right, then Where are my files? (folder guide)):

6. Print from ChromIQ as usual

Print the chart on 2. Print Chart, exactly as you always do. Do not print i1Profiler's chart: the whole point is to measure ChromIQ's sheet.

7. Turn the sheet

Turn the printed sheet a quarter turn anticlockwise: the strip labels are now on the left, and strip A is the bottom row. Every ChromIQ strip is now one i1Profiler row, read from left to right.

8. Load the .txf in i1Profiler

On i1Profiler's start page, set User Mode to Advanced, and under Application Settings set Default display device to the family of the instrument you measure with (the i1Pro 2 family for an i1Pro 2, the i1Pro 3 family for an i1Pro 3). This matters: with the other family, i1Profiler reads the patch size on the wrong scale and the rows come out wrong. Then choose Printer, Profiling.

Press Next on the Patch Set page. On the Test Chart page, under Page Data, press Load and choose the .txf for your instrument. When i1Profiler asks "Would you like to copy this file to the assets folder?", either answer is fine.

9. Check the grid

i1Profiler must now show exactly the grid the note names. For this chart: 24 columns, 21 rows, 1 page (Page 1 of 1), patch width 10 mm. If it shows anything else, stop: the rows would not match the sheet.

(i1Profiler names its patches by its own columns and rows, A to X and 1 to 21. Its "A1" is not ChromIQ's A1. That is expected.)

10. Measure

Press Next to the Measurement page and choose a measurement mode:

• i1Pro 2: Single Scan (M0), or Dual scan (M0,M1,M2 and OBC) if you want M1 and M2 as well (each row is then read twice, forwards and back);
• i1Pro 3: Single scan (M0,M1,M2 and OBC), which gives M0, M1 and M2 in one pass.

Calibrate, and measure the rows from top to bottom, each one from left to right, starting and ending on the white paper beside the row. i1Profiler checks every row against the colours it expects and asks you to read it again if it does not fit. Please always do that: it is the check that catches a row read in the wrong place, and ChromIQ cannot see a misplaced row afterwards. Leave i1Profiler's Scramble patches setting off, and measure the whole chart.

11. Save the measurement

When every row is measured, press Save under Page Data on the Measurement page and save it as an .mxf file (the format this was checked with). A CGATS text export that includes the RGB values works the same way. One without device values is refused for this chart, because only the RGB values tell ChromIQ which patch each reading belongs to.

12. Import in ChromIQ

Open the run, go to 3. Measure, press IMPORT, choose the file with the folder button beside Measurement File (from i1Profiler), and press IMPORT MEASUREMENT. ChromIQ checks that the device values in the file are this chart's, entry for entry, and then puts every reading on its own patch. A file that does not match, or holds only part of the rows, is refused and nothing is changed. If the file holds more than one measurement condition, ChromIQ uses M2, then M1, then M0.

The next three pictures use a test file, not a real measurement: it was generated from this chart's .txf the way ChromIQ's own tests build one.

The log line to look for is "This is a measurement of the turned i1Profiler chart, so ChromIQ put every reading on its own patch ... in the turned order":

After that you can build the profile on 4. Build Profile as usual.

Please tell me how it goes

This is the part we could not test: a real sheet, a real i1Pro 2 or i1Pro 3, and a real i1Profiler export. If one of you tries it, I would love to hear whether every row reads in i1Profiler, whether the import goes through, and anything that was unclear. Feedback is very welcome, good or bad.

 

[itsab1989]

Looking at the instructions I see some shortcomings already (like it should be rotated 180° I guess) but I trust you guys to try it and give feedback.