Exporting from Photolab 2. Highest "quality" Jpeg settings?


#1

I want to export my raw files as jpegs to my disk. Before Photolab 2, I got someting like 35 or 45Mb jpeg files (when choosing 100%). If I wanted “small” (or 90%), I still got around 10-15Mb files. If I choose one of the export settings (Jpeg) now in PL2…they turn up as a few hundred Kb (!).
Can someone please tell me how I can generate those higher Mb Jpeg files I got before? What settings? What parameters to change in export as…?
Thank you!


(Greg) #2

What are your export settings right now (besides the quality percentage)? Also, are you cropping your original image from full size or changing its aspect ratio?


#3

I think I just found it.
I probably should NOT activate “enable resizing” (so de-select that one). I just go for one folder containing 90% quality Jpeg settings, and one folder 100% quality. I don’t know if "Bicubic sharper"or Bicubic is then enabled or not (if not selecting “Enable resizing”). Probably not enabled? “Largest size” and “Interpolation” are greyed out anyway. “Resolution” isn’t greyed out (at 300ppi).
ICC profile “as shot”.


(Melbourne, Australia) #4

Bilinear, Bicubic & Bicubic sharper are “interpolation methods” used in the image resampling (resizing) process … If you do not “Allow image resampling” them these algorithms are not applied.

John M


#5

Thank you Greg and John! As I said, I found the answer. My fault (just a little stupid I think).


(M J D L) #6

JPEG chroma subsample setting: I don’t have my main computer w/Photolab right at hand (I think Photolab exports in 4:2:0, i.e. chroma resolution is halved compared to luma), but the ability to switch off JPEG chroma subsampling entirely (i.e. in 4:4:4 subsampling) helps exporting high quality JPEGs that can be subsequently resized and undergo the usual chroma subsampling without much visible loss of quality. Along with ensuring JPEG quantization is disabled (i.e. quality is set to 100), this allows a kind of “archival” JPEG format (of course there are losses when images are transformed into the JPEG color space anyway, so these settings don’t make the format lossless).

A simple tick mark option in the JPEG export options would suffice to change the default, e.g. “Do not subsample color”. Most JPEG graphics libraries used in programming have the option of disabling chroma subsampling, so it’s not hard to add.

Can DxO review such an enhancement? It shouldn’t be problematic to add it and have color subsampling remain on by default.