JPEG2000 is slow to load in acrobat
I add and Save to a ~ 9 x 4 inch page, identical 1200 ppi images of ~ 4 x 3inches, in various formats of original image file sizes:
TIFF: 88.1 MB
PNG: 24.6 MB
JP2: 5.7 MB
The JPEG2000 gives best visual impression; is preferred choice.
When the document is opened, 'response time' is:
TIFF: essentially instant
PNG: essentially instant
JP2: approx. 4-5 seconds
The JPEG2000 format is new to me. I am impressed with result, apart from load time.
1. Is there an Acrobat setting that speaks to JP2 performance in a doc, how it loads, etc.?
2. I am aware of 'pyramids' [Quality layers?] in JP2 decoding/presentation. Perhaps an approach is to insure that the 'initial load' of the JP2 is distinctly restricted to lo-res, and image quality 'fills in' and improves to max-res during that 4-5 secs., but initial appearance is instantaneous. So far, I've been unable to address this by processing the image in QGIS [also new to me].
The slow load is unsurprising in this respect: When I view the JP2 image in Apple Preview, it's reported size is ~ 68 x 62 in. At 72 ppi. That's a lot for Acrobat to handle, when smushing it down, converting ppi, etc. I have a vague understanding that some apps display a JP2 only at a default 72 ppi. In QGIS I've set the image parameters to dimensions ~ 4 x 3 in., at 1200 ppi [exactly as the TIFF and the PNG], and Exported. However, MacOS and Preview still treat it as 72 ppi. I'd love for Acrobat to promptly load it at 72 ppi, then 'work its way up' to 1200 ppi.
Curious note: When I select the image in Acrobat, for Edit Using > Preview, the image dimensions are the expected ~ 4 x 3, AND the ppi 2400. However, Export from Preview always yields a stubborn 72 ppi.
I can upload samples, but am aiming first to better understand JP2 in Acrobat. [I'm pretty sharp with GIMP; it can't handle JP2. I've not Photoshop to work with.]
There's something fishy about taking 4 seconds to display a 5.7 MB image.
