Convert to Image Resource ... Lost bytes and DPI?

[joe_l]

1. 300 DPI image (4,37 MB) placed (same colour space as document).

2. Rasterise Image.

3. Menu Layer > Convert to Image Resource. Resource Manager reports now a file size of 29,14 MB of the embedded image. Document file size is 4,92 MB.

4. Make embedded image linked. Image has now 2,31 MB and DPI was lowered to 96.

 

[Dan C]

Hi @joe_l,

Thanks for your report!

4 hours ago, joe_l said:

Image has now 2,31 MB and DPI was lowered to 96.

Can you please confirm for me, what was the DPI of your document set to? As when you rasterised the image, the DPI will have been converted to the document DPI - so I am wondering if this 96DPI change occurred earlier in the process without you realising.

Equally, was your placed image set to 100% scale in the context toolbar options before rasterising the image?

I have followed your steps here and I've been thus far unable to replicate the issues being reported. I opened a 300DPI image, in a 300DPI document and when placed set the scale options to 100% before rasterising.

Converting the layer back to an 'Image Resource' did increase the size of the embedded image, due to a change in file format. I had placed a .JPEG file, which is compressed, but when using the 'Convert to Image Resource', Publisher creates an embedded .TIFF file from the pixel layer, which is expected to be larger in size. 

Many thanks in advance for any information you can provide

[joe_l]

42 minutes ago, Dan C said:

Many thanks in advance for any information you can provide

Yes, some information was missing from my report. Sorry.

Both, document and image, have the same DPI and same ICC profile. The image is a TIFF with ZIP compression (kind of compression has no impact, already tested), placed with 100%.

Attached document and image for you to experiment.

PS: One more observation made. If the TIFF has no compression and converted back it gets a ZIP compression. But I guess this is intended.

 

testbild.afpub testbild-zip.tiff

Edited August 12, 2022 by joe_l
Added more information

[Dan C]

Many thanks for the further information and files provided!

I can confirm I've since been able to replicate this issue, though the resource manager continues to report 300DPI, the new TIFF file created & linked is incorrectly at 96DPI - therefore I have logged this as a bug with our developers now.

Thanks for your report once again