no bug Resize based on DPI in batch mode doesn't work as expected

[drphilosopher]

Hi,

I'm using Irfanview 64-bit version 4.62.

If I select Batch Conversion/Rename -> Advanced -> Resize based only on old/new value, resize doesn't work as expected.

If the original images are 600 DPI and I select 500 DPI for the new value, the images are resized by the expected amount. However, if I select 510 DPI, the images are still resized by the same amount. Changing the target DPI from 500 to 510 has no effect.

The reason this result is unexpected is because, if I resize a single image by changing the DPI, the amount of resizing is very sensitive to the exact selection of DPI. Using the same numbers as in the batch case, the single image case produces two different results that correspond very precisely to 500 DPI and 510 DPI.

I'm not sure if there is a reason behind this limitation, but it would be nice if the DPI could be set more precisely in the batch case.

Thanks.

Darrell

[Bhikkhu Pesala]

In my test on 4.62 32-bit the resizing was precise.
510/500 = 1.02
1912 pixels / 1875 pixels = 1.0197333

The results with the 64-bit version were the same, as one would expect.

[drphilosopher]

I was able to get it to work.

When I first tried to do the resize, I didn't know there was an option to resize based on DPI, so I calculated the resize factor myself and entered it as a percentage (83%) by checking, "Set new size as percentage of the original:" and filling in the boxes. When I saw the option to "Resize based only on the new/old DPI value", I checked that option which grayed out the Width and Height percentages. However, the "Set new size as percentage of the original" box was still checked and was overriding the DPI option. I found that I could override that behavior by either checking the "Set new size" box or unsetting and resetting the "RESIZE" box, which has the same effect. I don't know what would happen if there were values in the "Width" and "Height" boxes.

Once the "Width%" and "Height%" boxes were grayed out, there was no way to erase the values in those boxes and there was no way to directly unselect the "Set new size as percentage of the original" box. The values and selections survive restarting the program. However, as I said above, I was able to unselect that box by selecting a different one. Perhaps it should be unselected by selecting the resize by DPI option.



Anyway, I was able to get it to work.

Thank you for your help.

Darrell