feature request: DPI changing in batch mode
current implementation: currently it is only possible to set the DPI to the same value for all images in the batch job
field of application: e.g. fitting all images to a given size (A4, 20x30cm, etc.), for instance prior to converting them into a multi-page .pdf document, etc.
suggested solution: in file > batch conversion/rename > advanced > resize:
1) remove the technically/terminologically erroneous* checkbox use resample function (better quality)
2) add checkbox resample image. When deselected, the radio button pixels must be grayed out.
3) add drop-down list box next to or below checkbox 2), enumerating the filters from the image > resize/resample dialogue box (Lanczos, etc.) and being grayed out when checkbox 2) is deselected.
4) The set DPI value text field to value "variable", but still permit user input
If the user changes the DPI field "variable" to a specified number, then width and height should either be grayed out or changed to "variable".
To simplify the GUI, I would also suggest the whole section set new size as percentage of original and add a single radio button percentage instead.
All in all this would result in the following dialogue box (changes were only made to the bottom half of the 1st out of the 3 columns):
Note that the abovementioned changes are based on IrfanView 4.20.
* the "use resample function (better quality)" checkbox is technically erroneous, since a change in an image's pixel dimensions ALWAYS involves resampling. The distinction IrfanView draws between resizing and resampling throughout the whole program interface is simply wrong. What Irfanview refers to as "resizing" is in reality ALSO "image resampling", in particular using the "nearest neighbour" resampling algorithm (or the "bilinear" resampling algorithm).
The correct terminological use of resizing vs. resampling is explained here:
current implementation: currently it is only possible to set the DPI to the same value for all images in the batch job
field of application: e.g. fitting all images to a given size (A4, 20x30cm, etc.), for instance prior to converting them into a multi-page .pdf document, etc.
suggested solution: in file > batch conversion/rename > advanced > resize:
1) remove the technically/terminologically erroneous* checkbox use resample function (better quality)
2) add checkbox resample image. When deselected, the radio button pixels must be grayed out.
3) add drop-down list box next to or below checkbox 2), enumerating the filters from the image > resize/resample dialogue box (Lanczos, etc.) and being grayed out when checkbox 2) is deselected.
4) The set DPI value text field to value "variable", but still permit user input
((As an alternative solution, checkbox 2) can be named don't resample image (change DPI only), while drop-down list 3) and the radio button pixels would be grayed out accordingly, i.e. when checkbox 2) is selected.))
If the user changes the DPI field "variable" to a specified number, then width and height should either be grayed out or changed to "variable".
To simplify the GUI, I would also suggest the whole section set new size as percentage of original and add a single radio button percentage instead.
All in all this would result in the following dialogue box (changes were only made to the bottom half of the 1st out of the 3 columns):
Note that the abovementioned changes are based on IrfanView 4.20.
* the "use resample function (better quality)" checkbox is technically erroneous, since a change in an image's pixel dimensions ALWAYS involves resampling. The distinction IrfanView draws between resizing and resampling throughout the whole program interface is simply wrong. What Irfanview refers to as "resizing" is in reality ALSO "image resampling", in particular using the "nearest neighbour" resampling algorithm (or the "bilinear" resampling algorithm).
The correct terminological use of resizing vs. resampling is explained here:
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