Resizing with batch conversion in DPP4 to a specific maximum dimension

[rmame]

I'm looking for a way to resize images during batch conversion of RAW files in DPP 4.10.50.1. What I want to do is convert the edited (and sometimes cropped) RAW files into JPEG files with a specific maximum dimension, let's say 800 pixels.

Examples:

                   original             resized

File #1 is 2000x3000  >>   533x800

File #2 is 1500x1500  >>   800x800

File #3 is 3000x2000  >>   800x533

and so on.

So you see the aspect ration of each original file (or cropped file) is maintained, but the maximum dimension of the resized file is always 800 pixels.

Is there an option that does this? I don't see one.

[jrhoffman75]

I believe if you select Lock Aspect Ratio and type 800 in both dimension boxes you will get what you want.

[rmame]

Hi John

That's what I thought, but it won't take 800 in both boxes. It seems to default to some aspect ratio, for example 1.5:1, so if you put 800 in the height box and try to put 800 in the width box, it changes that from 800x800 to 1200x800.

If every image has the same aspect ratio (e.g all landscape and all uncropped), then it's a non issue.

I'm not sure what the "default" aspect ratio is when you have dozens of (cropped) images with different aspect ratios. It might be the first one in the list or  the last one in the list I guess. It's possible if the first/last image in the list was square, then you could get it to accept 800 for both width and height. I'll have to try that, but it's a pretty clumsy way to have to do things! I'd have thought Canon would have thought of this and but in a checkbox somewhere so you could specify a maximum dimention.

[jrhoffman75]

You are correct. Sorry. I was confusing DPP with what LR does.

[Waddizzle]

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@rmame wrote:

Hi John

That's what I thought, but it won't take 800 in both boxes. It seems to default to some aspect ratio, for example 1.5:1, so if you put 800 in the height box and try to put 800 in the width box, it changes that from 800x800 to 1200x800.

If every image has the same aspect ratio (e.g all landscape and all uncropped), then it's a non issue.

I'm not sure what the "default" aspect ratio is when you have dozens of (cropped) images with different aspect ratios. It might be the first one in the list or  the last one in the list I guess. It's possible if the first/last image in the list was square, then you could get it to accept 800 for both width and height. I'll have to try that, but it's a pretty clumsy way to have to do things! I'd have thought Canon would have thought of this and but in a checkbox somewhere so you could specify a maximum dimention.

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You can define the aspect ratio of the individual files.  A batch process applies the same set of batch commands to each file.  

[Stanimal]

I'm currently using DPP 4.16 to work Raw files from an R5 mirrorless. While the software does fairly well with overall processing, the batch conversion to JPG is poorly configured. As you have noticed, there is no option to specify the long or short side dimension and have it applied to all photos in the batch process unless they are all cropped to the same orientation and ratio of width to height. Canon's "help" files/explanations are inaccurate, claiming that the long-side dimension you set is applied to the long side regardless of orientation. That might be correct if the ratio is the same, i.e. 5x4 or 4x5. It is definitely not accurate when the ratios vary between images.

 I just wasted three hours converting a batch of over 300 RAW files to JPG setting the long-side count to 2000 pixels. Again, as you've noticed, the short-side dimension then automatically sets itself to the appropriate size based on the retained ratio. As soon as that ratio changes, the 2000 pixel specification no longer applies. This is a very poor implementation of the resize tool for batch processing. Never had that problem in Light Room, not even in the standalone version 6.

[Waddizzle]

???

Lightroom works the same way.  You are limited to applying only one preset when you process multiple files.  If you want three different output sizes, then you must run three separate batch processes.

[jrhoffman75]

As I read Stanimal's post he wants all images resized to 2000 pixels on long edge, regardless of aspect ratio. 

If I am correct in my reading then LrC can do that. I use LrC to do that for club images. Max image size is 1400 wide by 1050 tall. Lightroom will resize all images so they fit within that box. 
In his case a resize setting of 2000 by 2000 would do that. 

[johnrmoyer]

For that I use graphicsmagick. It is a command line program which makes scripting easy. A for loop on the command line can do a large number of images in the background.

For example:

/opt/local/bin/gm convert IMG_7635.JPG -resize "50%"  -unsharp 0x1  -define 'jpeg:dct-method=float,jpeg:optimize-coding=true' -interlace line  -quality 97 IMG_7635cs2.JPG

where quality is from 10 to 100 as in the original JPEG specification and trades image quality against file size.

This makes a thumbnail image with a white background and I use it to make many small copies of images that each occupy the same space on a screen:

gm convert -verbose -define jpeg:size=320x240 $1.jpg +profile "*" \
 -thumbnail '160x160>' -background white -gravity center \
 -extent 160x160 thumbnails/$1.jpg

where "$1" is a variable expanded to a file name.

GraphicsMagick has a very good default resize algorithm, but one may specify other algorithms on the command line.