High Pass filter for a batch?

[philipmorg]

I have a sequence of Photoshop actions that produces an effect that I like very much. I only have Photoshop Elements, so I'm not aware of a way to automate this within Photoshop. I'd like to create the same effect using one or more ImageMagick commands (preferably using a script that can process a whole folder of images). Can anyone help?

Here are the Photoshop actions:

• Create duplicate layer
  Run the High Pass filter on this layer using a radius of 60 pixels
  Set the layer to Hard Light, 40% opacity
  Create a second duplicate layer
  Run the High Pass filter on this layer using a radius of 3 pixels
  Set the layer to Overlay, 50% opacity
  Flatten the image

[snibgo]

"High pass filter" is probably another version of "sharpen".

[fmw42]

post links to an input and output example so we can see if it can be closely duplicated

it is hard to tell without testing, but the PS high pass filter, from appearances, could be just a laplacian or LoG or the image minus a gaussian low pass filter.

[fmw42]

I have determined from some testing that the PS high pass is equivalent to the image minus an IM -blur radiusxsigma with radius=0 and sigma=photoshop radius at 50% bias (in non-HDRI)

Here is a test image:


Here is the photoshop high pass result at radius=60


Here is my IM high pass processing command and result:

infile="birdofparadise.jpg"
blur=60
convert $infile \
\( -clone 0 -blur 0x60 \) \
\( -clone 0 -clone 1 +swap -compose mathematics \
-set option:compose:args "0,1,-1,0.5" -composite \) \
-delete 0,1 birdofparadise_im_hp${blur}.jpg



Here is the photoshop high pass result at radius=3


Here is my IM high pass processing command and result:

infile="birdofparadise.jpg"
blur=3
convert $infile \
\( -clone 0 -blur 0x60 \) \
\( -clone 0 -clone 1 +swap -compose mathematics \
-set option:compose:args "0,1,-1,0.5" -composite \) \
-delete 0,1 birdofparadise_im_hp${blur}.jpg




Here is doing all the processing requested.


infile="birdofparadise.jpg"
outfile="birdofparadise_processed.jpg"
convert $infile \
\( -clone 0 -blur 0x60 \) \
\( -clone 0 -clone 1 +swap -compose mathematics \
-set option:compose:args "0,1,-1,0.5" -composite \
-matte -channel A -evaluate set 40% +channel \) \
\( -clone 0 -blur 0x3 \) \
\( -clone 0 -clone 3 +swap -compose mathematics \
-set option:compose:args "0,1,-1,0.5" -composite \
-matte -channel A -evaluate set 50% +channel \) \
\( -clone 0 -clone 2 -compose hardlight -composite \
-clone 4 -compose overlay -composite \) \
-delete 0-4 $outfile



A before and after example from the requestor would be nice to see and test the kind of imagery that is important to him.

[philipmorg]

Thanks for the attempts to help!

You can see an example of the effects of this sequence of actions here: http://philipmorgan.net/HPFilterExamples

[philipmorg]

Wow! That was exactly what I'm looking for FMW42! Thank you so much for putting that together. I tried it on my sample file (you can see the comparison to the Photoshop filtered version here: http://philipmorgan.net/HPFilterExamples) and it produced a result, that to my eye, is identical!

I'll try to research this on my own, but if you know an easy way for the script to process multiple files (like all the .jpg files in a given folder) and could share that, I'd be very appreciative. I'm using Ubuntu linux, BTW.

Thanks,
--Philip.

[fmw42]

One would have to script that in a loop over the files in a directory. I will see what I can do with that for you. Do you need to process only jpg or any image? Do you have files with spaces in the name? Do you want to overwrite the images in the directory (not a good idea) or change the name and write them to the same directory or write them to another empty directory with the same name or with a modified name?


I also want to convert this into a script for a given image so that one can easily vary the parameters.

[anthony]

I have determined from some testing that the PS high pass is equivalent to the image minus an IM -blur radiusxsigma with radius=0 and sigma=photoshop radius at 50% bias (in non-HDRI)

Here is my IM high pass processing command and result:

Code: Select all

infile="birdofparadise.jpg"
blur=60
convert $infile \
\( -clone 0 -blur 0x60 \) \
\( -clone 0 -clone 1 +swap -compose mathematics \
-set option:compose:args "0,1,-1,0.5" -composite \) \
-delete 0,1 birdofparadise_im_hp${blur}.jpg

Hmmm sounds like a job for the new morphology convolutions

Code: Select all

convert birdofparadise.jpg -set option:convolve:scale -100,100% -bias 50% \
           -morphology convolve Gaussian:0x3  birdofparadise_morph.jpg

And that can be used with mogrify as it does not require the handling multiple images to produce a result.

[philipmorg]

I would like to be able to process a folder of either TIF or JPG images. I would ordinarily not have spaces in the file name. I think I'd want the processed files to end up in a subdirectory of the original directory (something like ./processed) with the original name + "edited."

Thanks,
--Philip.

One would have to script that in a loop over the files in a directory. I will see what I can do with that for you. Do you need to process only jpg or any image? Do you have files with spaces in the name? Do you want to overwrite the images in the directory (not a good idea) or change the name and write them to the same directory or write them to another empty directory with the same name or with a modified name?


I also want to convert this into a script for a given image so that one can easily vary the parameters.

[fmw42]

I have made the processing into a script called enrich on my web site below. It processes only one image at a time as do all my other scripts.

I will post some code here as soon as I can to loop over a directory as requested above.

[fmw42]

convert birdofparadise.jpg -set option:convolve:scale -100,100% -bias 50% \
-morphology convolve Gaussian:0x3 birdofparadise_morph.jpg

But gaussian is much slower than -blur, especially when he needs sigma=60. So you really need to combine in sequence two morphology convolve blur:0x3 with its 90 degree rotated version. That would be something like

convert birdofparadise.jpg -set option:convolve:scale -100,100% -bias 50% \
-morphology convolve blur:0xsigma,0 -morphology convolve blur:0xsigma,90 birdofparadise_morph.jpg

But it does not duplicate my results or that of Photoshop for sigma=60 and has some severe artifacts. I suspect I am not doing the scaling and bias properly. Anthony, can you correct this?

He also needs two different sizes blurs and two composites, so not really suitable for mogrify. Correct me if I am wrong.

[fmw42]

Philip,

I have made a script to loop over a directory of images. You can get it at http://www.fmwconcepts.com/misc_tests/hpbatch

It may download as hpbatch or hpbatch.sh

You can remove the .sh and run it as --- bash fullpathto/hpbatch

or leave the .sh and run it as --- bash fullpathto/hpbatch.sh

Either way, you need to edit a couple of parameters at the top --- provide your actual full path to your image directory and provide your actual full path to IM convert.

It will create a subdirectory (processed) in your image directory if it does not already exist. It will also replace spaces in filenames with underscores in the output directory. It will process files that have suffixes of jpg, tif or tiff (or with all caps) only.

Let me know if you have any problems. If it does not run, be sure it has executable permissions (chmod u+x hpbatch).

Fred

[anthony]

Thinking about this problem last night a scaling/unity addition of -100,100% is actually equivelent to a DoG (Difference of Gaussians) where the positive gaussian has a sigma of '0'
That is unity - gaussian

As such...

Code: Select all

convert birdofparadise.jpg -set option:convolve:scale -100,100% -bias 50% \
           -morphology convolve Gaussian:0x3  birdofparadise_morph.jpg

is equivelent to

Code: Select all

convert birdofparadise.jpg  -bias 50% \
           -morphology convolve DoG:0x0,3  birdofparadise_dog.jpg

Note the order of the two sigma arguments. '0' is unity, '3' is the subtracted gaussian.

Of course as Fred points out...

But gaussian is much slower than -blur, especially when he needs sigma=60.

At large sigmas any form of 2-dimensional gaussian convolution is orders of magnitude slower than using 2, 1-dimentional Blurs (whcih the -blur operator provides).
See Gaussian vs Blur Kernels

So you really need to combine in sequence two morphology convolve blur:0x3 with its 90 degree rotated version. That would be something like

Code: Select all

convert birdofparadise.jpg -set option:convolve:scale -100,100% -bias 50% \
           -morphology convolve blur:0xsigma,0 -morphology convolve blur:0xsigma,90  birdofparadise_morph.jpg

But it does not duplicate my results or that of Photoshop for sigma=60 and has some severe artifacts. I suspect I am not doing the scaling and bias properly. Anthony, can you correct this?

First

Code: Select all

-morphology convolve blur:0xsigma,0 -morphology convolve blur:0xsigma,90

using advanced multi-kernel features of morphology is equivalent to

Code: Select all

-morphology convolve blur:0xsigma\>

Second BOTH the bias and the unity (original image) will be added to twice!!!! The result is as you found a usless image!

However I have had some minor success with using a 50% unity addition.

Code: Select all

   convert birdofparadise.jpg -set option:convolve:scale -100,50% -bias 50% \
              -morphology convolve blur:0xsigma\>    birdofparadise_blur_trial.jpg 

The real problem is that a DoG kernel (what you are really doing) is NOT separatable. You can not use a 2-pass 'Difference of Blurs' to generate a DoG (I tried). The one example I generated of doing a DoG using blurs is shown as the last example of the introduction of the DoG kernel as is basically what you were doing initially using multiple images.

The only other solutions I can think of (using multi-kernel minus composition) would require HDRI versions of IM to prevent clipping of values between images, and even then Dog Separability problem remains a problem

He also needs two different sizes blurs and two composites, so not really suitable for mogrify. Correct me if I am wrong.

You are not wrong. As soon as multiple image processing becomes involved, "mogrify" is no longer really suitable.

[philipmorg]

Thanks Fred! It works perfectly.

-P

Philip,

I have made a script to loop over a directory of images. You can get it at http://www.fmwconcepts.com/misc_tests/hpbatch

It may download as hpbatch or hpbatch.sh

You can remove the .sh and run it as --- bash fullpathto/hpbatch

or leave the .sh and run it as --- bash fullpathto/hpbatch.sh

Either way, you need to edit a couple of parameters at the top --- provide your actual full path to your image directory and provide your actual full path to IM convert.

It will create a subdirectory (processed) in your image directory if it does not already exist. It will also replace spaces in filenames with underscores in the output directory. It will process files that have suffixes of jpg, tif or tiff (or with all caps) only.

Let me know if you have any problems. If it does not run, be sure it has executable permissions (chmod u+x hpbatch).

Fred

[fmw42]

Happy to help and that it worked OK.