Legacy ImageMagick Discussions Archive

@fmw42,

As I already explained, I had the white and black values mixed up the wrong way around.
In my mind I thought that WHITE was #000, and BLACK was #FFF

I was referring to absolute white and black, but nevermind it seems that I have mixed the two up.

Black being #000, white being #FFF

Are you sure you do not want to make all pixels above a certain graylevel into white to even out all the (near-) white areas.

But isn't white 0, and black 255?

Anyhow, your suggestion of this works:

magick image -white-threshold XX% result


If this is not what you want, then please post an ...

Hi,

I'm trying to make all white pixels below a certain threshold white.
I scanned some pages from a book and there are some not-quite-white pixels, that I want to make true white.

I can do this in another image app by using the wand tool with a 20% threshold, then cutting everything and pasting ...

Thanks fmw42, that worked.
I added the trimming at the bottom however, just to make sure that there were no extraneous not-quite-white pixels.
Cheers.

Thanks GeeMack too.

Have a good Easter guys, whether you celebrate it or not!

GeeMack has the right idea.

I want to trim the top, pad 28px at the top, then pad the remaining image to 1024px height.

Now I'm looking to so something similar, but horizontally instead.

I don't want to center the cropped images horizontally, because all the pages are different lengths
So I want to add a 28px border to the top instead
Then I want to pad the remainder of the image at the bottom to make it 1024px ...

Ok, now I've got it.

magick *.png -set filename:f "%[t]" ^
-set option:dimensions "%wx%h" ^
-background black -fuzz 25% ^
-gravity east -splice 1x0 ^
-trim +repage -gravity east -chop 1x0 ^
-gravity west -splice 1x0 ^
-trim +repage -gravity west -chop 1x0 ^
-background white -gravity center ...

You use "filename:f" but you haven't set it anywhere.

I tried setting it in the beginning, but then it throws me another error for option:dimensions

magick *.png -set filename:f ^
-set option:dimensions "%wx%h" ^
-background black -fuzz 25% ^
-gravity east -splice 1x0 ^
-trim +repage -gravity ...

I can't get it to output multiple files for some reason.
Can someone please take a look at my syntax and tell me what I'm doing wrong?

magick *.png ^
-set option:dimensions "%wx%h" ^
-background black -fuzz 25% ^
-gravity east -splice 1x0 ^
-trim +repage -gravity east -chop 1x0 ^
-gravity west ...

Yeah, that works.

Is there a way to pad it evenly on both sides to the original page width?
Because I can't have an arbitrary amount of padding in case the images are different sizes.

Perfect, thanks.
That's EXACTLY what I was looking for.

Hi fmw42 ,

The images are in PNG format.
There is no virtual canvas offset. It's just a matter of some sloppy (lazy) scanning. :oops:

I'm not too worried about dark spots, it doesn't need to be perfect. It's just the more dramatic shifts that I find off-putting.

Here's an example:
http://i1219 ...

Hi,

Is there anyway to vertically crop an image (of text) to the leftmost and rightmost colored (non-white) pixels?

The reason I'm asking is because I scanned an old out-of-print book to make an e-book, and the page margin keeps jumping between pages, and it's bothering me. Sometimes the text ...