Search found 5 matches

by Devpool
2018-05-23T09:38:56-07:00
Forum: Users
Topic: Detecting "nearly" grayscale
Replies: 3
Views: 2172

Re: Detecting "nearly" grayscale

The S channel of HLS (or C channel of HCL) gives the saturation (or chroma), on a scale of 0.0 to 1.0. If the mean of this is low, the image is close to gray. However, an image that is totally gray except for a few high-saturation pixels will be, on average, nearly gray, so you might prefer to find...
by Devpool
2018-05-22T14:28:56-07:00
Forum: Users
Topic: Detecting "nearly" grayscale
Replies: 3
Views: 2172

Detecting "nearly" grayscale

I noticed that "convert" will automatically change the colorspace from RGB (or sRGB) to Gray with some images. AFAICT, it does this when all of the channels are identical. However, I often come across RGB images that are essentially grayscale, but the channel statistics are not *quite* identical (di...
by Devpool
2018-05-22T11:29:06-07:00
Forum: Users
Topic: Glueing images together
Replies: 2
Views: 1645

Re: Glueing images together

Assuming 40 pix: montage *.jpg -tile 2x20 NewMontage.jpg You could use a script to count the jpgs and insert the proper number in the -tile flag. ETA: this python3 script should work for you #!/usr/bin/env python3 # coding=utf-8 ## call with dir of jpg import os import sys import math import subproc...
by Devpool
2017-12-09T14:32:47-07:00
Forum: Users
Topic: Check single column of pixels
Replies: 6
Views: 3139

Re: Check single column of pixels

Is toes.png an image you test with? I tried this: magick image02.jpeg -gravity north -crop 1x+0+0 +repage -format "%[fx:standard_deviation]\n" +write info: -scale 1x1! -format "%[pixel:u.p{0,0}]\n" but I got an error: magick: MissingArgument `-format' at CLI arg 13 @ fatal/magick-cli.c/ProcessComman...
by Devpool
2017-12-07T13:41:14-07:00
Forum: Users
Topic: Check single column of pixels
Replies: 6
Views: 3139

Check single column of pixels

I'm processing a series of images similar to book scans. Most of the time they can simply be split in two, and I've set up a bash script calling convert to do just that. However, occasionally a single image runs across the entire spread. I want to flag these for manual checking. I'm thinking that I ...