In my previous blog, I talked about how to use ImageMagick to square a file. Now, in this blog I’m taking it one step further.
I have a directory of photos from all over the internet, and I want to post them to a social media site. If the pictures are taller than 510 pixels, I need to square them as discussed in the last blog (and I’m adding a white padding/background). This will keep them from being cut off when I post them to the specific social media site.
Secondly, if the picture is “wide” vs “tall”, then I don’t need to add the background, but I might as well resize it to save upload/posting time. Some pictures downloaded from the internet are very large, so I’m standardizing on resizing them to a width or height of 510, whichever is smaller.
So in the Powershell, here’s what is happening:
1) Get all the files in a directory ($inputPath) and loop through them one at a time
2) Call ImageMagick “identify” to return the size of the file (primarily I need to know it’s width and height)
3) Use RegEx pattern matching to pull the width/height out of the returned string, convert them to numbers, then use compare them
4) If it is a wide picture, call the ImageMagick resize function
5) If it is a tall picture, call the ImageMagick convert function. Technically, I’m converting to a thumbnail, but it’s a very large thumbnail.
For both #4 and #5 in the above steps, the output file is a variable written to the $targetPath directory with the same filename.
cls
$inputPath = "e:\Photos\ToResize\"
$targetPath = "e:\Photos\Resized\"
$files = get-ChildItem $inputPath
foreach ($file in $files)
{
#$output = & magick identify e:\Photos\ToResize2cca60-a2a9-49b8-964e-b228acf517f3.jpg
# shell out to run the ImageMagick "identify" command
$output = & magick identify $file.FullName
$outFilename = $targetPath + $file.Name
# sample value of $output:
#e:\Photos\ToResize2cca60-a2a9-49b8-964e-b228acf517f3.jpg JPEG 768x512 768x512+0+0 8-bit sRGB 111420B 0.000u 0:00.000
write-host $output
$pattern = ".* (\d*?)x(\d*?) .*"
#the first parenthese is for capturing the cityState into the $Matches array
#the second parentheses are needed above to look for $ (which is end of line)
#or zip code following the city/state
$isMatch = $output -match $pattern
if ($Matches.Count -gt 0)
{
#$width = $Matches[1];
#$height = $Matches[2];
[int]$width = [convert]::ToInt32($Matches[1]);
[int]$height = [convert]::ToInt32($Matches[2]);
if ($height -gt $width)
{
$orientation = "tall";
# shell out to run the ImageMagick "convert" command
& convert -define jpeg:size=510x510 $file.FullName -thumbnail "510x510>" -background white -gravity center -extent "510x510" $outFilename
}
else
{
$orientation = "wide";
# shell out to run the ImageMagick "convert" command
& convert -resize 510x510^ $file.FullName $outFilename
}
Write-Host ("file=$($file.name) width=$width height=$height orientation=$orientation `n`n");
}
else
{
Write-Host ("No matches");
}
}
Filed under: Graphics