Slice image and name by row and column

[mkuhfuss]

Hi,

i need to slice an image. For example:
full.jpg = 7296x5472

1 slice = max. 1024x1024px

At the moment i use this command:

Code: Select all

convert -crop 1024x1024 full.jpg %d.jpg

With this i got imagename like:
1.jpg
2.jpg
…

But i need the name with row and column index. For example:

First row:
0_1.jpg
0_2.jpg
…
Second row:
1_1.jpg
1_2.jpg
…

My Version is: 6.9.7-4

Thanks in Advance
Markus

[snibgo]

See https://www.imagemagick.org/discourse-s ... me#p121114

[mkuhfuss]

Thansk for your answer…
This works for me:

Code: Select all

convert 7296.jpg -crop 1024x1024 -set filename:tile "%[fx:page.y/1024]_%[fx:page.x/1024]" 0_%[filename:tile].jpg

No i need to resize all Images in a loop and than slice these Thumbnails:

Example:

Original.jpg = 7296x5472px

First i need to resize this full Image to:
5472px (75%)
3648px (50%)
1824px (25%)
912px (12,5%)

Every one of these thumbnails i need to slice in 1024X1024px.

My command for resizing so far:
I realized that the following command is very slow. Is there a faster approach?

Code: Select all

convert 7296.jpg \
 \( +clone -resize 75% -write thumb_75.jpg +delete \) \
 \( +clone -resize 50% -write thumb_50.jpg +delete \) \
  \( +clone -resize 25% -write thumb_25.jpg +delete \) \
  -resize 12.5% thumb_12_5.jpg

Next my current command doesn't realy work

Code: Select all

files=(thumb_*.jpg)
total=${#files[@]}
i=0
for f in "${files[@]}"; do
	echo index $i
	convert "$f" -crop 1024x1024 -set filename:tile "%[fx:page.y/1024]_%[fx:page.x/1024]" "$i"_%[filename:tile].jpg
	i=$(( i + 1 ))
done

I want to loop the 4 files (5472px, 3648px, 1824px,912px) and i expect this result:

5472px:
0_0_1.jpg
0_0_2.jpg
...
next row:
0_1_1.jpg
0_1_2.jpg
...

3648px:
1_0_1.jpg
1_0_2.jpg
...
next row:
1_1_1.jpg
1_1_2.jpg
...


and so on...

[mkuhfuss]

Ok with this it works. But resizing is still very slow.
And it would be nice if i could do this in one command/Batch script!

Code: Select all

convert 7296.jpg \
\( +clone -resize 100% -write thumb_1.jpg +delete \) \
 \( +clone -resize 75% -write thumb_2.jpg +delete \) \
 \( +clone -resize 50% -write thumb_3.jpg +delete \) \
  \( +clone -resize 25% -write thumb_4.jpg +delete \) \
  -resize 12.5% thumb_5.jpg

Code: Select all

files=(thumb_*.jpg)
total=${#files[@]}
i=0
for f in "${files[@]}"; do
	echo index $i
	echo file $f
	convert "$f" -crop 1024x1024 -set filename:tile "%[fx:page.y/1024]_%[fx:page.x/1024]" "$i"_%[filename:tile].jpg
	i=$(( i + 1 ))
done

[snibgo]

Is there a faster approach?

Instead of "-resize", you could use "-scale" or "-sample". These are faster, and usually lower-quality for ordinary photos, but may be good enough.

Next my current command doesn't realy work

You increment "i" at every input file. But your required output filenames suggest you should increment "i" less often.

[mkuhfuss]

Oh thank you!
-sample and -scale are faster, much more faster

Quality is good enough i think too!