IMagick to generate GIF and skip every n image

[burt46]

Hi,

I have a IMagick PHP code that i use from a cron job to generate GIF files from folders of images. The problem is that the gifs are around 3 - 10mb in size and take too long to download.

Is it possible to generate a gif but say every n image in a folder? I have seen this is possible to extract frames from a GIF but not to generate a GIF.

I have tried various methods to reduce the GIF size and the sizes above are already optimised.

Grateful for any advice.

Many thanks
Burt

[fmw42]

You would have to write a script loop to take only every other images from the folder to make your gif. You could for example save a list of every other file into a variable or as text file and read from that text file.

The IM frame command [X-Y] does not have a skip feature, as far as I know.

It is generally a good idea to identify your IM version and platform when asking questions.

[burt46]

Thanks for the reply. I guess this is a separate feature to IM to generate the txt file? Perhaps a cron job can do this too.

Linux, IM version 6.6.3

[fmw42]

Another idea would be to delete every other image in the command sequence. In command line, suppose you have 10 images in the folder, you could do

Code: Select all

convert -delay 50  *.jpg -delete 1,3,5,7,9 -loop 0 result.gif

IM 6.6.3 is ancient (about 350 versions old). I would suggest you upgrade if you can.

[burt46]

Thanks for the feedback. I thought about this but it would delete my master images that i need for other scripts.

I cant change the IM version as it is controlled by my hosting company

[fmw42]

using -delete does not delete images from your folder, only from the in memory sequence loaded by *.jpg.

However, it would be better to load only the images you want.

Code: Select all

cd somedirectory

imgArr=(`ls`)
num=${#imgArr[*]}

list=""
for ((i=0; i<num; i=i+2)); do
list="$list ${imgArr[$i]}"
done

convert -delay 50 $list -loop 0 result.gif

[burt46]

Perfect. Many thanks for the help.

[fmw42]

If you just want JPG, then use

Code: Select all

imgArr=(`ls *.jpg`)