Legacy ImageMagick Discussions Archive

Hi there,

Hopefully, someone can help me as I can't figure out this.
I have 78GB ~ of TIF images which need to be resampled/reduced in size to make them web friendly.

I need to keep the dimensions and in tif format. I've tried many variations of the command convert *.tif -strip -density 72 -resample 100%x100% *.tif
but can't figure this one out...

Would anyone have any ideas of how I can do it?

Cheers
J

I am not an expert in this area and will bow to any others who are. But I believe that -resample will change the resolution and the density. So try leaving off -resample and just use -density. However, you need to be sure that the input density is not already 72 dpi as that is typical. If it is, then setting the density on the output to 72 will change nothing.

Perhaps what you want to do is leave the density alone and change the resolution (image size, i.e. dimensions) using -resize to something more web compatible (< 800x600 px)

What are the dimensions and density of your input images?

There are 4000 images and the dimensions vary. The resolution also varies between 200 to 300 dpi. I am pretty sure there are no cases of 72 dpi as all are high level scanned images of reports, maps etc.

When I say web friendly, I have a web application (NOt live yet) which serves up record information from a database in multiples of ten and each image is referred to individually. The dimensions are required to be kept as they are, unfortunately. The application also provides for bulk downloading of images...

Any further advice greatly appreciated.

convert *.tif -strip -density 72 *.tif
convert: 167245.tif: unknown field with tag 33000 (0x80e8) encountered. `TIFFRea
dDirectory'.

I used the above command with one tif image (80MB) in a single folder and I get the error shown. The image after the above cmd is 480MB.

Help!

Sounds like a bad TIFF file or something in it that IM does not understand. Are you sure you have an up to data libtiff installed?