ExifTool looks like a very promising tool to fiddle with all sorts of JPEG metadata (needed for smush.it) but first I had to make sure I can install it on Dreamhost. Although installation didn't go as described on the exiftool site (since I don't have sudo access on Dreamhost), it's still installable and it's actually pretty easy.
- ssh to your DH box and go to the directory that will contain the tool, in my case it's my home directory
- Download the latest version of the code, e.g.
wget http://www.sno.phy.queensu.ca/~phil/exiftool/Image-ExifTool-7.59.tar.gz
- Uncompress the code archive
tar -xf Image-ExifTool-7.59.tar.gz
- Delete the original archive
rm Image-ExifTool-7.59.tar.gz
- Rename the newly created
Image-ExifTool-7.59
to something shorter to type, e.g. "et"
mv Image-ExifTool-7.59 et
- All done! You can now run it from any directory and show help info like
~/et/exiftool - h
You can also test the new installation with some of the images found in the exiftool test directory, like so:
$ ~/et/exiftool ~/et/t/images/IPTC-XMP.jpg ExifTool Version Number : 7.59 File Name : IPTC-XMP.jpg File Size : 20 kB File Modification Date/Time : 2005:12:31 13:05:50-08:00 File Type : JPEG MIME Type : image/jpeg JFIF Version : 1.02 Exif Byte Order : Little-endian (Intel, II) Image Description : A witty caption Make : FUJIFILM Camera Model Name : FinePix2400Zoom Orientation : Horizontal (normal) X Resolution : 72 Y Resolution : 72 Resolution Unit : inches Software : Adobe Photoshop 7.0 Modify Date : 2004:02:26 09:36:46 Artist : Phil Harvey Y Cb Cr Positioning : Co-sited Copyright : Copyright 2004 Phil Harvey F Number : 3.5 Exposure Program : Program AE ISO : 100 Exif Version : 0210 Date/Time Original : 2001:05:19 18:36:41 Create Date : 2001:05:19 18:36:41 Components Configuration : YCbCr Compressed Bits Per Pixel : 1.6 ... ... [snip] ... Encoding Process : Baseline DCT, Huffman coding Bits Per Sample : 8 Color Components : 3 Y Cb Cr Sub Sampling : YCbCr4:4:4 (1 1) Aperture : 3.5 Image Size : 100x80 Shutter Speed : 1/64 Focal Length : 6.0 mm Light Value : 9.6