Modifying Images

labs_coordinate_pictures has many features for modifying an image:

• Open labs_coordinate_pictures.

• From the Pictures menu, choose 'Resize images...'

• Click 'Browse...', choose the directory containing the target images and click OK.

From here, you can do the following (and more):

• Left, Right to go to the previous/next image

• Page Up, Page Down, Home, End to go forwards/backwards many images

• Delete to delete the current image

• Press h to rename the current image

• Ctrl+Z and Ctrl+Y to Undo deleting, renaming, or moving a file

• Ctrl+Shift+H to replace in filename

• Press Ctrl+[ to resize / convert an image,

• Press Ctrl+Shift+K to batch resize / convert images

• If your images from a digital camera appear sideways, from the View menu, click "Auto-rotate JPGs"

• To set the EXIF rotation tag, from the Edit menu, click "Set Rotation Tag"

• To show the current image in Explorer/Nautilus, press Ctrl+W

• Press Ctrl+E or Ctrl+Shift+E to edit the current image

• Press Ctrl+Shift+X to rotate or crop the current image

Walking through each image to reduce disk space

I'll explain this with a real-world example. Let's say I've been downloading images from the internet, and I want to save disk space by resizing the images I don't care about. Labs_coordinate_pictures is a great tool for this.

• Open labs_coordinate_pictures.

• From the Pictures menu, choose 'Resize images...'

• Click 'Browse...', choose the directory containing the target images and click OK.

• When I've confirmed that an image is small enough, I'll "mark" it as "size is good", and it won't show up in the list anymore

• First, I'll press Ctrl+1 to convert .png files to lossless .webp

• Then, I'll press Ctrl+2 to mark all small files as "size is good"... files less than 50Kb are so small that it's not worth individually going through and resizing them

• Then, I'll do the following for each image:

  • If I don't want the image, press Delete to delete it

  • If the filesize of the image is appropriately small, press Shift+A to mark it as done

  • If the filesize is too large because the image is too big, press Ctrl+[ to resize the image

  • If the filesize is too large because this is a png or webp photo that would be better stored as a jpg:

    • Press Ctrl+Shift+[, which will create several jpg images at different qualities.

    • Use arrow keys to browse through the resulting images.

    • When at the the image that has the best quality at a reasonable filesize, press Ctrl+] to delete the other temporary jpgs that were created.

• When all files are marked as done, I'll see the message 'looks done'.

• Then, from the Categories menu, I'll choose Finish Categorizing, which un-marks all the files. I've now confirmed that each file is small!

Advanced

Some more ways to reduce image filesize:

• run cwebp -lossless -z 9 -m 6 -q 100 to convert a png to webp with additional strength, using more time to generate a smaller file. (labs_coordinate_pictures now uses this strength by default).

• run jpegtran -optimise -progressive -copy all to losslessly optimize jpg and keep exif data.

• run exiftool -ifd1:all= -PreviewImage= -overwrite_original to strips thumbnails from a jpg while keeping other exif metadata.