A little help for a newbie

Hi people!
the first topic of all: sorry for my bad english (not my native language and never had a serious class).

And the second (and most important) is: i’m very new to the imagej software and i have to measure the optical density of images like this:
Image

The habitual process is:

  1. Convert the image to 8-bit black and white
  2. Make a calibration curve with values selected under chosen at their own discretion
  3. And next measure the optical density with the yellow rectangle (yes with that little figure measure the whole image). In this case starting from the right with selection area, press M to measure and five times left arrow on the keyboard, again press M and so on until the image is finished.

A image to ilustrate

How you can imagine is a really boring and tedious task.
The question is: someone can tell me a more eficient way to make this?

Any help is really appreciated
Thanks for reading this.

Notes:
the values that i use is from the column "Mean"
the values 0%, 25%, 50% and 100% they are not exactly the ones I use
the number of measures is around 250
and i read other topics and i’m almost sure that dont’n help, if ther is one i’m sorry for repeating a topic
one more thing yes i used google translate :persevere:

Good day,

my first impression from your sample image:
You should and could improve image acquistion. (Shades and reflections must be avoided.)
Did you try to image the test tube with transmitted light? Did you try contrasting color illumination?

Just some thoughts …

Regards

Herbie

Hi, thanks for reading
I noted that problem but the only way to eliminate this problem that I could do was to take several photos from slightly different angles so the shadows and reflections can be ignored after making the analysis (compensating errors by shadows or reflections, some people made it like this before me).
And all the images are taken sadly i can’t change the photos

I like your idea of transmitted light maybe I’ll try to change the way I take these photos in the future