PainShop Pro 9

Author

script

gwen

2007-05-27, 6:18 pm

I have 658 pictures that were initially edited using an improperly
calibrated CRT monitor. A new, properly calibrated LCD monitor, now
reveals that all the photos have an excess brightness of about 14 units
under Adjust/Brightness and Contrast.

Would someone please provide me with a script that would reduce the
brightness of each photo in a folder that contained these photos?

If that's possible?

thank you, gwen

Fred Hiltz

2007-05-27, 6:18 pm

gwen wrote:
> I have 658 pictures that were initially edited using an
> improperly calibrated CRT monitor. A new, properly calibrated
> LCD monitor, now reveals that all the photos have an excess
> brightness of about 14 units under Adjust/Brightness and
> Contrast.
>
> Would someone please provide me with a script that would
> reduce the brightness of each photo in a folder that contained
> these photos?
>
> If that's possible?

It is indeed possible, but such an easy Do It Yourself project that
you might like to learn a bit more about PSP 9 with it.

Open one of those images. Start recording a script. Make the
brightness adjustment. Save the script. Close the image.

Now File > Batch Process. Select the images to alter. Tell it to use
the script you recorded. Tell it where to write the altered images
and what format to use. Click Start.

Hints: Make a copy of the original images elsewhere, just in case
the results are not what you want. Read more about recording scripts
and using them in a batch process under Help > Contents > Automating
Tasks.
--
Fred Hiltz, fhiltz at yahoo dot com

Spandex Rutabaga

2007-05-27, 6:18 pm

Fred Hiltz wrote:
>
> gwen wrote:
>
> It is indeed possible, but such an easy Do It Yourself project that
> you might like to learn a bit more about PSP 9 with it.

Everything Fred says is good. However, you should be aware of
some limitations. All the original image values that were
pushed beyond the limit of 255 units by the original brightness
adjustment were set to the maximum of 255. Consequently all color
differences among such pixels were lost. Darkening these pixels
will simply make them darker but won't bring back image
information that was destroyed by the original adjustment. In
future it might be wiser to use Gamma Adjustment (rather than
Brightness/Contrast) to adjust the overall lightness of the
image or to use a more sophisticated filter with more control
such as Levels or Histogram Adjustment (both of which also
include gamma adjustment among other possibilities).

> Open one of those images. Start recording a script. Make the
> brightness adjustment. Save the script. Close the image.
>
> Now File > Batch Process. Select the images to alter. Tell it to use
> the script you recorded. Tell it where to write the altered images
> and what format to use. Click Start.
>
> Hints: Make a copy of the original images elsewhere, just in case
> the results are not what you want. Read more about recording scripts
> and using them in a batch process under Help > Contents > Automating
> Tasks.
> --
> Fred Hiltz, fhiltz at yahoo dot com

gwen

2007-05-28, 3:17 am

"Spandex Rutabaga" <SpRu@agabatur.xednaps> wrote in message
news:465A0261.910AC9B7@agabatur.xednaps...
>
> Fred Hiltz wrote:
>
> Everything Fred says is good. However, you should be aware of
> some limitations. All the original image values that were
> pushed beyond the limit of 255 units by the original brightness
> adjustment were set to the maximum of 255. Consequently all color
> differences among such pixels were lost. Darkening these pixels
> will simply make them darker but won't bring back image
> information that was destroyed by the original adjustment. In
> future it might be wiser to use Gamma Adjustment (rather than
> Brightness/Contrast) to adjust the overall lightness of the
> image or to use a more sophisticated filter with more control
> such as Levels or Histogram Adjustment (both of which also
> include gamma adjustment among other possibilities).
>
>

Thanks Fred and Spandex. That was really neat. I tried it on 20 images
and was impressed by the ease with which it accomplished a task that
would have taken me a long time.

I have a question about saving the results. In one instance, I used
overwrite, and in anotherm, I saved the new file using the option of 1 for
compression with no chroma subsampling. In both cases, the file size
increased from 44.2 KB to 124 KB.

I could tell no difference between the two methods but wonder which is
preferable. I'm not overly concerned about the file size.

Your suggestion to try changing gamma or using the histogram adjustment
is an excellent idea, Spandex, and I will experiment with it before
doing anything with the originals.

Aside from all of the above, could you tell me if the inherent gamma of an
LCD display is pretty close to that of a CRT display? I'm aware of the
fact that one is digital and the other analog, but wonder if the
input/output linearity is about the same for both.

again, thanks........gwen

Fred Hiltz

2007-05-28, 3:17 am

gwen wrote:
> "Spandex Rutabaga" <SpRu@agabatur.xednaps> wrote:
>
> Thanks Fred and Spandex. That was really neat...
>
> I have a question about saving the results. In one instance, I
> used overwrite, and in another, I saved the new file using
> the option of 1 for compression with no chroma subsampling. In
> both cases, the file size increased from 44.2 KB to 124 KB.
>
> I could tell no difference between the two methods but wonder
> which is preferable. I'm not overly concerned about the file
> size.
>
> Your suggestion to try changing gamma or using the histogram
> adjustment is an excellent idea, Spandex, and I will experiment
> with it before doing anything with the originals.
>
> Aside from all of the above, could you tell me if the inherent
> gamma of an LCD display is pretty close to that of a CRT
> display? I'm aware of the fact that one is digital and the
> other analog, but wonder if the input/output linearity is
> about the same for both.

PSP Batch does not let you set the JPEG compression level
explicitly. Instead it remembers the level you last set by clicking
the Options button in a File > Save As dialog, which was apparently
= 1 in both cases. Your camera used more compression, hence made a
smaller file. PSP decompresses the file into memory, edits it, then
recompresses it to write the new file. The original file's
compression is irrelevant to the new file's size.

LCD monitors for PCs are made to have the same hardware gamma, about
2.2, as CRTs for PCs. Some graphics cards let you change it, which
is not a great idea unless you have the right calibration equipment
and good reason to use it.

The gamma adjustment in PSP uses a similar exponential
formula--hence its name--but is otherwise not related to the gamma
of the hardware. It is just a good way to adjust lightness without
clipping the whites or the blacks.

I will guess that your improperly calibrated CRT monitor simply had
its brightness control too low, causing you to make the pictures too
light so they looked right on it.
--
Fred Hiltz, fhiltz at yahoo dot com

gwen

2007-05-28, 6:18 am

underprocessable