Mike Chaney's Tech Corner

Typically before I print any image I will adjust the Output Levels in Photoshop. Via the Levels dialog I'll compress the tonal range of the image by say setting the black output point to be 10, and the white point to be 254. Reason being is that the I know my printer/paper/ink combination will render anything less that 10 to be solid black, and antying above 254 to be pure white. If there is any detail at these extremes the final print will loose it. Although on screen it looks 'wrong' when printed the difference can give you give an improvement.

(This trick came from the Fine Art Printing for Photographers book - that also recommends QImage!)

It would vastly improve my workflow if I could do this via QImage. Although I've seen the levels filter it is not obvious to me that this achieves what I want to do. Anybody suggest if indeed this possible?

Thanks!
Matthew

Sure!
Go into the batch screen and select the curves tab.
In the controls on the right you will see Loc, In, and Out.
There are 16 points on the grid, but we are interested in the lowest and the highest.
Location, type a zero. In is zero and OUT type 10.
Say OK to the pop up live box.
Next type in LOC 16, the highest spot on the grid.
In the out box, type in 254/ Again click OK.
Done, Save filter on the way out,,,,
That will do it.
If you need screen shots, let me know.

Fred

The levels filter is pretty standard in the way it works, Moving the Highlight and Shadow sliders towards the middle increases contrast and clips those regions.
I think you can do what you want by using a curve. Just move the top end down and the bottom end up. Once each end point is selected, you can enter the numbers directly.
Once done for one image, save the filter, from File/Save ... and you can then apply it to any number of images selected in the queue or as thumbs with a right click, Apply Predefined Filter.
Terry

Great minds speak alike  ;D
You beat me to it again  >:(
Terry

That's OK, son!
Seven more posts and you will be a HERO member just like me. ::) ??? ;D

Seriously, for a moment!
You see where we had different methods of achieving the same result.
That's really good so people get to choose which they like best.
I would rather type in a number than trust my hands and the mouse.... others may be sure handed.
Fred

 ;D Thanks - that's great. I've opted to go with the typing option; don't think this late on a Thursday I could be that accurate with the mouse!

I was very hopeful that it could be done -QImage does everything else I could ask of it.

Thanks again
Matthew.

Thanks a lot, Fred.

What about making this process more visual? Playing around converting images into black&white with Nik Silver Efex there is a tool to visualize the Zone System Map. Hovering over the zone index you can see the relative grey values on the image. Such a tool would be a great help to check the tone values for the final print when adjusting the curves or the loc values.

The image is from the article about Silver Efex at http://www.northlight-images.co.uk/reviews/plugins/silver_efex.html
(http://www.northlight-images.co.uk/content_images/sfx/92_zone_5.jpg)

If you are asking for this feature, to read the RGB values of each pixel, that's already in Qimage in both the batch screen as well as the Refine RAW image screen.
Not sure exactly what you are looking for.

If you are looking to compare zones or area sections of your image for gray values, you can place your B&W image or create one using the predefined filter for B&W in Qimage into the queue.
Go into the batch screen of Qimage. Drag draw a full image crop. Then click View and turn on Rule of Thirds grid.
Now you have all the sections you will need; hover the mouse over any section, and you have your gray readings over on the right side.
Fred

Thanks a lot Fred. Qimage is full of features - but it's quite difficult to find theme. I think I have to study the whole manual during the Christmas holidays.