Looking Beyond the Lens I

Introduction:
Visualizing image enhancement at the time of a camera's shutter release is not always possible.   This becomes next to impossible if the captured image needs recovery from camera setting and photography errors.   But if a good image, exposed and focused well with good white balance, is captured, then the enhancing process can be essentially concentrated on producing a superior image from the camera download image.   The following is a workflow that incorporates the '3Tone Range Adjustment Procedures' and simulated plus/minus compensated exposures resulting from the use of the Filter transform for the 'capture' adjustments and then uses the Filter transform again with a mask for added 'creative' effects.   Workflow1 describes the steps taken for both the 'capture' and 'creative' adjustments for this image.

   
Click on an image for a larger image version. . . . .(c) IMAGEs by DEN  2005

The left image is a Canon S45, super-fine jpg 24-bit color camera download image.   On the right is an enhanced image version, resulting from 'capture' and 'creative' adjustments.

For your own trials and comparisons, a 600x800 pixel, medium resolution image for Window_ori.jpg is available for download.   Window_ori.jpg will be refered to as Img1 in the subsequent workflow.

Workflow1:   'Capture' adjustments using three 'complex tone range' masks with simulated plus/minus image exposures, followed by 'creative' enhancements.

Comment:  Step 1 checks and adjusts the camera download image for 'full dynamic tone' range.   It is important that at least initially, the starting enhancement image retain all of its tones and be expanded if needed to have full tone range. This way, the maximum amount of image data is retained.   Later enhancement steps may include 'clipping' some highlight and shadow tones for special 'effects', increasing the overall image contrast, for example.   The Brightness Curve transform in 'Log Histogram' [or 'High' Expanded Histogram - PWP3.5] mode is used.   While the check and expansion can be performed in the Levels&Color transform, it is not as sensitive to retaining small quanitites of tones in the shadows and highlights as the Brightness Curve in 'Log Histogram' mode.   See 'Main Image Example 3Tone Range Highlights Workflow' for an example of why this could be important.
Step 1:   Open or click on 'Img1' and open the Brightness Curve transform in HSV color space and from the OPT drop downs, select 'Log Histogram'.   Note the change in histogram detail when switching from 'Linear' and 'Log' histogram modes, particularly where the histogram bars start and end on the horizontal axis of the 10x10 grid.   The left side is the 'black' point and the right side is the 'white' point.   Move the left horizontal arrow right ['black' point] until it is where the left side histogram bars start.   In this case, about 2%.   The right horizontal arrow ['white' point ] is already at where the right side histogram bars end.   If this had not been the case, then the right horizontal arrow would have been moved left to where the right side histogram bars ended.   Click OK, creating 'Img2'.   Discard 'Img1'.


Screen Shot 1: Checking for and expanding to 'full tone'.

Comment:  Step 2 creates two image versions, one simulating a minus compensated exposure and another simulating a plus compensated exposure.   As only partial tone ranges of these compensated exposure images will be utiltized, it is not important how the overall image versions appear.
Step 2.1: Click on 'Img2' and open the Filter transform, set amount = 100, Method = Additive, Filter = 'Img2', and EC = 1.00, Click APPLY, creating 'Img3'.


Screen Shot 2.1: Creating the minus compensated exposure image version.

Step 2.2: Click on the Filter transform, change Method = Subtractive, and click OK, creating 'Img4'.


Screen Shot 2.2: Creating the plus compensated exposure image version.

Comment:  In Steps 3, 4, and 5, '3Tone Range Adustment Procedures' and complex highlight, shadow, and mid-tone tone range masks will be used with the nominally exposed image version and the simulated minus/plus exposure image versions to complete the 'captive' adjustments.   It is interesting to note that this process nominally simulates 'Extending Dynamic Range' and is done with a single, well exposed, 24-bit color, jpg image.
Step 3.1:  Click on 'Img2' and open the Mask Tool - Brightness Curve, and APPLY a complex highlight tone range mask of 70->100% tones with a Blur = 35.   A detailed highlight tone range mask workflow is described here.

Step 3.2:  Click on 'Img2' with the 'active' mask of Step 3.1 applied and open the Composite - Blend transform where Input Image = 'Img2', white = 100, black = 0, Input Mask = 'active' 3.1 mask, Overlay = 'Img3', amount = 100.   Click OK, creating 'Img5'.   Cancel Mask Tool and discard Img3.


Screen Shot 3: Darken, increase contrast and saturation of the 70->100% tones.


Step 4.1:   Click on 'Img5' and open the Mask Tool - Brightness Curve, and APPLY a complex shadow tone range mask of 0->30% tones with a Blur = 10.   A detailed shadow tone range mask workflow is described here.

Step 4.2:   Click on 'Img5' with the 'active' mask of Step 4.1 applied and open the Composite - Blend transform where Input Image = 'Img5', white = 100, black = 0, Input Mask = 'active' 4.1 mask, Overlay = 'Img4', amount = 100.   Click OK, creating 'Img6'.   Cancel Mask Tool and discard Img5.


Screen Shot 4: Lighten, decrease contrast and saturation of the 0->30% tones.


Step 5.1:   Click on 'Img6' and open the Mask Tool - Brightness Curve, and APPLY a complex mid-tone range mask of 30->70% tones with a Blur = 35.   A detailed mid-tone range mask workflow is described here.

Step 5.2:   Click on 'Img6' with the 'active' mask of Step 5.1 applied and open the Color Curves transform where Input Image = 'Img6', Input Mask = 'active' 5.1 mask, white = 100, black = 0, form a HSV,V SMOOTH CURVE = [0,0], [15,0], [35,25], [65,80], [85,100], [100,100], form a HSV,S SMOOTH CURVE = [0,0], [40,45], [80,100], [100,100].   Click OK, creating 'Img7'.   Cancel Mask Tool and discard 'Img6'.


Screen Shot 5: Apply a brightening 'S' contrast and increase saturation of the 30->70% tones.

Comment:  In Step 5.2, the Color Curves transform was used to change the 'black' and 'white' points, apply a brightening 'S' contrast curve, and slightly increase the mid and high saturations of the masked 30->70% tone range.   See Addendum1 for a fuller description and detail of the Color Curve transform HSV,V and HSV,S curve suggestions.

This completes the 'capture' adjustments, now for enhancement changes needed for 'creative' concept. The complex tone range masks used in the preceding steps and the resulting 'Img7' should look the following:

Screen Shot 6: The 'Complex Tone Range' masks.


Screen Shot 7: The 'captive' adjusted image, 'Img7'.


Comment:  In Step 6, a 'mask-sun' mask is created and used with the Filter transform to simulate sun dappling on the bricks and foilage of the image.
Step 6.1:   Create an image area highlighting mask, 'mask-sun'.   This was done by clicking on 'Img7' and opening the Mask Tool - Paint option and using a soft sided medium radius brush, painting image specific areas: bricks with transparency = 0 and foilage with transparency = 25, then APPLY Blur = 15, leaving the Mask Tool 'active' on 'Img7'.


Screen Shot 8: Paint brush masking of image areas for special emphasis and effects.

Step 6.2:  Click on 'Img7' and open the Filter transform, where the Mask='mask-sun'; white = 100 and black = 0; Filter = RGB = 100, 98, 90; Method = Additive; EC=1.10; click APPLY, creating 'Img8'.   The suggested RGB filter values were taken from an actual 'sun dappled' image for this time of year and location.


Screen Shot 9: Lighten image areas to simulate sun dappling.   Use the ReadOut Tool to check for highlight clipping/posterization.

Comment:   See the DL-C Message Board thread, 'PWP & the Filter Transform - a workflow' for an alternative suggestion for a filter color selection and why the ReadOut Tool is used to check for clipping/posterization when the Filter transform's Exposure Compensation is set to a value >1.
Step 6.3:  Click on the Filter transform and set Input = 'Img8'; Mask='mask-sun'; white = 0 and black = 12.5; Filter = 'Img8'; Method = Additive; EC=1.00; click OK, creating 'Img9'.   This step subtlely adds contrast and saturation between the Step 6.2 sun dappled and the non-sun dappled image areas.


Screen Shot 10: Slightly darken, increase contrast and saturation of non-sun image areas to increase contrast with sun areas.

Comment:   'Img9' is nearly the final version.   Final checks/adjustments to preference for 'full dynamic range'; 'color balance'; 'sharpening'; and composition should be performed.   The additional steps taken to obtain the final version shown above are:
Step 7:  Click on 'Img9' and open the Levels&Color transform in HSV color space, expand to 'full dynamic range', click OK creating 'Img10'.

Step 8:  Click on 'Img10' and open the Color Balance transform.   The 'auto color balance' feature indicated no color balancing needed.   Cancel the transform.

Step 9.1:  Click on 'Img10' and open the Sharpen transform in USM method, add Local Contrast Enhancement [LCE] by applying USM amount = 10, radius = 40, and threshold = 0; click APPLY, creating 'Imag11'.

Step 9.2:  Click on the Sharpen transform in USM method, set Input = 'Img11' and apply USM sharpening: amount = 25, radius = 1 and threshold = 3; click OK, creating 'Img12', the final image version posted at the top of this tutorial [re-sized for posting].

Step 10:  While it is hard to give up any of the enhanced image area, a possible crop for composition would be a landscape orientation at an 8 x10 inch ratio.   I was originally attracted to this image because of the perspective and texture of the bricks, motar, and window frame with the softening and opposing curves of the foilage with the possibility of enhancing the reflection details.   The reflection really is not all that interesting, but then during the post-processing, I wondered what this image would look like with sun dappling the brick and foilage...


Reflections - Roeder Home Window, Bellingham, WA   Nov 2005


Comment:   A comparison of the Before and After histograms:

Screen Shot 11: Before and After histograms.


You are welcome to see other IMAGEs by DEN.
Last Update: 060129 rev 3 -- revised comment for Step 6.3