Search found 235 matches

by Robert Schleif
October 17th, 2010, 6:27 pm
Forum: Picture Window Support
Topic: Border size when resizing using Crop/Add Border
Replies: 4
Views: 1968

Border size when resizing using Crop/Add Border

When resizing and adding a border using Crop/Add Border, the border width refers to the original size of the image. Most often I want the width of the border in the final, resized image to be a particular value. Obtaining this requires an annoying side calculation of the magnification factor and the...
by Robert Schleif
August 12th, 2010, 10:22 am
Forum: Picture Window Support
Topic: Shadows, 16-bit to 8-bit conversion, brightness transform
Replies: 5
Views: 2489

Re: Shadows, 16-bit to 8-bit conversion, brightness transform

In “The Negative” and “The Print”, Ansel Adams pointed out that the difference in luminosity of some scenes may be as large as 4,000 or more (think HDR), and in other scenes, as small as ten. He also noted that to make a pleasing print, it was necessary in the first case, to compress the important p...
by Robert Schleif
August 11th, 2010, 11:13 am
Forum: Picture Window Support
Topic: Shadows, 16-bit to 8-bit conversion, brightness transform
Replies: 5
Views: 2489

Shadows, 16-bit to 8-bit conversion, brightness transform

The useful dynamic range of many cameras now exceeds eight bits if images are recorded in raw format and if they are then converted to 16-bit tiff (sometimes called 48-bit when counting the three rgb colors). Because computer monitors and prints display eight bits of dynamic range or less, any usefu...
by Robert Schleif
July 18th, 2010, 8:43 am
Forum: Picture Window Support
Topic: Blur and Masking
Replies: 34
Views: 14533

Re: Blur and Masking

The 20 pixel radius of Bilateral Sharpening is too small for blurring a background, and it would be nice to be able to blur with a Guassian radius of 25 to 100 pixels in which a mask could prevent sampling from certain areas. Earlier, Jonathan pointed out the very high computational load that would ...
by Robert Schleif
July 5th, 2010, 4:16 pm
Forum: Picture Window Support
Topic: Blur and Masking
Replies: 34
Views: 14533

Re: Blur and Masking

The expansion solution by MikeG is lovely, and sufficiently simple that I can remember it. The example by Charles2 however, points out the value of a large aperture lens and that images look more natural if they pass smoothly from regions of high sharpness to regions of high blur. This new point rai...
by Robert Schleif
July 3rd, 2010, 6:00 pm
Forum: Picture Window Support
Topic: Blur and Masking
Replies: 34
Views: 14533

Re: Blur and Masking

Mike's expansion method is particularly elegant, and sufficiently simple that I can reproduce it by remembering to expand the flower over the halo generated by blurring. Charles2 however, points out the virtue of a big lens and that a gradual transition between objects in focus and out of focus look...
by Robert Schleif
June 27th, 2010, 4:34 pm
Forum: Picture Window Support
Topic: Blur and Masking
Replies: 34
Views: 14533

Re: Blur and Masking

OK, but perhaps blurring that does not draw information from masked areas could be available as an option? I'd like to significantly blur the backgrounds of flowers, and the present behavior makes this difficult.
by Robert Schleif
June 26th, 2010, 2:42 pm
Forum: Picture Window Support
Topic: Blur and Masking
Replies: 34
Views: 14533

Re: Blur and Masking

The maximum blur radius in bilateral sharpen seems to be 20 pixels, and when the radius is set high, it takes very long to perform the transformation. I'd like to use a radius a lot larger than 20. Den, we both agree that blur samples and averages pixels independently of a mask. All that a mask does...
by Robert Schleif
June 26th, 2010, 8:53 am
Forum: Picture Window Support
Topic: Blur and Masking
Replies: 34
Views: 14533

Blur and Masking

When an unmasked pixel is being blurred, at least with Gaussian blur, nearby pixels are sampled, whether or not they are masked. Consequently, halos are generated around masked objects. It seems more logical to me, and certainly would be more useful, if blurring would only sample unmasked pixels, or...
by Robert Schleif
April 25th, 2010, 4:59 pm
Forum: Picture Window Support
Topic: Micro Contrast
Replies: 9
Views: 6684

Re: Micro Contrast

Here in order of increasing complexity, are six ways of increasing local contrast. Normally, I use number one, but when I need to push it, I use numbers five or six. 1. Unsharp mask, radius 100 (on the order of the sizes of objects), amount, 20-40%. 2. Blur with radius on the order of the sizes of o...