[Note: this post has been rewritten to correct an error. The cause of the error was that Bruce Lindbloom’s desk image on his web site is in the sRGB, gamma 2.20 color space, while I thought it was in the sRGB IEC61966-2.1 color space. That caused some rather large errors, which are much smaller once the… [Read More]

There is a persistent legend in the digital photography world that color space conversions cause color shifts and should be avoided unless absolutely necessary.  Fifteen years ago, there were strong reasons for that way of thinking, but times have changed, and I think it’s time to take another look. First off, there are several color… [Read More]

In the last half-dozen posts, I’ve explored the noise reduction effects and quality of the results from six or seven different downsampling methods. From doing that work, I’ve concluded that there are several choices for someone with a small-pixel camera to produce images that have similar noise characteristics as those made with a large-pixel camera,… [Read More]

Over on the Luminous Landscape forum, Nicolas Robidoux, Bart van der Wolf, Alan Gibson, and others have been working on developing downsampling algorithms. They’re using the command-line image editor ImageMagick as the engine to do the work, so their methodology is to write scripts that call ImageMagick. Some of their algorithms are producing impressive results,… [Read More]

This is the fourth in a series of posts showing images that have been downsampled using several different algorithms Photoshop’s bilinear interpolation Ps bicubic sharper Lightroom export with no sharpening Lr export with Low, Standard, and High sharpening for glossy paper A complicated filter based on Elliptical Weighted Averaging (EWA), performed at two gammas and… [Read More]