brought notes up-to-date

1 files changed, 12 insertions, 0 deletions

diff --git a/tech/how to downsize images and keep them sharp.txt b/tech/how to downsize images and keep them sharp.txt
new file mode 100755
index 0000000..b4f3c62
--- /dev/null
+++ b/tech/how to downsize images and keep them sharp.txt
@@ -0,0 +1,12 @@
+title: How to Downsize Images and Keep Them Sharp 
+date:  20140731 13:27:28
+tags:  #gimp #photos #webdev
+
+
+When you size down an image you may get moires or jagged edges due to spatial frequency folding. The solution is to pre-blur the picture before sizing down. The rule is simple, if you size down by X, pre-blur with a Gaussian blur with a radius of X. For example, if you take an image from from 2000px to 400 (1:5), you would use a 5px blur radius.
+
+Then resize your image with scale image (resize in PS) and apply smart sharpen to sharpen up the details.
+
+This works because that pre-blur step (provided you do it right, using just enough, but not too much) doesn't end up softening the result any more than a direct downscale. If done correctly it removes information that will be lost in the resize anyway.
+
+based on: http://gimpforums.com/thread-image-quality-and-resizing
\ No newline at end of file