ImgView for Unix now supports RGB and CMYK ICC profiles in JPEG, and RGB ICC profiles in TIFF and PNG. Please note that the color management code is still rather immature.
Monday, February 24, 2014
I have converted all my PNG format pictures (back) to TIFF. I have been using this format in the past, before I put the pictures online. Since the TIFF support in web browsers is close to non‐existent, I decided to use PNG until I found a better solution. Nowadays computers are much faster than they were in the past, and it is finally feasible to convert TIFF to PNG on the fly for web display, albeit with some delay when processing very large images.
Thanks goes to Bob Friesenhahn for his valuable input regarding TIFF technicalities, and his role as the driving force behind the excellent GraphicsMagick software package, which I find much more stable and bug‐free than ImageMagick, which should perhaps be renamed as “ImageTragick”? Just kidding.
Sunday, February 16, 2014
Sunday, January 26, 2014
On page 14 in the Exif 2.3 specification, under 4.4.3, “Pixel Composition and Sampling”, the following is stated:
“When compressed data is used, the combination shall be Y:Cb:Cr = 4:2:2 or Y:Cb:Cr = 4:2:0.”
Why the heck isn’t a combination of 4:4:4 (i.e. no sub‐sampling) allowed? This will produce the highest quality JPEG compressed images, and many times there is a noticeable difference between using 4:4:4 and using 4:2:2 or 4:2:0. Incomprehensible.