Thu, 25 Oct 2012 01:58:39 +0200 "Xavi" wrote: >I also have analized this case. I have compared the original tiff file generated by printtarg versus the resized, with Ps, tiff file nad the values of every patch is exactly the same.OK. This is not a source the problem. >On another email you commented " I'm using ImageMagic "convert" utility to >crop and resize Argyll targets into desirable format." >What I see that your patches, after this converssion, haven't a regular color. For exampl, if I analize the yellow color patch with Ps, the information of each pixel varies. A pixel has a Lab 243,222,88 and the pixel that limites has a value 242.221,87 [Lab]. This not occurs when resizing with Ps. All the pixels, of a same color patch, have the same Lab value.I've didn't use ImageMagic for preparing Test4.tif. This pixel difference is due to enabled dithering in printtarg. >...I used a resized TIFF file, created without the -D (ÂDither 8 bit TIFF >values down from 16 bit) >Do you think that's important to use the -D option when create the TIFF file?The spatial dithering allows to print arbitrary RGB values, not only INTEGER 0..255, for example, You had to round RGB values from xicclu -fb or -fif to closest integer. With dithering enabled, the dithering algorithm will mix-up the pixels of different but closest values to obtain desirable intermediate value with higher tolerance. You can use 16-bit raster images, but when printing they will be re-quantized down to 8 bit with dithering by Photoshop or another SW. I'm enabling the dithering almost always if I use 8-bit images. I want not to loss intermediate device values.