gimp

 Basic

resolution, defined as the ratio between an image's size in pixels and its physical size (usually in inches) when it is printed on paper.

expressed as ppi—pixels per inch

The resolution is usually 72 or 96ppi

 

   Physical size: 340x190 mm

diag size=10 sqrt(1517) mm =389.487=15.3341 inch

   resolution: 1920x1080 px 

diag res  = 120 sqrt(337) = =2202.907 px

 

dpi = 120 sqrt(337) *25.4 /10 sqrt(1517) = 143.66 dpi 

for wolfarm  Sqrt[1920^2+1080^2]*25.4 /Sqrt[190^2+340^2]

1 inch=25.4 mm

 

dpi=diagonal res in px / diagonal physical size in inches

 

 windows > single-window Mode

file>new or ctrl+n

adjust:  width,height,unit

advance: x,y-res,colorspace,precision(bit),gamma,color-profile,fill with,comment

tools groups:

selection tools : rectangular(R),ellipse(E),free(F),foreground,fuzzy(U),by color select(shift+O),intelligent Scissors(I)

 

paint tools: bucket fill(shift+b),gradient(g),pencil(p),eraser(shift+e),airbrush(a)

ink(i),mypaintbrush(y),clone(c),heal(h),presprective colne,blur/sharpen(shift+u)

smudge(s),dodge/burn(shift+d)

 

transform tools: align(q),move(m),crop(shift+c),rotate(shift+r),scale(shift+s)

shear(shift+h),presprective(shift+p),3d transform(shift+w),unified transform(shift+t),handle transform(shift+l),flip(shift+f),cage transform(shift+g) wrap transform(w)

paths(b)

text(t)

GEGL operation..

color picker(o)

Measure(shift+m)

zoom(z)

toolbox (ctrl+b)

default colors (d)

swap colors (x)

move tool (m) : move layers,selection and other objects

alignment tool(q) : align or arrange layers or other objects

 

rectangle(r),ellipse(e) select tool 

free(f) : select hand drawn region with free or polygon segments

scissor(i) : select shape using intelligent edge-fittig

foreground select tool

 

https://docs.gimp.org/2.10/en/