Hi! Newbie here, coming from LaTeX.
There is a relatively common practice in GenAI literature with figures, where a magnification is applied to the images, allowing to show details or just to compare resolution. In LaTeX one can use TikZ with tikzimage and spy/zoombox. At the end, there is a link to a post which illustrates it.
But how magnification can be achieved with Typst and whether CeTZ or any other library is capable of doing it?
Thanks!
Hi. Lilaq has something like this, but it’s more of an emulation:
#import "@preview/lilaq:0.2.0" as lq
#let weierstrass(x, k: 8) = {
range(k).map(k => calc.pow(0.5, k) * calc.cos(calc.pow(5, k) * x)).sum()
}
#let xs = lq.linspace(-0.5, .5, num: 1000)
#let xs-fine = lq.linspace(-0.05, 0, num: 1000)
#show: lq.set-grid(stroke: none)
#lq.diagram(
width: 14cm,
height: 7cm,
ylim: (0, 2),
margin: (x: 2%),
lq.plot(xs, mark: none, xs.map(weierstrass)),
lq.rect(-0.05, 1.5, width: .05, height: .3),
lq.place(
60%,
100% - 1.2em,
align: bottom,
lq.diagram(
width: 5.4cm,
height: 2cm,
margin: 0%,
ylim: (1.5, 1.8),
fill: white,
lq.plot(xs-fine, mark: none, xs-fine.map(weierstrass)),
),
),
)
So we can apply the same concept with CeTZ:
#import "@preview/cetz:0.3.4"
#let unit = 1cm
// Magnify content.
//
// - scale (ratio): magnification scale
// - place-pos (array): position of the magnification
// - pos (array): where in the content to magnify
// - size (array): size of the area to magnify
// - body (content): what to magnify
#let magnify(scale, place-pos, pos, size, body) = {
import cetz.draw: content, rect, line
rect(pos, (rel: (size.first(), -1 * size.last())), name: "a")
content(
anchor: "north-west",
name: "b",
place-pos,
block(
stroke: 1pt,
width: size.first() * unit * scale,
height: size.last() * unit * scale,
clip: true,
std.scale(
scale,
reflow: true,
move(dx: -pos.first() * unit, dy: pos.last() * unit, body),
),
),
)
line("a", "b")
}
And then get:
#import "@preview/cetz:0.3.4"
#import "@preview/lilaq:0.2.0" as lq
#let unit = 1cm
#let canvas = cetz.canvas.with(length: unit)
#let weierstrass(x, k: 8) = {
range(k).map(k => calc.pow(0.5, k) * calc.cos(calc.pow(5, k) * x)).sum()
}
#let xs = lq.linspace(-0.5, .5, num: 1000)
#let xs-fine = lq.linspace(-0.05, 0, num: 1000)
#show: lq.set-grid(stroke: none)
#let image = box(
lq.diagram(
width: 14cm,
height: 7cm,
ylim: (0, 2),
margin: (x: 2%),
yaxis: (ticks: none),
xaxis: (ticks: none),
lq.plot(xs, mark: none, xs.map(weierstrass)),
),
)
// Magnify content.
//
// - scale (ratio): magnification scale
// - place-pos (array): position of the magnification
// - pos (array): where in the content to magnify
// - size (array): size of the area to magnify
// - body (content): what to magnify
#let magnify(scale, place-pos, pos, size, body) = {
import cetz.draw: content, rect, line
rect(pos, (rel: (size.first(), -1 * size.last())), name: "a")
content(
anchor: "north-west",
name: "b",
place-pos,
block(
stroke: 1pt,
width: size.first() * unit * scale,
height: size.last() * unit * scale,
clip: true,
std.scale(
scale,
reflow: true,
move(dx: -pos.first() * unit, dy: pos.last() * unit, body),
),
),
)
line("a", "b")
}
#canvas({
import cetz.draw: *
content((0, 0), anchor: "north-west", image)
magnify(300%, (7, -3.9), (5, -2), (1, 1), image)
})
There are plenty of other variations of this, but most of them are more complicated, for example, if you want to connect all 4 corners with 4 lines, or use another shape, etc.
Here is the yellow circle:
// Magnify content.
//
// - scale (ratio): magnification scale
// - place-pos (array): position of the magnification
// - pos (array): where in the content to magnify
// - diameter (int, float): size of the area to magnify
// - body (content): what to magnify
#let magnify(scale, place-pos, pos, diameter, body) = {
import cetz.draw: content, rect, line, circle, set-style
let color = yellow
set-style(stroke: color)
circle(pos, radius: diameter / 2 * unit, name: "a")
circle(place-pos, radius: diameter / 2 * scale * unit, name: "b")
line("a", "b")
content(
(),
block(
stroke: 1pt + color,
radius: diameter / 2 * scale * unit,
width: diameter * scale * unit,
height: diameter * scale * unit,
clip: true,
std.scale(
scale,
reflow: true,
move(
dx: (-pos.first() + diameter / 2) * unit,
dy: (pos.last() + diameter / 2) * unit,
body,
),
),
),
)
}
#import "@preview/cetz:0.3.4"
#import "@preview/lilaq:0.2.0" as lq
#let unit = 1cm
#let canvas = cetz.canvas.with(length: unit)
#let weierstrass(x, k: 8) = {
range(k).map(k => calc.pow(0.5, k) * calc.cos(calc.pow(5, k) * x)).sum()
}
#let xs = lq.linspace(-0.5, .5, num: 1000)
#let xs-fine = lq.linspace(-0.05, 0, num: 1000)
#show: lq.set-grid(stroke: none)
#let image = box(
lq.diagram(
width: 14cm,
height: 7cm,
ylim: (0, 2),
margin: (x: 2%),
yaxis: (ticks: none),
xaxis: (ticks: none),
lq.plot(xs, mark: none, xs.map(weierstrass)),
),
)
// Magnify content.
//
// - scale (ratio): magnification scale
// - place-pos (array): position of the magnification
// - pos (array): where in the content to magnify
// - diameter (int, float): size of the area to magnify
// - body (content): what to magnify
#let magnify(scale, place-pos, pos, diameter, body) = {
import cetz.draw: content, rect, line, circle, set-style
let color = yellow
set-style(stroke: color)
circle(pos, radius: diameter / 2 * unit, name: "a")
circle(place-pos, radius: diameter / 2 * scale * unit, name: "b")
line("a", "b")
content(
(),
block(
stroke: 1pt + color,
radius: diameter / 2 * scale * unit,
width: diameter * scale * unit,
height: diameter * scale * unit,
clip: true,
std.scale(
scale,
reflow: true,
move(
dx: (-pos.first() + diameter / 2) * unit,
dy: (pos.last() + diameter / 2) * unit,
body,
),
),
),
)
}
#canvas({
import cetz.draw: *
content((0, 0), anchor: "north-west", image)
magnify(300%, (8, -5.3), (5.9, -2.5), 1, image)
})
Should work with raster images, but I haven’t tested that.
Looks like it works perfectly well with images, but you do have to lock both axis, otherwise it will scale incorrectly. For this, you can do
#let image = {
let image = image.with("file.png")
context image(..measure(image(width: 20cm)))
}
#import "@preview/cetz:0.3.4"
#let unit = 1cm
#let canvas = cetz.canvas.with(length: unit)
// Magnify content using circle.
//
// - scale (ratio): magnification scale
// - place-pos (array): position of the magnification
// - pos (array): where in the content to magnify
// - diameter (int, float): size of the circle area to magnify
// - body (content): what to magnify
#let magnify-circle(scale, place-pos, pos, diameter, body) = {
import cetz.draw: content, rect, line, circle, set-style
let color = yellow
set-style(stroke: color)
circle(pos, radius: diameter / 2 * unit, name: "a")
circle(place-pos, radius: diameter / 2 * scale * unit, name: "b")
line("a", "b")
content(
(),
block(
stroke: 1pt + color,
radius: diameter / 2 * scale * unit,
width: diameter * scale * unit,
height: diameter * scale * unit,
clip: true,
std.scale(
scale,
reflow: true,
move(
dx: (-pos.first() + diameter / 2) * unit,
dy: (pos.last() + diameter / 2) * unit,
body,
),
),
),
)
}
// Magnify content using rectangle.
//
// - scale (ratio): magnification scale
// - place-pos (array): position of the magnification
// - pos (array): where in the content to magnify
// - size (array): size of the rectangle area to magnify
// - body (content): what to magnify
#let magnify-rect(scale, place-pos, pos, size, body) = {
import cetz.draw: content, rect, line
rect(pos, (rel: (size.first(), -1 * size.last())), name: "a")
content(
anchor: "north-west",
name: "b",
place-pos,
block(
stroke: 1pt,
width: size.first() * unit * scale,
height: size.last() * unit * scale,
clip: true,
std.scale(
scale,
reflow: true,
move(dx: -pos.first() * unit, dy: pos.last() * unit, body),
),
),
)
line("a", "b")
}
#let image = {
let image = image.with("glacier.jpg")
context image(..measure(image(width: 20cm)))
}
#set page(width: auto, height: auto, margin: 0pt)
#canvas({
import cetz.draw: *
content((0, 0), anchor: "north-west", image)
magnify-rect(500%, (4, -4), (12, -2.6), (1.5, 1.3), image)
magnify-circle(500%, (16, -8), (13, -3.2), 1.5, image)
})
Or, if you want to just edit image, without needing for canvas:
#import "@preview/cetz:0.3.4"
// Magnify content using circle.
//
// - scale (ratio): magnification scale
// - body (content): what to magnify
// - place-pos (array): position of the magnification
// - pos (array): where in the content to magnify
// - diameter (int, float): size of the area to magnify
// - unit (length): unit to use to convert int/float numbers
// - color (length): stroke color
#let magnify-circle(
scale,
body,
place-pos: (0, 0),
pos: (0, 0),
diameter: 1,
unit: 1cm,
color: yellow,
) = {
let canvas = cetz.canvas.with(length: unit)
canvas({
import cetz.draw: content, line, circle, set-style
content((0, 0), anchor: "north-west", body)
set-style(stroke: color)
circle(pos, radius: diameter / 2 * unit, name: "a")
circle(place-pos, radius: diameter / 2 * scale * unit, name: "b")
line("a", "b")
content(
(),
block(
stroke: 1pt + color,
radius: diameter / 2 * scale * unit,
width: diameter * scale * unit,
height: diameter * scale * unit,
clip: true,
std.scale(
scale,
reflow: true,
move(
dx: (-pos.first() + diameter / 2) * unit,
dy: (pos.last() + diameter / 2) * unit,
body,
),
),
),
)
})
}
// Magnify content using rectangle.
//
// - scale (ratio): magnification scale
// - body (content): what to magnify
// - place-pos (array): position of the magnification
// - pos (array): where in the content to magnify
// - size (array): size of the area to magnify
// - unit (length): unit to use to convert int/float numbers
#let magnify-rect(
scale,
body,
place-pos: (0, 0),
pos: (0, 0),
size: (1, 1),
unit: 1cm,
) = {
let canvas = cetz.canvas.with(length: unit)
canvas({
import cetz.draw: content, rect, line
content((0, 0), anchor: "north-west", body)
rect(pos, (rel: (size.first(), -1 * size.last())), name: "a")
content(
anchor: "north-west",
name: "b",
place-pos,
block(
stroke: 1pt,
width: size.first() * unit * scale,
height: size.last() * unit * scale,
clip: true,
std.scale(
scale,
reflow: true,
move(dx: -pos.first() * unit, dy: pos.last() * unit, body),
),
),
)
line("a", "b")
})
}
#set page(width: auto, height: auto, margin: 0pt)
#let image = {
let image = image.with("glacier.jpg")
context image(..measure(image(width: 20cm)))
}
#magnify-circle(
500%,
image,
place-pos: (16, -8),
pos: (13, -3.2),
diameter: 1.5,
)
#magnify-rect(
500%,
image,
place-pos: (4, -4),
pos: (12, -2.6),
size: (1.5, 1.3),
)
Thank you very much, I’d never have come to that, it looks pretty cool!
Hey @Btjk16, welcome to the forum! I’ve changed your question post’s title to better fit our guidelines: How to post in the Questions category
For future posts, make sure your title is a question you’d ask to a friend about Typst. 