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So now let's move on to section four, where we take a look at drawing on images.

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So let's open up this notebook here.

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Let's close off the previous two to one.

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So here we go.

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So now let's look at this chapter.

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Him the chapters pretty cool and pretty useful.

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And it's something that even though it's it's a bit silly, but it's something that we actually do often

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in computer vision, which is putting text on images to four different labels or for whatever reason.

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But it's something you might do quite often just do if you just want to enhance a show of your work.

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So you'll see how how it's done in Open City now.

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So again, let's just load off or input our libraries and motor function or plotting function.

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So now we can do something here.

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Let's firstly create a black blank image.

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So we're going to create an image here five, 12 by 512 by tree, which means it's a color black image

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as opposed to a gray scale black image, which looks the same.

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It's black as again.

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As you can see here, we can make a black and white grayscale one to remember with zeros.

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Everything is going to be dark, dearest, darkest color, which is absence of color, which is black.

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So we can plot this here, and you can see we get two images right here.

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Will be black and gray scale black, if exactly the same thing.

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However, this one is going to take up to three times the memory space because it has three dimensions

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three, five, 12 three times.

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So now let's take a look at see how we can draw a line of all black square.

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So the reason we actually have a watch three dimensional black image here is because we want our blue

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line to show up as blue as opposed to gray.

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So we want to have a color image effectively so quick to open.

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TV has a cool function called a v2.0 line.

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And it takes the input of our image here.

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It takes this is a starting coordinates here, which is zero zero, which is zero zero as a reference

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point.

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You can see this zero here.

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So this is basically the same axis here.

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This is on top.

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It just labels on bottom, but it's the same thing.

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Zero starts here, so it's zero zero here, five 11 here you can see five 11 is all the way here.

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Five, 11, five 11.

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So we're connecting two points here.

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I've already put what what the function here is so we can see we have and then coordinate something

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coordinates color and line thickness.

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So let's take a look at this do this nice little blue line.

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I do encourage you to experiment and do different lines if you want.

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It's quite fun to do this.

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Basically pin playing like a windows pinch or one of those painting programs.

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Except no, you're actually coding.

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And the lines are programmatically which could be interesting to do if you wanted to make something

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more elaborate.

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You can have like rows and rows of these little line functions doing all sort of intricate lines, or

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you can have a polygon or circles, which you'll see below.

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So it's actually a rectangle, that's the next one.

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So actually, I didn't run this.

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So let's just run this for running at sake.

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So now we're going to do a rectangle.

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So rectangles are actually pretty cool because in things like object detectors, you may want to draw

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a box or something or some kind of contour or some sort of region you're looking at in an image.

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So having the ability to draw a box is actually quite useful.

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Surprisingly, so similarly, we have this takes this function takes the image as an input takes it,

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starting with X, which is the top left with X and the opposite with X, which is a bottom right with

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X.

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So we have a top left, bottom right color and thickness again.

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So let's create our blank image here or black canvas we use.

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We use two rectangles.

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You can see it here.

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Now this this function, which I didn't mention previously, this function basically takes the image

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here and manipulates the image itself.

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It's called in function.

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It doesn't have something click.

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It is an output and a function image, and you call it equal to that.

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That's not how this one works.

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It manipulates the image in that line right there.

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Which is something to note because if you wanted to keep the original image as the original, this is

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going to draw a box over that original image.

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So your input variable is has changed, basically.

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So now we can run this and you can see we have this here.

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This cool purple pink?

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Well, I think it's put this purple more in pink, but is this a triangle here?

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So now let's draw some circles so you can see the circle function again is similar.

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However, you don't have a top left and bottom right vertices.

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You have a center and a radius, which is all you need when you want to specify how big a circle.

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In a way, you want to put it just drop percent center in specified radius and it just fills the circle

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here.

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Now you don't actually have to fill if used.

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If you use different value here, it actually wouldn't fill the circle.

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So let's take a look at that and see.

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It's been a while since I actually did this.

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This should just affect.

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Let's take a look.

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Yeah.

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Blindsides so you can see by putting him negative one here, you actually follow through the cycle automatically

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with that color, the color that you actually specified here.

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Color because you can specify any color you want.

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255, 255 255 is all white.

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If you wanted to see it and not, take my word for it, we can run that.

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No, oops.

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And you can see we got a nice wide circle there.

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So let's go back to a green circle, the leaf negative one.

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So now let's move on to polygons.

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So polygons are pretty interesting and cool.

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Remember, I said you can draw a bunch of lines together by having a lot of line functions to create

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something weird.

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Well, you can use it here.

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You can use this polygon function instead.

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What this does, it takes an array of points so you can see carefully.

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Look at this here.

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This is an array one tree hill.

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It's a single, a single array, but you have submarines in it.

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Here we have.

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These are coordinate points.

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So you got this list here, which is 10, 50, 450 and 90 200.

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Whatever the five hundred five fifty five hundred does it a four points here.

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We're going to draw one two three four.

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And this connects back to the last one.

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So let's reshape four points.

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This is how we have to reshape the points here for these four to see V to polyolefins function.

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So this reset function?

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Don't worry about it too much.

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It just actually changes the format around.

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If you wanted to actually see it, you can print it out yourself and take a look at it.

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So we use a C V to pull the lines here to image the points.

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True.

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Basically means we are going to join the last point with the this point.

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The color you want it at and the thickness.

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And there we go.

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Pretty cool.

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Boomerang airplane type.

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Which you there.

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So yes, sir, I did see how it requires a degree to behave that way.

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Basically, what you're doing here, you're just adding in a point in extra dimension in the middle.

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And the reason for that for is just because of how it probably seemed to function the internal function

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inside of poly lines and how it's basically how addict decodes the points here.

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So it's pretty much it's not really that intuitive is not really important to know, but you can see

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the difference in shape here.

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What what this ratio of function did just for your information.

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So now let's look at putting text, which is the key to put text function, which is often something,

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something I use quite often as well.

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You can see this is a variable fonts here.

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I'll show you how to use it and change it quickly.

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So let's create our blank image here and let's create a string string is going to call Hello World.

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And what we're going to do, we're going to use to put text function here.

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So it just takes the image text to display here.

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Bottom left starting point right here, font.

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We specify here font size, color, the color and thickness.

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So we've have all of we have all the stuff we need right now.

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So remember, the bottom of the starting point is actually here.

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So this is where the text starts right now, so we can run this function and we've placed some text

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here.

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Let's try a different font.

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Let's try the complex.

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So, oops, this is just gives us access to the markdown, but you do have access to and we get a nice

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little fancy font here going, which actually don't if you use this one because it looks a bit unprofessional

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sometimes, but you can pretty up pretty easily anything you want using these different fonts here,

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and you can change the color, the thickness, the size position.

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Anything you want to do is within this function.

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So that's quite cool.

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So that now concludes this lesson on drawing on images.

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Hope you find it useful and cool.

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What we're going to do next is transmission's, which is includes translations and rotations, so stay

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tuned for the next lesson.

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Thank you.