Beginner PHP Tutorial - 162 - Watermarking Images Part 2 Video Lecture | PHP for Absolute Beginners: From Novice to PHP Master - Web Development

so now we need to come down and create a
watermark height and also a watermark
width value and we can easily do this
using the image SX function so it will
type image SX and here we just need to
supply one argument and that's just the
image we've already loaded in so we've
got the watermark height so the image
watermark hi using this function and
just supplying the already opened image
so we'll do exactly the same thing for
the width as well okay so now we've
successfully loaded in the watermark and
the watermark height and width from this
watermark that we've already created
we've basically here created a new image
file in Gd but from this so we've almost
duplicated the file if you like okay so
the next thing to do is set up our
canvas now we need to set up our canvas
by basically using our image to create
true color function and that's going to
go inside an image and image a variable
called image sorry so the function we
need to use is image create true color
and we need to supply this with two
values and that is going to be watermark
height in fact where it's the width
first so we're always taking a whip
first and water mark height now we're
going to redefine the same variable and
we're going to say image create from
JPEG so this is the important part we're
creating the image from our source so
remember up here we called our value
source or the value that we're reading
in source so we can just pop in source
there so you can see now why I created
this variable it's a lot easier than
then keep referencing this long if you
like get method way of reading in a
value so now what we need to do is get
the image size so by image size I mean
the image as in the
phone image that I showed you earlier
this is the size of the source image
that we're loading in using this line
here so what we want to do is we want to
create a new variable so we'll name it
properly we'll call it image underscore
size and we're going to be using a
function called get image size
now get image size isn't actually a GD
function itself this can be used without
Gd so if you find that you might need
this function elsewhere and you might
need to use this function and you don't
have Gd installed you're more than
welcome to use this as it's not part of
the GD library so obviously we're
getting the image file from the image
size sorry from the source like I said
earlier so we just supply it with the
argument source which is the source data
we're reading in now you'll notice just
just to make know that we use in the
image SX function here and here to grab
the watermark height and width however
why are we using this get image function
here the reason we'll get image size
function here the reason we're using
this down here as opposed to the image
SX is we haven't loaded in the source
well we have but what we want to do is
we want to read the get image size from
the source which is the file that we're
supplying with so we're using this and
without loading the image in first and
as we've done here create image from
pier we've used this function here but
here we're just using the get image size
and this is going to read it in as an
array so now what we can do is we can
set two variables that's x and y now
these two variables are going to be the
positioning for they're going to be the
positioning for our water map now
remember I said that we're going to have
it 10 pixels from the bottom and 10
pixels from the side so we need to take
this into account when we're - in values
because let's say my text editor at the
moment was an image the top here would
be at 0 and then we'd go all the way
down here positively and all the way
down here positively so what we want to
do is we want to start here and minus 10
and minus 10 so we can end up around
here then we can display our watermark
here so let's change this X variable and
like I said image size is read in as a
array and the first element of the array
so element 0 let's just type it out so
you can see what we're doing is equal to
the width of the image so the first one
which is 0 is is equal to the image
width so now what we can do is say the
image width overall minus the watermark
width remember we got the watermark
height and width over here earlier I've
just noticed that the I've supplied the
wrong function in here image sy is for
height and image SX is for the width so
let's just change these around so
they're in order as we're supplying them
so yeah sorry about that if you go back
if you're following this tutorial as it
is we've got image as X and whites we've
got X and wife the width and the height
so the watermark width is now going to
be minus 10 but like I said I want it 10
pixels away width wise now height wise I
want it 10 pixels away as well but this
time for the image size which is now an
array we want that to 1 because that's
going to represent the height so one is
representing the height so let's do
exactly the same we're using exactly the
same structure we want to say watermark
height minus 10 okay so let's just recap
on what we've done we've loaded the
image in as a filename we've created the
logo which is the watermark evidently
we've created that in from a PNG files
we're using a PNG file we've grabbed the
width and the height of the watermark so
we can do things with it down here we've
created an image and loaded in our image
that we've created from our JPEG so
we've image crate from JPEG source which
is the file name that we've loaded
and we've grabbed the image size and
we've created the X&Y position for the
watermark which is ten pixels away from
the edge of the image okay so the next
thing to do is to use the image copy
merge function now this has got lots of
parameters that we're going to throw at
it some of which we need to discuss some
of which we probably don't but I'm going
to try and go through all of them so the
image copy merge function looks like
this now what is this function going to
do this function is responsible for
taking one image and basically merging
it with another image and we're going to
say we're going to well give give the
parameters to this function of how we
want to merge and by merging we're doing
exactly the same thing as applying a
watermark onto our image