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PHP GD Image at Pixel Level User of Signature Tutorial
We’re getting there, but we are not there yet. Sound familiar?! Yes, to learn how to do something, it often requires the breaking up of the problem into bits. But no spoiler alerts today, as you continue on our journey … to who knows where?!
Yesterday’s PHP GD Image at Pixel Level Signature Web Storage Tutorial got us “projecting” scribble data, our signatures, to a pixellated image data source.
That work yesterday involved HTML …
creating
signatures via this downloadable HTML signature_signature
html (with thesechanges and supervising thechanged Javascript signature_signature
… and for today’s purposes thechanges to the Javascript signature_signaturejs represented the biggest changes to have canvas geometry being projected onto a pixellated image data source.
Where do we do this interfacing? Read down from Signature Signature Supervisor PDF Writing Tutorial through the blog posting to see us work up from that initial “signature” idea into a “user of signatures” supervisor with this liverun showing a canvas that can “project” these new pixellated images now, using the HTML user_of_signature_signaturehtml (which changed in this way for those purposes).
So please hang on while we think about piecing some of these ideas into concepts to “kick us down the road” towards our destination … no, we’re not just going to celebrate “bin night” … but you’re getting warmer.
Stop Press
The “child” PHP pixellatephp (that changed in thisway and that you can try for yourself anexample positive live run) now accepts the (non-negative) or …
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… argument to have a white background rather than the default black one, with the pixellated images created. We’d like to thank this very useful link.
Previous relevant PHP GD Image at Pixel Level Signature Web Storage Tutorial is shown below.
PHP GD Image at Pixel Level Signature Web Storage Tutorial
With yesterday’s PHP GD Image at Pixel Level Signature Tutorial pixellating of a signature, behind the scenes there were HTTP Cookies used as a mechanism to store signature data. Today, we have a dual purpose, that being …
- signatures are a good candidate to start using web storage (localStorage – stores data with no expiration date) rather than HTTP Cookies, as there is about 10mB to play around with using this method … as well as …
- when creatingsignatures via this downloadable HTML signature_signaturehtml (with thesechanges and supervising thechanged Javascript signature_signaturejs) we now show a pixellated view, like a negative, of the signature (with all the web browser sharing functionality) along with the dataURI image already created
Just to reiterate on web storage, that was introduced with HTML5 …
With web storage, web applications can store data locally within the user’s browser.
Before HTML5, application data had to be stored in cookies, included in every server request. Web storage is more secure, and large amounts of data can be stored locally, without affecting website performance.
Unlike cookies, the storage limit is far larger (at least 5MB) and information is never transferred to the server.
Web storage is per origin (per domain and protocol). All pages, from one origin, can store and access the same data.
Previous relevant PHP GD Image at Pixel Level Signature Tutorial is shown below.
PHP GD Image at Pixel Level Signature Tutorial
Yesterday’s PHP GD Image at Pixel Level Geometry Tutorial set us up for more organizational uses of our pixel level image web application of late. We continue on with that idea, today, with the idea of a signature, and go right back to the Signature Signature Primer Tutorial scribble in a canvas functionality (as the source of our co-ordinates for a signature) and ready the PHP pixellatephp (that changed in thisway) to accept …
- map/area element HTML input data … like we deal with “legend” functionality as mentioned in Legend for and from HTML Map Element Web Server Tutorial (and its ilk) … (all the way) down to (the pared down essence that is a) …
- co-ordinate list of comma separated (x,y) values that is “pen down” as the default but +0,0, or ; can be indicators of “pen up”
… the latter of which we take from the “signature” web application (via Google Chrome Developer Tools) over to the “legends” functionality legend_via_maphtm that changed in thissmall way (and that you can try for yourself with this liverun link) to add another new button to link to the PHPpixellate live run type functionality.
Maybe you can see where we are heading with all this, but we need to walk before running?! This link to “scribble” canvas work is a step in itself, and if you are new to the idea of “scribbling” on canvas then you’ll need to sidetrack with that Signature Signature Primer Tutorial link way above to get all this in context. Chow for now.
Previous relevant PHP GD Image at Pixel Level Geometry Tutorial is shown below.
PHP GD Image at Pixel Level Geometry Tutorial
We’re off jumping again (post yesterday’s PHP GD Image at Pixel Level Animation Tutorial “chicken” work) a.k.a. …
On a (web application) “tool” project, is it the chicken or the egg that drives you? Sometimes, for us, we jump around. For us, depending on the nature of the “tool” we enjoy trying to …
- make the “child” generic … the “egg” above
- interface interestingly from the “parent” usefully … the “chicken” above
… because it occurs to us, with the “egg”, so far we’ve just been throwing “game like” …
$x = rand(0, $width);
$y = rand(0, $height);
… randomosity regarding co-ordinates used to pixellate “point” data. But suppose, today, we open the door to some order, some mathematical geometry ideas?! We’ve come up with the following additional parameterization ideas (not interfering with anything else that has come before … ie. “forward compatibility”), namely …
- coords … comma separated (x,y) co-ordinate set pairs that, by default, represent “pen down” rasterizations (our best “thought bubble” word for pixellations not in “point” form but in “pen down” “plotting” form … from the early “scanning” days of laser printers and even earlier days of data plotters … that “rasterize” linear data into “pixellated” form) … including a “+” sign at the start of “x” or “y” values is your way of defining “pen up”
- closecoords … as above, but join last to first as well (or just mention to say this about the coords value)
- circle … circle information comma separated (cx,cy,radius) sets
- arc … relevant to circle in the form of clockwise arc in degrees to allow or the comma separated (start,end) of clockwise arc in degrees starting with the zero degrees (north) bearing as zero
… and you’ve got the beginnings of some “orderly” geometry, and some “pen up/pen down” thoughts (and we recommend insomniacs try chanting “pen up”, “pen down” very sombrely for however long it takes rather than envisaging “pigs” … now that’s almost as ridiculous as baaaaa baaaaaaas), simple though it is, up to now.
Again, you can try this for yourself at this “child” “standalone” liverun link for the PHP pixellatephp that changed in thisway for today’s extended geometry (and pen up/pen down logic) choices.
Previous relevant PHP GD Image at Pixel Level Animation Tutorial is shown below.
PHP GD Image at Pixel Level Animation Tutorial
Yesterday’s PHP GD Image at Pixel Level Outputs Tutorial was a tilt back to getting the “hard working duck” PHP child process more user friendly, and don’t know if the PHP’s newfound …
“parent” “body” (or other) element background image
… clang any bells in your head regarding possibilities, but it did for us regarding how to start using that PHP “child” iframe functionality in terms of an animation (effectively). Supposing we “start” (and, no doubt “start” is just that) with an HTML “parent” web application that just consists of …
- table element with one row and three columns for now … and (a bank of) …
- iframe elements
… respectively providing …
- where to place animation … and …
- means by which to create the animation
… because when you consider what “animation” consists of, we now have the wherewithal to do it in that …
- an “animation” is a set of …
- moving
- images
… where …
- the “moving” is worked by timed (via Javascript setTimeout method) creation of (table) cellular background
- “images” pixellated by the “child” iframe PHP “tool” web application (unchanged from yesterday’s work)
… moved fast enough to help the human mind recognize it as “animation”, whose HTML supervisory “parent” code can be downloaded as build_night_skyhtml and tried with this liverun link.
Previous relevant PHP GD Image at Pixel Level Outputs Tutorial is shown below.
PHP GD Image at Pixel Level Outputs Tutorial
On a (web application) “tool” project, is it the chicken or the egg that drives you? Sometimes, for us, we jump around. For us, depending on the nature of the “tool” we enjoy trying to …
- make the “child” generic … the “egg” above
- interface interestingly from the “parent” usefully … the “chicken” above
You could class yesterday’s PHP GD Image at Pixel Level Background Tutorial as a (baark, baark baark baark) “chicken” moment, enjoying writing a quirky “parent” for the “Image Pixellating” “child” iframe PHP code, even prompting an (important) improvement in its abilities “opacity” wise.
Today, though, you may think of it as stepping back to the “Primer” tutorial, but to us is sometimes the way projects “roll”, in that we think of a whole lot more functionality parts for the “egg” (“child” iframe PHP image pixellator). These new functionalities can all be classed as …
forms of output
… changes, where we can envisage “parent” web applications that will demand far more flexibility than just offering the “parent” yesterday’s sole “output” (mode) option of …
image data in a "child" iframe created via PHP's
header('Content-Type: image/png');
imagepng($gd);
… line of thinking. With incredibly useful help from this useful link, thanks (which, incidentally, appeared up the top of the list of this Google search) we were reminded of how that PHP code lines above could be “melded” into …
// header('Content-Type: image/png');
ob_start();
imagepng($gd);
$image_data = ob_get_contents();
ob_end_clean();
$image_data_base64 = base64_encode($image_data);
… to end up with, in the PHP variable $image_data_base64 above a dataURI of the image pixellated by our (“child” iframe supervised, perhaps) PHP web application, and opening the door to all manner of (additional “output” driven) interfacing (or standalone) possibilities like …
- “standalone” “image” data presented in an HTML img element, as in …
//www.rjmprogramming.com.au/PHP/pixellate.php?mode=image&height=600&width=590&size=8&zeroes=2
- “standalone” “div” image data encased in an HTML div element, as in …
//www.rjmprogramming.com.au/PHP/pixellate.php?mode=div&height=600&width=590&size=8&zeroes=2
- “standalone” “canvas” image data placed into in an HTML canvas element, as in …
//www.rjmprogramming.com.au/PHP/pixellate.php?mode=canvas&height=600&width=590&size=8&zeroes=2
- “standalone” “body” element background image
- “parent” “image” data presented in an HTML img element, as in …
- “parent” “div” image data encased in an HTML div element, as in …
- “parent” “canvas” image data placed into in an HTML canvas element, as in …
- “parent” “body” (or other) element background image
You can try this for yourself at this “child” “standalone” liverun link for the PHP pixellatephp that changed in thisway for today’s extended “output” choices.
Previous relevant PHP GD Image at Pixel Level Background Tutorial is shown below.
PHP GD Image at Pixel Level Background Tutorial
Yesterday’s PHP GD Image at Pixel Level Primer Tutorial had us musing ….
Do you feel this web application has the genericity to be a “tool”? Spoiler alert … we think so.
… and so here we are, today, with the first idea regarding using that PHP code as a “tool”, a “background image iframe” tool, using two (of the usual “three amigos”, z-index having gone walkabout due to “relevance deprivation syndrome”, today) of our usual “overlay” suspects …
- position:absolute property (teamed with top:0px and left:0px)
- opacity
We encase yesterday’s PHP work into an HTML iframe “child” element, and rather than relying on the “parent” supervisory (and new) HTML pixellatehtml to control opacity via the opacity of the HTML iframe element (which we may still allow for … we’ll see) we opt to make the “child” HTML iframe PHP be that little more flexible by allowing for pixellatephp change in thisway to allow for a tailored calling mechanism regarding “opacity” via …
imagecolorallocateimagecolorallocatealpha‘s fifth “alpha” (ie. 127=transparent, 0=opaque) parameter
… that is user controllable via “&opacity=1.0” type of URL bit where (1.0=opaque, 0.0=transparent) usage.
The parent’s job using this PHP “child” would be to set some transparency to an HTML “iframe” call of the PHP to cover the window, where we call into play the Javascript window.getComputedStyle method to resize the PHP “child” to full window dimensions, on the proviso that any parameters the user uses to call the “parent” HTML don’t override this “default” width and height of background image (ie. PHP “child” iframe) settings.
Guess the other job of the “parent” is to “mean” something, and so we write some content on the “theme” of “Lyrics of Songs about Stars” because the background image effects you get with the “pixellated” PHP GD calls remind us of the nighttime sky, and stars, and you can see this in action with today’s liverun link.
Previous relevant PHP GD Image at Pixel Level Primer Tutorial is shown below.
PHP GD Image at Pixel Level Primer Tutorial
A great place to start learning about the serverside language PHP is to read the webpage Image Processing and GD because PHP is great in so many ways regarding image creation and manipulation.
The GD methods (down to the pixel level, with the first one) we use are …
What we parameterize is …
- width of image
- height of image
- density of pixels created
- size of conglomeration of pixel (rectangular “blob”)
Today’s PHP code you can download via this pixellatephp link and try it via this liverun link. We kind of like some of the images as below …
//www.rjmprogramming.com.au/PHP/pixellate.php?height=600&width=890&size=6&zeroes=4
//www.rjmprogramming.com.au/PHP/pixellate.php?height=600&width=890&size=8&zeroes=2
//www.rjmprogramming.com.au/PHP/pixellate.php?height=600&width=490
Do you feel this web application has the genericity to be a “tool”? Spoiler alert … we think so.
You can see this, also, at WordPress 4.1.1’s PHP GD Image at Pixel Level Primer Tutorial.
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