| Re: Reading & Displaying Latex Rendered images [message #178573 is a reply to message #178572] |
Mon, 02 July 2012 20:54   |
Jerry Stuckle
Messages: 2598
Registered: September 2010
Karma:
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Senior Member |
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On 7/2/2012 1:00 PM, Fastian wrote:
> On Monday, July 2, 2012 6:41:03 PM UTC+5, Jerry Stuckle wrote:
>> On 7/2/2012 9:35 AM, Jerry Stuckle wrote:
>>> On 7/2/2012 7:24 AM, Fastian wrote:
>>>> On Monday, July 2, 2012 3:53:13 PM UTC+5, Jerry Stuckle wrote:
>>>> > On 7/2/2012 2:42 AM, Fastian wrote:
>>>> >> On Friday, June 29, 2012 6:20:45 PM UTC+5, Jerry Stuckle wrote:
>>>> >>> On 6/29/2012 6:24 AM, Fastian wrote:
>>>> >>>> I am developing an application for the university. One basic
>>>> >>> > module/ section of this application is Data Entry. The data
>>>> >>> > is entered using Latex (Latex is a type setting language
>>>> >>> > and is not a WYSIWYG language). The tex software converts the
>>>> >>> > latex code into the required image. For better understanding
>>>> >>> > visit the following link:
>>>> >>>> http://www.forkosh.com/mathtexpreview.html
>>>> >>>>
>>>> >>>> You can see that on entering Latex code, the desired output
>>>> >>> > is obtained which is actually an image. This image is produced
>>>> >>> > by the Tex software and is being fetched and displayed on this
>>>> >>> > page. Another way to get that image is as follows:
>>>> >>>> <img src="http://www.forkosh.com/mathtex.cgi?$c=a+b$" alt=""
>>>> >>>> border=0 align=middle>
>>>> >>>>
>>>> >>>> My issue is that I want to get the image generated due to the
>>>> >>> > rendering of the Latex code and then display it after re-sizing
>>>> >>> > and then want store it in the MYSQL database.
>>>> >>>>
>>>> >>>> As I dont know the name of the image produced due to rendering
>>>> >>> > that's why I can not pick the image with its name. Therefore I
>>>> >>> > tried using function "file_get_contents". Though it returns
>>>> >>>> some garbage values on echo but what next?
>>>> >>>>
>>>> >>>> I need to know that how can I proceed further or suggest some
>>>> >>> > better way to deal with these issues especially while dealing
>>>> >>> > with LateX rendering. Thanks!
>>>> >>>>
>>>> >>>
>>>> >>> You don't show the code you're trying to use, so it's all a guess
>>>> >>> as to
>>>> >>> what's wrong. There are many possibilities.
>>>> >>>
>>>> >>> If you're going to display an image, you need to send it as an image.
>>>> >>> My guess is that you're displaying it as text.
>>>> >>>
>>>> >>> Web pages are sent with a content-type of text/html. But if the web
>>>> >>> page contains an image, the browser makes a second request to the
>>>> >>> server
>>>> >>> for the image. The image will be sent with a content-type of
>>>> >>> image/jpeg, image/gif, etc. So the first thing you need to do is
>>>> >>> ensure
>>>> >>> you are sending the correct header when displaying it (in this case it
>>>> >>> should be image/gif) (obviously this needs to be done in a separate
>>>> >>> script from the rest of the page and accessed with an <img= tag).
>>>> >>>
>>>> >>> So what you could do is in your test page, put something like:
>>>> >>>
>>>> >>> <img src="testimg.php" ....>
>>>> >>>
>>>> >>> Then in your testimg.php file, fetch the file with file_get_contents
>>>> >>> then display it with the correct headers, i.e.
>>>> >>>
>>>> >>> header ('Content-type: image/gif');
>>>> >>>
>>>> >>> Of course, if this is the only thing on your test page (it's sending
>>>> >>> NOTHING else), you can skip the <img= ...> tag and just send the
>>>> >>> correct
>>>> >>> content-type at the start of your script.
>>>> >>>
>>>> >>> --
>>>> >>> ==================
>>>> >>> Remove the "x" from my email address
>>>> >>> Jerry Stuckle
>>>> >>> JDS Computer Training Corp.
>>>> >>> jstucklex(at)attglobal(dot)net
>>>> >>> ==================
>>>> >>
>>>> >> Pls have a look on the code:
>>>> >> As you suggested my testing.php file code is as follows:
>>>> >>
>>>> >> <?
>>>> >> $image = file_get_contents('users.gif');
>>>> >>
>>>> >> header('Content-Type: image/gif');
>>>> >>
>>>> >> //imagegif($image); // I also tried to display image with imagegif
>>>> >> but it also didnt work.
>>>> >>
>>>> >> ?>
>>>> >> The code of getimage.php file is as follows:
>>>> >> <html>
>>>> >> <img src="testing.php">
>>>> >> </html>
>>>> >>
>>>> >> But the image is NOT displayed on the browser.Where I am wrong?
>>>> >> Both php files and image (users.gif) is present in the same directory.
>>>> >> I have also noticed that <img src= ""> do not work on the page where
>>>> >> you have used header('Content-Type: image/gif'); ......... why?
>>>> >>
>>>> >
>>>> > Where are you outputting the image? file_get_contents() does not output
>>>> > anything.
>>>> >
>>>> > And no, <img src=..."> is an html command, and valid in pages with
>>>> > content-type of text/html.
>>>> >
>>>> > I think your first problem is not understanding how html works. A
>>>> > response has one content-type. A typical web page will have a
>>>> > content-type of text/html, and will contain html code. <img src=...> is
>>>> > an html command.
>>>> >
>>>> > Tags like <img src=...> (and many others) will cause an additional
>>>> > request to be made to the server. If the content-type of the response
>>>> > is image/gif, then the browser will only process it as an image. If it
>>>> > is not a valid image, the browser will ignore it.
>>>> >
>>>>
>>>> Ok. I got your point. But as it is the requirement of my project to store
>>>> the complete question as an image in addition to storing latex text.
>>>> Therefore I need to process the images (both question + options) and
>>>> have to make them transform into a complete question.
>>>> Therefore I thought that file_get_contents() may be helpful in this
>>>> case as it then enable me to use imagecopy () and other functions.
>>>> what you say?
>>>>
>>>
>>> Why would a customer care whether the question is stored as a single
>>> image or separate entries? In over 40 years of programming I've never
>>> had such a requirement in a project. I admit I've had some stupid
>>> requirements in the past - but I've always been able to convince the
>>> customer why it should not be done that way. All part of being a
>>> successful consultant.
>>>
>>> I would go back to the customer and explaining why it is a bad idea and
>>> convince the customer to change the requirement.
>>>
>>
>> To clarify: by stupid requirement I mean having to put the question and
>> all the answers together into one image.
>>
>
> :)
> Actually the application I am going to develop as a web app was developed
> by someone else as a desktop app. That application has several issues
> and most of the issues are on the side of data entry. Moreover due to
> some other reasons now there is a need to develop a web based app
> for Question entry. The test generation which is the other part of
> the app is very much stable. The previous developer has kept the whole
> question as one image in the DB just for the sake of view while pick
> and choose of the question during the process of test generation. He
> was of the view that just for the sake of preview why should he pull
> the raw latex code and render it every time and then display. He
> thought it is better to keep the whole question as one image because
> it is just for preview purpose. Hope you got the logic now.
>
> I know that there are other alternatives to solve this very scenario
> but as I said that test generation part of the app is stable and
> secondly I am short of time therefore I decided to restrict myself
> with the old design so that nothing else be disturbed. And yes
> the latex text is stored in separate fields and eventually used
> for the generation of test.
>
Yes, developers are not necessarily smart. However, it sounds like you
aren't going to be able to use much of the previous code anyway, and
doing it right shouldn't take longer than trying to muscle what you have
into a bad design. It will also be more flexible and maintainable.
--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex(at)attglobal(dot)net
==================
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