java - Using ZBar (Android) SDK, My Application Is Getting Different ISBNs From The Same Book -

-

i creating application using zbar sdk on android scan books , isbn. have gotten work on physical side. press button, scanner window pops , scans bar code.

the problem comes when application gets isbn scanner, seems scanner either reading bar code incorrectly or not pulling in right data. know how fix issue? thanks. below relevant code, , few screens

    @override public void onclick(view v)  {     //todo add functionallity     if(v.getid() == r.id.scanbutton)     {         intent intent = new intent(this, zbarscanneractivity.class);         intent.putextra(zbarconstants.scan_modes, new int[]{symbol.isbn10, symbol.isbn13, symbol.ean8, symbol.ean13 });         startactivityforresult(intent, zbar_scanner_request);      }  } @override protected void onactivityresult(int requestcode, int resultcode, intent data) {         if (resultcode == result_ok)      {         // scan result available making call data.getstringextra(zbarconstants.scan_result)         // type of scan result available making call data.getstringextra(zbarconstants.scan_result_type)         contenttext.settext("isbn: " + data.getstringextra(zbarconstants.scan_result));         toast.maketext(this, "scan result = " + data.getstringextra(zbarconstants.scan_result), toast.length_short).show();          toast.maketext(this, "scan result type = " + data.getstringextra(zbarconstants.scan_result_type), toast.length_short).show();         // value of type indicates 1 of symbols listed in advanced options below.     }      else if(resultcode == result_canceled)      {         toast.maketext(this, "scanning cancelled", toast.length_short).show();     } }

first screen

second screen

offending bar code

we have been using zbar in production in 1 of our desktop applications. in extract barcode image , use it. though different yours issue same extract barcode live stream.

the issue facing prevalent , error prone. , depends on picture. (in fact observe same behavior zxing, eymbarcode , other open source ones. stable 1 found this). had resort image taking guidelines. below quality factors use avoid it:

the following factors determine detection ability of application:

  1. resolution
  2. focus
  3. lighting , exposure
  4. noise

hence essential above 4 taken care of while picture taken.

  1. resolution: desired barcode occupy significant portion on image. long linear barcodes or dense 2-d symbols, 1 have increase resolution. if resolution decreases below 2 pixels, hard scan barcode.

  2. focus: blurred images highly undesired. portion of barcode consisting of blurry part lead inability of detection.

  3. lighting , exposure: image bright or overexposed can wash out barcodes. image dark or underexposed not provide sufficient contrast scanner. low light levels tend produce noisier images.

  4. noise: random variation of brightness/color can make difficult scan barcode.

  5. angle: preferred have barcode placed either horizontally or vertically placed.

  6. tilt: preferred if camera placed perpendicular image.

the above not solve problems, hope helps


Comments

Post a Comment

Popular posts from this blog

ruby on rails - Is it the correct way to implement belongs_to relation with factory girl? -

-
i have realy easy model. user have role_id depends of role table (id, name) role reference. i want create users of types on rspec test, factory girl. my first idea factory :role name "guest" factory :role_admin name "admin" end factory :role_supervisor name "supervisor" end etc... have lot different roles end factory :user email password '123456' password_confirmation '123456' association :role, factory: :role factory :admin association :role, factory: :role_admin end factory :supervisor association :role, factory: :role_supervisor end etc... have lot different roles end in model have simple method : def is(role_name) return self.role.name == role_name end it's correct way to? realy need create factory role? can make stub function in factory girl each role? i realy new test stuff, thanks. factories should reflect models. class user has_many :products en
Read more

geolocation - Windows Phone 8 - Keeping background location tracking active beyond four hours -

-
i'm in process of developing wp8 app makes use of background location tracking abilities provided os. idea monitor users position , notify them when near types of places. so far seems work fine , when running location tracking works expect. the problem is, seems phone times out background apps after around 4 hours, stopping location tracking. i can understand why microsoft did it, preserve battery life etc. there's not point having background location tracking app has manually restarted every 4 hours! if user chooses run app , made aware of potential battery hit, surely should able run indefinitely - point of course, if system runs out of resources or similar that's fair enough. does have experience this? there must hundreds of others apps in store have run issue have thought? , presumably there must way of keeping location tracking running? i've tried periodically updating live tile (using dispatchertimer) while tracking running doesn't seem enough ke
Read more

Uncaught TypeError: Cannot read property 'parentNode' of null javascript -

-
this code should make element disappear list when dropped on element (called cookiemonster) addevent(cookiemonster, 'drop', function (e) { if (e.stoppropagation) e.stoppropagation(); var el = document.getelementbyid(e.datatransfer.getdata('text')); el.parentnode.removechild(el); return false; }); create auxiliar variable this addevent(cookiemonster, 'drop', function (e) { if (e.stoppropagation) e.stoppropagation(); var el = document.getelementbyid(e.datatransfer.getdata('text')); var aux = el.parentnode; aux.removechild(el); return false; });
Read more