Android Tutorial Take pictures with the internal camera

Erel · Dec 14, 2010

It is recommend to use the new CameraEx class. It provides more functionality.
The new Camera library allows you to take pictures using the back facing camera.

The following steps are required for taking a picture:
- Initialize a camera object. The Initialize method expects a Panel. The preview images will be displayed on this panel.
- Wait for the Ready event.
- In the Ready event Sub, call Camera.StartPreview to show the images preview.
- Call TakePicture to take a picture.
- The PictureTaken event will be raised with the picture passed as a bytes array (in JPEG format).
- Call StartPreview again to restart the images preview.

Only one process can access the camera at a time. Therefore you should release the camera when your activity is paused.
Usually you will initialize the camera during Activity_Resume and pause it during Activity_Pause.

The following code saves the image:

B4X:

Sub Camera1_PictureTaken (Data() As Byte)
    Dim out As OutputStream
    out = File.OpenOutput(File.DirRootExternal, "1.jpg", False)
    out.WriteBytes(data, 0, data.Length)
    out.Close
    ToastMessageShow("Image saved: " & File.Combine(File.DirRootExternal, "1.jpg"), True)

You can see in the attached code that the "take picture" button is only enabled when the camera is ready.

For now the camera orientation is always set to landscape mode. Usually you will want to force the activity to also be in landscape mode. This is done by checking 'Lansdcape' in Project - Orientations Supported menu.

On the emulator the preview images will show a moving check board.

Swissmade · May 12, 2011

Erel said:
The native Camera object is supposed to return a byte array with the complete data. It seems like a bug in your device. Try to restart your device and see if it helps.

This I have done Erel,

Strange thinks happend.
I have the compleet stream in the Array. See my other thread Sending files with TCP/IP. Sending then image to the server the I get the hole Image.
If Save it I dont get it compleet.

I try to put some DoEvents:BangHead: see whats happend.

Erel · May 12, 2011

DoEvents will not help here.
You should send the file length before sending the file itself. Then in your server you should read until you read the exact length.

Swissmade · May 12, 2011

Erel said:
DoEvents will not help here.
You should send the file length before sending the file itself. Then in your server you should read until you read the exact length.

I mean when i Save it to a file on the device I dont get the hole File.
No Problem I try something else.
Whats important that I get it write on the server.

Thanks for Help Erel
:icon_clap:

basvanbreg · Jun 16, 2011

Just what i need.

I want to see the sample but i. can't download the attachment. i don't have permission or so... help me out please:sign0085:

Erel · Jun 16, 2011

For some reason you appear as an unlicensed user. Please contact support@basic4ppc.com to fix this issue.

giangvi · Jun 17, 2011

Hello Erel,
every time I download the example, I always get this message:

"giangvi, you do not have permission to access this page. This could be due to one of several reasons:

1. Your user account may not have sufficient privileges to access this page. Are you trying to edit someone else's post, access administrative features or some other privileged system?
2. If you are trying to post, the administrator may have disabled your account, or it may be awaiting activation.
3. Please read our forum permissions policy.
"

Can you show me how to solve this?

Erel · Jun 17, 2011

See my post above.

koezuma · Aug 23, 2011

camera with black screean

dear erel,

i try your camera program without modification, but only black screen and take camera button appear on the device. no activity if i click take camera button. why?
i use android 1.6.

best regards
koezuma

:sign0085:

Swissmade · Aug 23, 2011

Take image from Camera

koezuma said:
dear erel,

i try your camera program without modification, but only black screen and take camera button appear on the device. no activity if i click take camera button. why?
i use android 1.6.

best regards
koezuma

:sign0085:

hi koezuma,
If you dont know use this

Dim camera1 As Advancedcamera 'Camera
function Camera1.StartPreview

If this is not working then you have a android version problem.
I hope it helps.

Erel · Aug 23, 2011

Also check the unfiltered logs and see if there is any error message.
V1.6 should work with the camera library.

GiovanniPolese · Oct 25, 2011

Video

Erel
I am wondering myself to be forced to use Java for grabbing videos. Do you expect to activate this facility in B4Android in some time, or it is far from your expectations?
Thanks

Erel · Oct 26, 2011

I will check it next week.

vb1992 · Oct 26, 2011

Record video? That would be nice!:icon_clap:

edited: (link to record video)

http://www.b4x.com/android/help/audio.html#videorecordapp

chfajardo · Nov 21, 2011

Camera - NullPointerException on reading Data()

Hi, Erel!

I have tried your code, and it works fine on my cellphone, but in my tablet it gives me nullPointerException every time a try to take a picture.
The model of my tablet is Coby Kyros MID7024.
Do you have some advice to fix this issue?
On my cellphone, the LoadBitmap() function works sometimes, and sometimes not. What can it be?

Thanks in advance.

Carlos H. Fajardo.

Erel · Nov 21, 2011

You should check the logs and find the error stack trace.

LoadBitmap fails when there is a problem with the image or when there is not enough memory to load the bitmap. The later happens when loading several large bitmaps. The solution in that case is to use LoadBitmapSample instead.

chfajardo · Dec 1, 2011

Camera - NullPointerException on reading Data()

Erel,

Thanks for the reply, but this happens when i am saving data() matrix.
Anyway, i found out that using AdvancedCamera instead of Camera and setting, for instance, camera1.Picturesize(600,800) works fine now.

andrewtheart · Dec 14, 2011

Erel said:
DoEvents will not help here.
You should send the file length before sending the file itself. Then in your server you should read until you read the exact length.

Can you elaborate?

Using HttpUtils and the AdvancedCamera library I can POST images to a server as a byte array (specifically, using InitializePost2)

But in PHP I have absolutely no idea how I'd create a "listener" to read in the byte array until every element has been read in.

Erel · Dec 14, 2011

I will answer in your other post (please do not post duplicate questions).

mcmanu · Jan 1, 2012

Rotate the Panel

Hi,
I have to rotate the panel that i can use the camera in the Horizontal and not in the vertikal format. How can i do this?

Erel · Jan 2, 2012

You can try using Advanced Camera library. It allows you to change the camera orientation (assuming that the device supports this action).

Android Tutorial Take pictures with the internal camera

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