Imageview strange behaviour

copiloto · Sep 11, 2012

Hi everybody,

I have extracted a piece of code from forum to manipulate pictures or images. However, it shows a strange behaviour (or I can't see my error)...

The code:

Dim c As Canvas
Dim b As Bitmap
Dim i As ImageView

b.Initialize(File.DirRootExternal, "picture.jpg")
i.Initialize("")
Activity.AddView( i, 0, 0, 4000,3000)
c.Initialize(i)

--It seems that "b" bitmap hasn't anything to be with the rest of code, but...

If "i" dimensions are big (like the example), i get a imageview error: "imageview has stopped" and program closes. But not in case of small dimensions, like 1500x1000.

First, I thought that it was a imageview memory problem. However, if I delete b.initialize(File.Dir........) line, now none error shows and the program runs fine...

What could I do to avoid deleting this line and enabling adding big views?

Erel, could it be that i use ICS instead of Gingerbread?

Thanks!

Erel · Sep 11, 2012

First you should check the logs and find the error message (which is most probably an out of memory error).

When you initialize the canvas object, a bitmap is created with the same size as the view's size. As the ImageView is very large, you are running out of memory.

copiloto · Sep 11, 2012

Hi Erel,

I checked the logs and yes, it shows a out of memory message.

My project is easy: charging a internal (from dirroot) photo into a view. Then, use Canvas, to play with the picture. Finally, save it to phone memory.

But first of all, I would need to load the original picture without losing quality into a view, so, I suppose the view should be resized as the picture size,

Please, a little help would be appreciated.

Best regards.

Erel · Sep 11, 2012

What is the size of the image? If it is too large then you will not be able to load it without losing quality (or to load only parts of the image).

copiloto · Sep 11, 2012

Erel, all pictures are 3264x2448 pixels.

Some time ago, I worked with this code using Gingerbread. I have recovered it and it's exactly the same that in the first post. It worked fine using that OS, and using the same resolution: before had a SG2 and now a SG3, but photos are always taken in max resolution (about 3 Mb per photo).

Dim c As Canvas
Dim b As Bitmap
Dim i As ImageView
Dim brect As Rect

b.Initialize(File.DirRootExternal, "picture1.jpg")

i.Initialize("")
Activity.AddView( i, 0, 0, b.Width, b.Height)
i.Visible=False

brect.Initialize(0,0,b.Width, b.Height)

c.Initialize(i)

c.DrawColor(Colors.White)
c.DrawBitmap(b, brect, brect)

please, any idea?

Thanks you Erel

Best regards.

Erel · Sep 12, 2012

The process uses all of the available memory. You will need to use a different approach.
The simplest solution is to use LoadBitmapSample and to resize the image.

copiloto · Sep 12, 2012

Thanks you Erel. I'll try that way.

Informatix · Sep 12, 2012

You can also save a lot of memory by reducing the colors and removing the alpha channel. It does not change a lot the visual quality (personnaly, I can't see the difference on most images). Drawback: your images cannot be transparent.
To do this, use the BitmapPlus library provided with the CustomGallery class. There's a function named ReduceColors.

copiloto · Sep 12, 2012

Thanks you Informatix for your support.

Still I don't know that libray (fortunately, there are so much ), but seems another solution to my code. You say that the two images are practically equals... good news!

I'll test Erel and you code and report here my results.

Best regards friend!

Imageview strange behaviour

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