Android Question Bitmap resize

[Almora]

hi..

            ...........
            Buffer=c.GetBlob("bitid")
            input.InitializeFromBytesArray(Buffer,0,Buffer.Length)
            Dim bitmap1 As Bitmap
            bitmap1.Initialize2(input)
            input.Close
            imageview1.Bitmap=bitmap1
            imageview1.Gravity = Gravity.CENTER
       '     imageview1.Gravity = Gravity.FILL

I want to view a picture from the database. the picture looks. but I can't see the exact size.
is there a method for exact sizing?
thanks..

 

[OliverA]

The Bitmap object has Height and Width properties to determine original size. It also has a Resize method you can use to resize the image (with the option to keep the aspect ratio intact).

 

[Almora]

'    resimv.Bitmap = LoadBitmapResize(dir, filename, resimv.Width, resimv.Height, True)
'    resimv.Gravity = Gravity.CENTER

how can I do similarly.
It needs to maintain its aspect ratio.

 

[John Naylor]

'    resimv.Bitmap = LoadBitmapResize(dir, filename, resimv.Width, resimv.Height, True)
'    resimv.Gravity = Gravity.CENTER

how can I do similarly.
It needs to maintain its aspect ratio.

You can calculate your aspect ratio from your original height / width.

Take your original height. let's say it's 1200 pixels
Take your original width. Say 1600 pixels
Divide the height by the width - 1200 / 1600 = 0.75
Multiply the quotient by the preferred width, e.g. 0.75 * 300 = 225

 

[OliverA]

try

           Buffer=c.GetBlob("bitid")
            input.InitializeFromBytesArray(Buffer,0,Buffer.Length)
            Dim bitmap1 As Bitmap
            bitmap1.Initialize2(input)
            input.Close
            'Which ever side you want to keep, needs to be the smaller of the two values. For example, if you want to resize to a width of 640 and have
            'the height calculated, then the height must be larger then the width.
            'Here we have a fixed width of 640 and have the system calculate the proper height
            bitmap1 = bitmap1.Resize(640, 700, True)
            'The line below would be used if you want the height to be 400 and have the system calculate the width
            'bitmap1 = bitmap1.Resize(600, 400, True)
            imageview1.Bitmap=bitmap1
            imageview1.Gravity = Gravity.CENTER

Update: Slight coding error fixed. Resize returns the newly resized bitmap. I forgot to assign it back to bitmap1.

 

[Almora]

I tried the code .. the picture is not fully visible.

..... Gravity.CENTER





..... Gravity.FILL






must be

 

[Almora]

I read this in the forum.

The bitmaps are never resized, only the internal ImageView is resized.

[B4X] B4XImageView - ImageView + resize modes | B4X Programming Forum

correct me if I'm wrong ..
It is necessary to convert what is taken from the database back to an image file and show it with imageview (Load Bitmap Resize (File.DirRootExternal ..)

 

[OliverA]

I tried the code .. the picture is not fully visible.

1) Make sure that you have the updated code (I forgot to assign the resized image back to bitmap1)
2) You cannot make a square peg fit a round hole. In other words, if the image view is 200x400 and the original source picture is 400x1000 (for example), then you will not be able to fit the source neatly into the image view with the aspect ratio intact. The source picture would convert to 200x500 in this case (with aspect ratio intact). You then either will have an overfill (gravity center) or the picture will be squeezed vertically (fill). In order for neither to happen, your image view needs to be the same aspect ratio as your source image.

 

[Almora]

I tried the last code you fixed.

my image source is gallery. It can be any size picture.

 

[OliverA]

Try

          Buffer=c.GetBlob("bitid")
            input.InitializeFromBytesArray(Buffer,0,Buffer.Length)
            Dim bitmap1 As Bitmap
            bitmap1.Initialize2(input)
            input.Close
            Dim widthRatio As Float = bitmap1.Width / imageview1.Width
            Dim heightRatio As Float = bitmap1.Height / imageview1.Height
            If widthRatio > heightRatio Then
                   bitmap1 = bitmap1.Resize(imageview1.Width, imageview1.Width * 2, True)
            Else
                   bitmap1 = bitmap1.Resize(imageview1.Height * 2, imageview1.Height, True)
            End If
            imageview1.Bitmap=bitmap1
            imageview1.Gravity = Gravity.CENTER

 

[Almora]

that's great


thank you so much