Save Bitmap as PNG with transparency?

[Bjorn Brox]

Hi!

Windows Mobile 6.0, CF 3.5

I noticed that Bitmap.Save(xxx, ImageFormat.Png) (and Gif) does not
preserve transparency when inspecting the image in for example PhotoShop.

I even tried to run through each pixel before the save by executing
if (bmp.GetPixel(x, y) == Color.White)
bmp.SetPixel(x, y, Color.Transparent);
(debug showed that the SetPixel statement was executed)

Does anyone have some solution on how to save a bitmap as PNG (or gif)
where white is made total transparent?

 

[patash]

Hi!

Windows Mobile 6.0, CF 3.5

I noticed that Bitmap.Save(xxx, ImageFormat.Png) (and Gif) does not
preserve transparency when inspecting the image in for example PhotoShop.

I even tried to run through each pixel before the save by executing
if (bmp.GetPixel(x, y) == Color.White)
bmp.SetPixel(x, y, Color.Transparent);
(debug showed that the SetPixel statement was executed)

Does anyone have some solution on how to save a bitmap as PNG (or gif)
where white is made total transparent?

Well instead try setting the white color as transparent in your code
and paint.

Ashish

 

[patash]

Hi!

Windows Mobile 6.0, CF 3.5

I noticed that Bitmap.Save(xxx, ImageFormat.Png) (and Gif) does not
preserve transparency when inspecting the image in for example PhotoShop.

I even tried to run through each pixel before the save by executing
if (bmp.GetPixel(x, y) == Color.White)
bmp.SetPixel(x, y, Color.Transparent);
(debug showed that the SetPixel statement was executed)

Does anyone have some solution on how to save a bitmap as PNG (or gif)
where white is made total transparent?

Hi,
Instead mark the white color transparent while painting.

Ashish

 

[Bjorn Brox]

(e-mail address removed) skrev:

Hi,
Instead mark the white color transparent while painting.

Ashish

The debugger shows that Color.Transparent is Color.White with alpha
channel set to zero.

An initial _graphics.Clear(Color.Transparent) did not help.