Tag Archives: transparent

Make light pixels transparent in an image in C#

Posted on February 7, 2017 by RodStephens

Recently I had an image and I wanted to make all of the light pixels transparent. Ideally I could simply make the white pixels transparent, but the image was scanned so few of the pixels were pure white. What I … Continue reading →

Posted in graphics, image processing | Tagged Bitmap, C#, C# programming, example, example program, graphics, image processing, ImageAttributes, light pixels, tansparent background, transparent, Windows Forms programming | Leave a comment

Make a tool that creates PNG files with transparent backgrounds in C#

Posted on January 4, 2017 by Rod Stephens

When you use the File menu’s Open command, the following code lets you select a image file. // The image. private Bitmap Bm = null; // Offset for displaying the image. private const int Offset = 10; // Open a … Continue reading →

Posted in graphics, image processing | Tagged C#, C# programming, example, example program, graphics, image processing, MakeTransparent, png, transparency, transparent, transparent background, transparent bitmap, transparent image, Windows Forms programming | Leave a comment

Give an image a transparent background in C#

Posted on January 3, 2017 by Rod Stephens

The Bitmap class’s MakeTransparent method changes all of the pixels with a given color to the transparent color A = 0, R = 0, G = 0, B = 0. When the program starts, the following code makes the background … Continue reading →

Posted in graphics, image processing | Tagged C#, C# programming, example, example program, graphics, image processing, MakeTransparent, transparency, transparent, transparent background, transparent bitmap, transparent image, Windows Forms programming | Leave a comment

Adjust image translucency in C#

Posted on December 9, 2016 by Rod Stephens

The example Use an ImageAttributes object to adjust an image’s brightness in C# uses a ColorMatrix object to scale the red, green, and blue color components of an image’s pixels. You can use a similar technique to scale the pixels’ … Continue reading →

Posted in drawing, graphics, image processing | Tagged adjust opacity, adjust translucency, adjust transparency, C#, C# programming, drawing, example, example program, graphics, image processing, ImageAttributes, Opacity, overlay, overlay images, translucency, transparent, Windows Forms programming | Leave a comment

Make a Region from non-transparent pixels in C#

Posted on September 2, 2016 by Rod Stephens

The example Make shaped PictureBoxes in C# sets the Region property of two PictureBox controls to circular regions. That works well in that example where the images are round volleyballs with transparent backgrounds, but it would be hard to manually … Continue reading →

Posted in algorithms, geometry, graphics, image processing | Tagged algorithms, C#, C# programming, example, example program, geometry, graphics, image processing, pixels, regions, transparency, transparent, transparent pixels, Windows Forms programming | Leave a comment

Remove part of an image in C#

Posted on April 25, 2015 by Rod Stephens

This example lets you remove part of an image. It lets you load an image file and then click and drag to select an area on the image. When you release the mouse, the program generates two new images: an … Continue reading →