Tag Archives: transparency

Make an image with rounded corners and a transparent background in C#

Posted on June 27, 2019 by RodStephens

Recently I wanted to make an image for a gift card that had rounded corners. Unfortunately the Graphics class does not have a method to draw rectangles with rounded corners. Fortunately, I have already described the key method in my … Continue reading →

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Resize images in C#

Posted on June 21, 2019 by RodStephens

You can use MS Paint to easily resize images. Unfortunately, it won’t preserve transparency if you save the result. I often need to resize transparent images so I finally got around to writing this example. It lets you resize images … Continue reading →

Posted in drawing, graphics, image processing | Tagged , , , , , , , , , | 7 Comments

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 →

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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 , , , , , , , , , , , , | 15 Comments

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 →

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Scale images and save them in C#

Posted on August 29, 2016 by RodStephens

Occasionally when I’m writing a book or article, I need to scale images and then save them. MS Paint does this easily, but it loses any transparency information when it saves images. This program lets you scale images and then … Continue reading →

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Make a form fade out until it disappears in C#, Part 2

Posted on November 3, 2015 by RodStephens

The example Make a form fade out until it disappears in C# makes a form fade out when the user clicks the form’s Close button, but there are several other ways the user can close the form without it fading … Continue reading →

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Make a form fade out until it disappears in C#

Posted on November 3, 2015 by Rod Stephens

Normally when you close a form it disappears. This example shows how you can provide a different effect by making the form fade out until it vanishes. (Like a ghost or a politician’s promises after election day.) A form’s Opacity … Continue reading →

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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 →

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