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Image resize

Hello,

I have a collection of images for my Visual Basic.NET app they are in a .png format which are 32x32 pixels in size and I am trying to find a way of resizing them without looing the quality and detail however, I have not been so successful so far.

Can anyone recommend any other method.
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lincstech
Asked:
lincstech
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2 Solutions
 
xeroxzeroxCommented:
yes ..you can do it on photoshop. make a frame and put it in it.
It's simple.
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Pratima PharandeCommented:
I think you can try this

using System.Drawing;

Bitmap img = (Bitmap)Bitmap.FromStream(FileUploadPost.PostedFile.InputStream);
Bitmap newImg = new Bitmap(maxWidth, maxHeight, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
newImg.SetResolution(72, 72);
Graphics newGraphic = Graphics.FromImage(newImg);
newGraphic.Clear(Color.Transparent);
newGraphic.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
newGraphic.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
newGraphic.DrawImage(img, 0, 0, maxWidth, maxHeight);
System.Drawing.Imaging.ImageFormat format = default(System.Drawing.Imaging.ImageFormat);
string ext = Path.GetExtension(FileUploadPost.PostedFile.FileName);
switch (ext.ToLower())
{
    case ".gif":
        format = System.Drawing.Imaging.ImageFormat.Gif;
        break;
    case ".png":
        format = System.Drawing.Imaging.ImageFormat.Png;
        break;
    default:
        format = System.Drawing.Imaging.ImageFormat.Jpeg;
        break;
}
newImg.Save(myPath, format);

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this is in C# try to convert in VB
refer
http://stackoverflow.com/questions/21367007/asp-net-image-resizing-quality
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lincstechAuthor Commented:
@xeroxzerox

Do you have any tutorials on the photo shop method. ?
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xeroxzeroxCommented:
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Kalpesh ChhatralaSoftware ConsultantCommented:
you can use below Image Resize Free Library.

http://imageresizer.codeplex.com/
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Tom BeckCommented:
I am trying to find a way of resizing them without looing the quality and detail however,

How much quality could there be in a 32 x 32 pixel image? How much bigger do you intend to make the images?

You can't get something for nothing. Photoshop can increase the resolution and the size, but the additional pixel information is interpolated based on the original pixels (Google "image interpolation in Photoshop").  When increasing size and/or resolution, Photoshop takes the original pixels, spreads them out over a larger grid and fills in the spaces between with similarly colored pixels. The added image information is computer interpreted rather than real world. Sharpness is also interpreted and you can vary the amount added by playing with the Bicubic Smoother or Bicubic Sharper settings. But computers cannot pick out the edges of objects in the foreground and background the way the human mind can when looking at a photo. As a result, sharpness cannot be added in a way that improves the separation of objects in the image. To the computer it's all two dimensional. It simply looks for contrasts between adjoining pixels and increases those contrasts to make the image appear sharper. You could increase the size of your 32 x 32 images to 64 x 64 or even go to 128 x 128, but more than that, and the quality will probably be unacceptable.
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lincstechAuthor Commented:
It's not down to making the image bigger its when I resize the image and make it smaller if you resize a 32x32 icon to 16x16 you'll see what I'm talking about or I can attach an icon that I'm using ?
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Tom BeckCommented:
Smaller? Didn't get that from the question.

It definitely depends on your image. Still, there's not much to work with, a 16 x 16 image means 256 pixels total.

Example:
32 x 32 reduced to 16 x 16
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Jacques Bourgeois (James Burger)PresidentCommented:
.png being a raster graphics image format / pixel based(http://en.wikipedia.org/wiki/Raster_graphics), you will always lose some quality when you resize an image, except if very specific cases such as the square in a square of Tom's sample.

In order to enlarge, pixels have to be added. In order to make smaller, pixels have to be removed. Since half pixels do not exist, it's impossible for the system to do a good job. The results are usually less worse when you resize by a factor that is a multiple of 2.

They are usually worst when you start with a small image, such as your 32x32 than if you were working from a bigger image, because the resizer has more information to work with.

Images that resize without losing quality are vector based. Instead of being composed of dots as a .png is, they are composed of instructions that tell how to recreate the image. This enables the system to adjust the pixels for the best possible appearance for a given screen or output peripheral.
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