HOW TO: Convert an Image To/From Landscape/Portrait Orientations

#1 Posted : Thursday, June 1, 2017 4:18:09 PM(UTC)

Aaron

Groups: Registered, Tech Support, Administrators
Posts: 71

Was thanked: 4 time(s) in 3 post(s)

One of the most pressing needs in publishing today is converting a document of one size to another. Even even going as far as turning a portrait page sideways to landscape orientation or vice versa. For instance, some avatars that are comprised of uploaded images require you to have the uploaded image in a certain orientation (Landscape or Portrait).

The attached Visual Studio project developed in C# demonstrates how developers can use LEADTOOLS to convert their images' orientation from landscape to portrait or vice versa.

The project demonstrates how to perform the conversion in multiple ways:

1. Using the CombineCommand to create a new "background" image which uses the target orientation and pasting the original image on top of it. This would create a new image that appears to have margins around it:

Landscape -> Portrait

Code:


// Generate the new portrait width and height based on the landscape width and height ratio
double ratio = (double)image.Width / (double)image.Height;
double scaledWidth = image.Height * ratio;
double scaledHeight = image.Width * ratio;

using (RasterImage newImage = RasterImage.Create((int)scaledWidth, (int)scaledHeight, image.BitsPerPixel, image.XResolution, RasterColor.White))
{
   CombineCommand cmbCmd = new CombineCommand()
   {
      SourceImage = image.Clone(),
      DestinationRectangle = new LeadRect(0, 0, newImage.Width, newImage.Height),
      SourcePoint = new LeadPoint(0, (image.Height / 2) - (newImage.Height / 2)),
      Flags = CombineCommandFlags.SourceMaster
   };
   cmbCmd.Run(newImage);

   codecs.Save(newImage, @"..\..\output_portrait_combine.jpg", RasterImageFormat.Jpeg, 0);
}

Portrait -> Landscape

Code:


// Generate the new portrait width and height based on the landscape width and height ratio
double ratio = (double)image.Height / (double)image.Width;
double scaledWidth = image.Height * ratio;
double scaledHeight = image.Width * ratio;

using (RasterImage newImage = RasterImage.Create((int)scaledWidth, (int)scaledHeight, image.BitsPerPixel, image.XResolution, RasterColor.White))
{
   CombineCommand cmbCmd = new CombineCommand()
   {
      SourceImage = image.Clone(),
      DestinationRectangle = new LeadRect(0, 0, newImage.Width, newImage.Height),
      SourcePoint = new LeadPoint((image.Width / 2) - (newImage.Width/ 2), 0),
      Flags = CombineCommandFlags.SourceMaster
   };
   cmbCmd.Run(newImage);

   codecs.Save(newImage, @"..\..\output_landscape_combine.jpg", RasterImageFormat.Jpeg, 0);
}

2. Using the CropCommand to crop a section of the image to the target orientation:

Landscape -> Portrait

Code:


using (RasterImage newImage = image.Clone())
{
   // Generate the new portrait width and height based on the landscape width and height ratio
   ratio = (double)image.Width / (double)image.Height;
   scaledWidth = image.Height / ratio;
   scaledHeight = image.Width / ratio;

   CropCommand cropCmd = new CropCommand()
   {
      Rectangle = new LeadRect((int)((image.Width / 2) - (scaledWidth / 2)), 0, (int)scaledWidth, (int)scaledHeight)
   };
   cropCmd.Run(newImage);

   codecs.Save(newImage, @"..\..\output_portrait_crop.jpg", RasterImageFormat.Jpeg, 0);
}

Portrait -> Landscape

Code:


using (RasterImage newImage = image.Clone())
{
   // Generate the new portrait width and height based on the landscape width and height ratio
   ratio = (double)image.Height / (double)image.Width;
   scaledWidth = image.Height / ratio;
   scaledHeight = image.Width / ratio;

   CropCommand cropCmd = new CropCommand()
   {
      Rectangle = new LeadRect(0, (int)((image.Height / 2) - (scaledHeight / 2)), (int)scaledWidth, (int)scaledHeight)
   };
   cropCmd.Run(newImage);

   codecs.Save(newImage, @"..\..\output_landscape_crop.jpg", RasterImageFormat.Jpeg, 0);
}

Here are before and after screen shots of the images:

Landscape -> Portrait
Landscape to Portrait

Portrait -> Landscape
Portrait to Landscape

File Attachment(s):

CSPortraitOrLandscape.zip (691kb) downloaded 382 time(s).

Aaron Brasington
Developer Support Engineer
LEAD Technologies, Inc.


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HOW TO: Convert an Image To/From Landscape/Portrait Orientations