ImageInterpolation

High quality, multi-platform pascal image interpolation (resizing/scaling) using TBitmap (VCL/FMX)

Supported sampling filters:

Nearest neighbor<br> Bilinear<br> Cosine<br> Hermite<br> Quadratic<br> Gaussian<br> Spline<br> Lanczos<br> Mitchell<br> CatmullRom (bicubic)<br>

Introduction

I was having a very hard time finding image scaling (resizing) code that is free to use, simple to integrate and high in quality. I finally managed to find usable code in mark mauder's vampyre imaging library, but it was wrapped in a lot of code that overly complicated the specific use function I needed. <br><br> I ended up modifying the code to make it simpler to use with both the VCL and FMX versions of TBitmap.

Usage:

<b>StretchResample</b>(const SrcImage: TBitmap; SrcX, SrcY, SrcWidth,SrcHeight: LongInt; var DstImage: TBitmap; DstX, DstY, DstWidth, DstHeight: LongInt; Filter: TSamplingFilter; WrapEdges: Boolean = False); overload;

Example of resizing an image 50% :

ResizedImage.Width := SourceImage.Width div 2;<br> ResizedImage.Height := SourceImage.Height div 2;<br> <b>StretchResample</b>(SourceBitmap,0,0, MySourceBitmap.Width, MySourceBitmap.Height,ResizedBitmap,0,0,ResizedBitmap.Width,ResizedBitmap, sfLanczos,False);

Notes:

For simplicity, I only supported 32bit (R/G/B/A) bitmap.<br> The code is pure pascal, there are no low level CPU-specific optimizations.

Credits:

Based on the Vampyre Imaging Library by Marek Mauder<br> https://imaginglib.sourceforge.net

Modified for simplicity of use with TBitmap VCL/FMX classes by Yaron Gur