Image resizing

The resize samples demonstrate how to scale images to specific dimensions after applying corrections. This is useful for generating thumbnails, web-optimized images, or standardized output sizes.

What these samples demonstrate

The ResizeSample (Linux/macOS) and Sample-Resize (Windows) projects show how to correct an image and then resize it to target dimensions using the SDK's built-in resize function.

Key functions

Key functions used for image resizing:

Function	Purpose
`PFC_Resize`	Resize image to new dimensions
`PFCImageFile` constructor	Allocate destination buffer with target dimensions

C/C++ implementation

The following excerpts are from ResizeAndCorrect.cpp.

Allocate destination image

Before resizing, allocate a destination image buffer with your target dimensions. The PFCImageFile helper class simplifies buffer management.

// Target dimensions: 800x600 pixels
// Parameters: width, height, bytes per pixel, stride
PFCImageFile fileResized(800, 600, 3, 3 * 800);

// Populate PFCIMAGE struct for the destination
PFCIMAGE imageResized;
imageResized.width = fileResized.width;
imageResized.height = fileResized.height;
imageResized.format = im.format;  // Same format as source
imageResized.stride = fileResized.stride;
imageResized.data = fileResized.raw_image;

Perform resize

Call PFC_Resize with the corrected source image and the destination buffer.

// Resize the corrected image
int status = PFC_Resize(&im, &imageResized);

if (status == APPLY_SUCCESS) {
    // Save resized image
    char outputPath[1000];
    sprintf(outputPath, "%s.%dx%d.jpg", inputPath, imageResized.width, imageResized.height);
    fileResized.SaveImageFile(outputPath, 90, false, false);
} else {
    printf("Resize failed with code: %d\n", status);
}

Complete workflow

The typical workflow is: load → correct → resize → save.

// 1. Load image
PFCImageFile originalImageFile;
originalImageFile.LoadImageFile(inputPath, true, NULL);

// 2. Set up PFCIMAGE struct for source
PFCIMAGE im;
im.width = originalImageFile.width;
im.height = originalImageFile.height;
im.stride = originalImageFile.stride;
im.format = (PFCPIXELFORMAT)originalImageFile.pfcImageFormat();
im.data = originalImageFile.raw_image;

// 3. Apply corrections
PFCPARAM param;
PFC_SetParam(param);
PFC_AutoCorrect(&im, NULL, param, -1, NULL, false, NULL);

// 4. Resize
PFCImageFile fileResized(800, 600, 3, 3 * 800);
PFCIMAGE imageResized;
imageResized.width = fileResized.width;
imageResized.height = fileResized.height;
imageResized.format = im.format;
imageResized.stride = fileResized.stride;
imageResized.data = fileResized.raw_image;

PFC_Resize(&im, &imageResized);

// 5. Save
fileResized.SaveImageFile("output_800x600.jpg", 90, false, false);

Calculating dimensions

To maintain aspect ratio, calculate the target dimensions based on the original image.

// Resize to fit within max 1200 pixels on longest edge
int maxDimension = 1200;
int newWidth, newHeight;

if (originalImageFile.width > originalImageFile.height) {
    // Landscape
    newWidth = maxDimension;
    newHeight = (originalImageFile.height * maxDimension) / originalImageFile.width;
} else {
    // Portrait
    newHeight = maxDimension;
    newWidth = (originalImageFile.width * maxDimension) / originalImageFile.height;
}

// Ensure stride is properly aligned (multiple of 4 bytes is common)
int bytesPerPixel = 3;
int stride = ((newWidth * bytesPerPixel + 3) / 4) * 4;

PFCImageFile fileResized(newWidth, newHeight, bytesPerPixel, stride);

Source files

You can find the code snippets in the following files:

Platform	Sample	Path
Linux/macOS	`ResizeSample`	`Linux/ResizeSample/ResizeAndCorrect.cpp`
Windows	`Sample-Resize`	`Win/Sample-Resize/Sample-Resize.cpp`

The C# samples do not include a dedicated resize example. For .NET applications, you can use System.Drawing methods to resize the corrected bitmap before saving.

PFC-SDK Version 10.7.2.1269 built from 4fa849d8101945eea725a08dd0dae5101f090fa0 on 11-10-2025.

Image resizing

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