Scale JPGs to size depending on cropped or fit.

This commit is contained in:
Jonas Diemer 2026-01-13 16:53:37 +01:00
parent 77827efe92
commit 22097d5113
4 changed files with 14 additions and 9 deletions

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@ -382,7 +382,7 @@ bool Epub::generateCoverBmp(bool cropped) const {
if (coverImageHref.substr(coverImageHref.length() - 4) == ".jpg" || if (coverImageHref.substr(coverImageHref.length() - 4) == ".jpg" ||
coverImageHref.substr(coverImageHref.length() - 5) == ".jpeg") { coverImageHref.substr(coverImageHref.length() - 5) == ".jpeg") {
Serial.printf("[%lu] [EBP] Generating BMP from JPG cover image\n", millis()); Serial.printf("[%lu] [EBP] Generating BMP from JPG cover image (%s mode)\n", millis(), cropped ? "cropped" : "fit");
const auto coverJpgTempPath = getCachePath() + "/.cover.jpg"; const auto coverJpgTempPath = getCachePath() + "/.cover.jpg";
FsFile coverJpg; FsFile coverJpg;
@ -401,7 +401,7 @@ bool Epub::generateCoverBmp(bool cropped) const {
coverJpg.close(); coverJpg.close();
return false; return false;
} }
const bool success = JpegToBmpConverter::jpegFileToBmpStream(coverJpg, coverBmp); const bool success = JpegToBmpConverter::jpegFileToBmpStream(coverJpg, coverBmp, cropped);
coverJpg.close(); coverJpg.close();
coverBmp.close(); coverBmp.close();
SdMan.remove(coverJpgTempPath.c_str()); SdMan.remove(coverJpgTempPath.c_str());

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@ -200,7 +200,7 @@ unsigned char JpegToBmpConverter::jpegReadCallback(unsigned char* pBuf, const un
// Internal implementation with configurable target size and bit depth // Internal implementation with configurable target size and bit depth
bool JpegToBmpConverter::jpegFileToBmpStreamInternal(FsFile& jpegFile, Print& bmpOut, int targetWidth, int targetHeight, bool JpegToBmpConverter::jpegFileToBmpStreamInternal(FsFile& jpegFile, Print& bmpOut, int targetWidth, int targetHeight,
bool oneBit) { bool oneBit, bool crop) {
Serial.printf("[%lu] [JPG] Converting JPEG to %s BMP (target: %dx%d)\n", millis(), oneBit ? "1-bit" : "2-bit", Serial.printf("[%lu] [JPG] Converting JPEG to %s BMP (target: %dx%d)\n", millis(), oneBit ? "1-bit" : "2-bit",
targetWidth, targetHeight); targetWidth, targetHeight);
@ -242,8 +242,12 @@ bool JpegToBmpConverter::jpegFileToBmpStreamInternal(FsFile& jpegFile, Print& bm
const float scaleToFitWidth = static_cast<float>(targetWidth) / imageInfo.m_width; const float scaleToFitWidth = static_cast<float>(targetWidth) / imageInfo.m_width;
const float scaleToFitHeight = static_cast<float>(targetHeight) / imageInfo.m_height; const float scaleToFitHeight = static_cast<float>(targetHeight) / imageInfo.m_height;
// We scale to the smaller dimension, so we can potentially crop later. // We scale to the smaller dimension, so we can potentially crop later.
// TODO: ideally, we already crop here. float scale = 1.0;
const float scale = (scaleToFitWidth > scaleToFitHeight) ? scaleToFitWidth : scaleToFitHeight; if (crop) { // if we will crop, scale to the smaller dimension
scale = (scaleToFitWidth > scaleToFitHeight) ? scaleToFitWidth : scaleToFitHeight;
} else { // else, scale to the larger dimension to fit
scale = (scaleToFitWidth < scaleToFitHeight) ? scaleToFitWidth : scaleToFitHeight;
}
outWidth = static_cast<int>(imageInfo.m_width * scale); outWidth = static_cast<int>(imageInfo.m_width * scale);
outHeight = static_cast<int>(imageInfo.m_height * scale); outHeight = static_cast<int>(imageInfo.m_height * scale);
@ -550,8 +554,8 @@ bool JpegToBmpConverter::jpegFileToBmpStreamInternal(FsFile& jpegFile, Print& bm
} }
// Core function: Convert JPEG file to 2-bit BMP (uses default target size) // Core function: Convert JPEG file to 2-bit BMP (uses default target size)
bool JpegToBmpConverter::jpegFileToBmpStream(FsFile& jpegFile, Print& bmpOut) { bool JpegToBmpConverter::jpegFileToBmpStream(FsFile& jpegFile, Print& bmpOut, bool crop) {
return jpegFileToBmpStreamInternal(jpegFile, bmpOut, TARGET_MAX_WIDTH, TARGET_MAX_HEIGHT, false); return jpegFileToBmpStreamInternal(jpegFile, bmpOut, TARGET_MAX_WIDTH, TARGET_MAX_HEIGHT, false, crop);
} }
// Convert with custom target size (for thumbnails, 2-bit) // Convert with custom target size (for thumbnails, 2-bit)

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@ -8,10 +8,10 @@ class JpegToBmpConverter {
static unsigned char jpegReadCallback(unsigned char* pBuf, unsigned char buf_size, static unsigned char jpegReadCallback(unsigned char* pBuf, unsigned char buf_size,
unsigned char* pBytes_actually_read, void* pCallback_data); unsigned char* pBytes_actually_read, void* pCallback_data);
static bool jpegFileToBmpStreamInternal(class FsFile& jpegFile, Print& bmpOut, int targetWidth, int targetHeight, static bool jpegFileToBmpStreamInternal(class FsFile& jpegFile, Print& bmpOut, int targetWidth, int targetHeight,
bool oneBit); bool oneBit, bool crop = true);
public: public:
static bool jpegFileToBmpStream(FsFile& jpegFile, Print& bmpOut); static bool jpegFileToBmpStream(FsFile& jpegFile, Print& bmpOut, bool crop = true);
// Convert with custom target size (for thumbnails) // Convert with custom target size (for thumbnails)
static bool jpegFileToBmpStreamWithSize(FsFile& jpegFile, Print& bmpOut, int targetMaxWidth, int targetMaxHeight); static bool jpegFileToBmpStreamWithSize(FsFile& jpegFile, Print& bmpOut, int targetMaxWidth, int targetMaxHeight);
// Convert to 1-bit BMP (black and white only, no grays) for fast home screen rendering // Convert to 1-bit BMP (black and white only, no grays) for fast home screen rendering

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@ -260,6 +260,7 @@ void SleepActivity::renderCoverSleepScreen() const {
if (SdMan.openFileForRead("SLP", coverBmpPath, file)) { if (SdMan.openFileForRead("SLP", coverBmpPath, file)) {
Bitmap bitmap(file); Bitmap bitmap(file);
if (bitmap.parseHeaders() == BmpReaderError::Ok) { if (bitmap.parseHeaders() == BmpReaderError::Ok) {
Serial.printf("[SLP] Rendering sleep cover: %s\n", coverBmpPath);
renderBitmapSleepScreen(bitmap); renderBitmapSleepScreen(bitmap);
return; return;
} }